LTE: Introduction, evolution and testing
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LTE: Introduction, evolution and testing

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UMTS Long Term Evolution, LTE, is the technology of choice for the majority of network operators worldwide for providing mobile ...

UMTS Long Term Evolution, LTE, is the technology of choice for the majority of network operators worldwide for providing mobile
broadband data and high-speed internet access to their subscriber base. Due to the high commitment LTE is the innovation platform
for the wireless industry for the next decade.
This class will provide the basics of this fascinating technology. After attending this course you will have an understanding of
OFDM-principles including SC-FDMA as the transmission scheme of choice for the LTE uplink. Multiple antenna technology (MIMO),
a fundamental part of LTE, will be explained as well as its impact on the design of device and network architecture. We’ll give a quick
introduction into the evolution of this technology including future upgrades of LTE features like multimedia broadcast, location based
services and increasing bandwidth through carrier aggregation.
The second part of the course will provide an overview including practical examples and exercises on how to test a LTE-capable device
while performing standardized RF measurements such as power, signal quality, spectrum and receiver sensitivity. We’ll address how
to automate these measurements in a simple and cost-effective way. We will introduce application based testing by demonstrating
end-to-end (E2E), throughput and application testing using the Rohde & Schwarz R&S®CMW500 Wideband Radio Communication
Tester. Examples of application tests are voice over LTE, VoLTE or Video over LTE.

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LTE: Introduction, evolution and testing LTE: Introduction, evolution and testing Presentation Transcript

  • UMTS Long Term Evolution (LTE)technology intro + evolutionmeasurement aspectsReiner StuhlfauthReiner.Stuhlfauth@rohde-schwarz.comTraining CentreRohde & Schwarz, GermanySubject to change – Data without tolerance limits is not binding.R&S® is a registered trademark of Rohde & Schwarz GmbH & Co. KG. Trade names are trademarksof the owners. 2011 ROHDE & SCHWARZ GmbH & Co. KG Test & Measurement Division - Training Center -ROHDE & SCHWARZ GmbH reserves the copy right to all of any part of these course notes.Permission to produce, publish or copy sections or pages of these notes or to translate them must firstbe obtained in writing fromROHDE & SCHWARZ GmbH & Co. KG, Training Center, Mühldorfstr. 15, 81671 Munich, Germany
  • Technology evolution path 2005/2006 2007/2008 2009/2010 2011/2012 2013/2014GSM/ EDGE, 200 kHz EDGEevo VAMOS DL: 473 kbps DL: 1.9 Mbps Double SpeechGPRS UL: 473 kbps UL: 947 kbps Capacity UMTS HSDPA, 5 MHz HSPA+, R7 HSPA+, R8 HSPA+, R9 HSPA+, R10 DL: 2.0 Mbps DL: 14.4 Mbps DL: 28.0 Mbps DL: 42.0 Mbps DL: 84 Mbps DL: 84 Mbps UL: 2.0 Mbps UL: 2.0 Mbps UL: 11.5 Mbps UL: 11.5 Mbps UL: 23 Mbps UL: 23 Mbps HSPA, 5 MHz DL: 14.4 Mbps UL: 5.76 Mbps LTE (4x4), R8+R9, 20MHz LTE-Advanced R10 DL: 300 Mbps DL: 1 Gbps (low mobility) UL: 75 Mbps UL: 500 Mbps 1xEV-DO, Rev. 0 1xEV-DO, Rev. A 1xEV-DO, Rev. B cdma DO-Advanced 1.25 MHz 1.25 MHz 5.0 MHz DL: 32 Mbps and beyond 2000 DL: 2.4 Mbps DL: 3.1 Mbps DL: 14.7 Mbps UL: 12.4 Mbps and beyond UL: 153 kbps UL: 1.8 Mbps UL: 4.9 Mbps Fixed WiMAX Mobile WiMAX, 802.16e Advanced Mobile scalable bandwidth Up to 20 MHz WiMAX, 802.16m 1.25 … 28 MHz DL: 75 Mbps (2x2) DL: up to 1 Gbps (low mobility) typical up to 15 Mbps UL: 28 Mbps (1x2) UL: up to 100 Mbps November 2012 | LTE Introduction | 2
  • Why LTE?Ensuring Long Term Competitiveness of UMTS l LTE is the next UMTS evolution step after HSPA and HSPA+. l LTE is also referred to as EUTRA(N) = Evolved UMTS Terrestrial Radio Access (Network). l Main targets of LTE: l Peak data rates of 100 Mbps (downlink) and 50 Mbps (uplink) l Scaleable bandwidths up to 20 MHz l Reduced latency l Cost efficiency l Operation in paired (FDD) and unpaired (TDD) spectrum November 2012 | LTE Introduction | 3
  • Peak data rates and real average throughput (UL) 100 58 11,5 15 10 5,76Data rate in Mbps 5 2 2 1,8 2 0,947 1 0,473 0,7 0,5 0,174 0,153 0,2 0,1 0,1 0,1 0,1 0,03 0,01 GPRS EDGE 1xRTT WCDMA E-EDGE 1xEV-DO 1xEV-DO HSPA HSPA+ LTE 2x2 (Rel. 97) (Rel. 4) (Rel. 99/4) (Rel. 7) Rev. 0 Rev. A (Rel. 5/6) (Rel. 7) (Rel. 8) Technology max. peak UL data rate [Mbps] max. avg. UL throughput [Mbps] November 2012 | LTE Introduction | 4
  • Comparison of network latency by technology 800 158 160 710 700 140 600 120 3G / 3.5G / 3.9G latency2G / 2.5G latency 500 100 85 400 80 320 70 300 60 46 190 200 40 100 20 30 0 0 GPRS EDGE WCDMA HSDPA HSUPA E-EDGE HSPA+ LTE (Rel. 97) (Rel. 4) (Rel. 99/4) (Rel. 5) (Rel. 6) (Rel. 7) (Rel. 7) (Rel. 8) Technology Total UE Air interface Node B Iub RNC Iu + core Internet November 2012 | LTE Introduction | 5
  • Round Trip Time, RTT •ACK/NACK generation in RNC MSC TTI Iub/Iur Iu ~10msec Serving SGSN RNC Node B TTI =1msec MME/SAE Gateway eNode B •ACK/NACK generation in node B November 2012 | LTE Introduction | 6
  • Major technical challenges in LTE New radio transmission FDD and schemes (OFDMA / SC-FDMA) TDD mode MIMO multiple antenna Throughput / data rate schemes requirements Timing requirements Multi-RAT requirements (1 ms transm.time interval) (GSM/EDGE, UMTS, CDMA) Scheduling (shared channels, System Architecture HARQ, adaptive modulation) Evolution (SAE) November 2012 | LTE Introduction | 7
  • Introduction to UMTS LTE: Key parametersFrequency UMTS FDD bands and UMTS TDD bandsRange 1.4 MHz 3 MHz 5 MHz 10 MHz 15 MHz 20 MHz Channel bandwidth, 1 Resource 6 15 25 50 75 100 Block=180 kHz Resource Resource Resource Resource Resource Resource Blocks Blocks Blocks Blocks Blocks BlocksModulation Downlink: QPSK, 16QAM, 64QAMSchemes Uplink: QPSK, 16QAM, 64QAM (optional for handset) Downlink: OFDMA (Orthogonal Frequency Division Multiple Access)Multiple Access Uplink: SC-FDMA (Single Carrier Frequency Division Multiple Access) Downlink: Wide choice of MIMO configuration options for transmit diversity, spatialMIMO multiplexing, and cyclic delay diversity (max. 4 antennas at base station and handset)technology Uplink: Multi user collaborative MIMO Downlink: 150 Mbps (UE category 4, 2x2 MIMO, 20 MHz)Peak Data Rate 300 Mbps (UE category 5, 4x4 MIMO, 20 MHz) Uplink: 75 Mbps (20 MHz) November 2012 | LTE Introduction | 8
  • LTE/LTE-A Frequency Bands (FDD) E-UTRA Uplink (UL) operating band Downlink (DL) operating band Operating BS receive UE transmit BS transmit UE receive Duplex Mode Band FUL_low – FUL_high FDL_low – FDL_high 1 1920 MHz – 1980 MHz 2110 MHz – 2170 MHz FDD 2 1850 MHz – 1910 MHz 1930 MHz – 1990 MHz FDD 3 1710 MHz – 1785 MHz 1805 MHz – 1880 MHz FDD 4 1710 MHz – 1755 MHz 2110 MHz – 2155 MHz FDD 5 824 MHz – 849 MHz 869 MHz – 894MHz FDD 6 830 MHz – 840 MHz 875 MHz – 885 MHz FDD 7 2500 MHz – 2570 MHz 2620 MHz – 2690 MHz FDD 8 880 MHz – 915 MHz 925 MHz – 960 MHz FDD 9 1749.9 MHz – 1784.9 MHz 1844.9 MHz – 1879.9 MHz FDD 10 1710 MHz – 1770 MHz 2110 MHz – 2170 MHz FDD 11 1427.9 MHz – 1452.9 MHz 1475.9 MHz – 1500.9 MHz FDD 12 698 MHz – 716 MHz 728 MHz – 746 MHz FDD 13 777 MHz – 787 MHz 746 MHz – 756 MHz FDD 14 788 MHz – 798 MHz 758 MHz – 768 MHz FDD 17 704 MHz – 716 MHz 734 MHz – 746 MHz FDD 18 815 MHz – 830 MHz 860 MHz – 875 MHz FDD 19 830 MHz – 845 MHz 875 MHz – 890 MHz FDD 20 832 MHz - 862 MHz 791 MHz - 821 MHz FDD 21 1447.9 MHz - 1462.9 MHz 1495.9 MHz - 1510.9 MHz FDD 22 3410 MHz - 3500 MHz 3510 MHz - 3600 MHz FDD November 2012 | LTE Introduction | 9
  • LTE/LTE-A Frequency Bands (TDD) Uplink (UL) operating band Downlink (DL) operating band E-UTRA BS receive UE transmit BS transmit UE receive Operating Duplex Mode Band FUL_low – FUL_high FDL_low – FDL_high 33 1900 MHz – 1920 MHz 1900 MHz – 1920 MHz TDD 34 2010 MHz – 2025 MHz 2010 MHz – 2025 MHz TDD 35 1850 MHz – 1910 MHz 1850 MHz – 1910 MHz TDD 36 1930 MHz – 1990 MHz 1930 MHz – 1990 MHz TDD 37 1910 MHz – 1930 MHz 1910 MHz – 1930 MHz TDD 38 2570 MHz – 2620 MHz 2570 MHz – 2620 MHz TDD 39 1880 MHz – 1920 MHz 1880 MHz – 1920 MHz TDD 40 2300 MHz – 2400 MHz 2300 MHz – 2400 MHz TDD 3400 MHz – 3400 MHz – 41 TDD 3600MHz 3600MHz November 2012 | LTE Introduction | 10
  • Orthogonal Frequency Division Multiple Accessl OFDM is the modulation scheme for LTE in downlink and uplink (as reference)l Some technical explanation about our physical base: radio link aspects November 2012 | LTE Introduction | 11
  • What does it mean to use the radio channel? Using the radio channel means to deal with aspects like: C A D B Transmitter Receiver MPPTime variant channel Doppler effectFrequency selectivity attenuation November 2012 | LTE Introduction | 12
  • Still the same “mobile” radio problem:Time variant multipath propagation A: free space A: free space B: reflection B: reflection C C: diffraction C: diffraction A D: scattering D: scattering D B Transmitter ReceiverMultipath Propagation reflection: object is largeand Doppler shift compared to wavelength scattering: object is small or its surface irregular November 2012 | LTE Introduction | 13
  • Multipath channel impulse responseThe CIR consists of L resolvable propagation paths L 1 h  , t    ai  t  e     i  ji  t  i 0 path attenuation path phase path delay |h|²  delay spread November 2012 | LTE Introduction | 14
  • Radio Channel – different aspects to discuss Bandwidth or Wideband Narrowband Symbol duration or t t Short symbol Long symbol duration durationChannel estimation: Frequency?Pilot mapping Time? frequency distance of pilots? Repetition rate of pilots? November 2012 | LTE Introduction | 15
  • Frequency selectivity - Coherence Bandwidth Here: substitute with single power Scalar factor = 1-tap Frequency selectivity How to combat channel influence? f Narrowband = equalizer Can be 1 - tap Wideband = equalizerHere: find Must be frequency selectiveMath. Equationfor this curve November 2012 | LTE Introduction | 16
  • Time-Invariant Channel: Scenario Fixed ScattererISI: Inter Symbol Interference: Happens, when Delay spread > Symbol time Successive Fixed Receiver symbols Transmitter will interfere Channel Impulse Response, CIR Transmitter Receiver collision Signal Signal t t Delay Delay spread →time dispersive November 2012 | LTE Introduction | 17
  • Motivation: Single Carrier versus Multi Carrier TSC |H(f)| f Source: Kammeyer; Nachrichtenübertragung; 3. Auflage 1 B TSC B t |h(t)| t l Time Domain l Delay spread > Symboltime TSC → Inter-Symbol-Interference (ISI) → equalization effort l Frequency Domain l Coherence Bandwidth Bc < Systembandwidth B → Frequency Selective Fading → equalization effort November 2012 | LTE Introduction | 18
  • Motivation: Single Carrier versus Multi Carrier TSC |H(f)| f Source: Kammeyer; Nachrichtenübertragung; 3. Auflage 1 B B TSC t |h(t)| f t |H(f)| B 1 f   B N TMC t TMC  N  TSC November 2012 | LTE Introduction | 19
  • What is OFDM? Single carrier transmission, e.g. WCDMA Broadband, e.g. 5MHz for WCDMAOrthogonalFrequencyDivisionMultiplex Several 100 subcarriers, with x kHz spacing November 2012 | LTE Introduction | 20
  • Idea: Wide/Narrow band conversion ƒ … S/P … …H(ƒ) t / Tb t / Ts h(τ) h(τ) „Channel Memory“ τ τ One high rate signal: N low rate signals: Frequency selective fading Frequency flat fading November 2012 | LTE Introduction | 21
  • OFDM signal generation 00 11 10 10 01 01 11 01 …. e.g. QPSKh*(sinjwt + cosjwt) h*(sinjwt + cosjwt) => Σ h * (sin.. + cos…) Frequency time OFDM symbol duration Δt 2012 | November LTE Introduction | 22
  • COFDM Mapper X + XDatawith OFDMFEC Σ ..... symboloverhead Mapper X + X November 2012 | LTE Introduction | 23
  • Fourier Transform, Discrete FT Fourier Transform  H ( f )   h(t )e 2 j ft dt ;   h(t )   H ( f )e  2 j ft df ;  Discrete Fourier Transform (DFT) N 1 N 1 N 1 n n H n   hk e 2 j k n / N   hk cos(2  k )  j  hk sin(2  k ); k 0 k 0 N k 0 N N 1  2 j k n 1 hk  N H e n 0 n N ; November 2012 | LTE Introduction | 24
  • OFDM Implementation with FFT(Fast Fourier Transformation)Transmitter Channel d(0) Map IDFT NFFT d(1) P/S S/Pb (k ) Map . s(n) . . d(FFT-1) Map h(n)Receiver d(0) Demap n(n) DFT NFFT d(1) P/Sˆ k S/Pb( ) Demap . r(n) . . d(FFT-1) Demap November 2012 | LTE Introduction | 25
  • Inter-Carrier-Interference (ICI) 10 SMC  f  0 -10 -20  -30 xx S -40 -50 -60 -70 -1 -0.5 0 0.5 1   f-2 f-1 f0 f1 f2 f Problem of MC - FDM ICI Overlapp of neighbouring subcarriers → Inter Carrier Interference (ICI). Solution “Special” transmit gs(t) and receive filter gr(t) and frequencies fk allows orthogonal subcarrier → Orthogonal Frequency Division Multiplex (OFDM) November 2012 | LTE Introduction | 26
  • Rectangular Pulse A(f) Convolution sin(x)/x t f Δt Δf time frequency November 2012 | LTE Introduction | 27
  • Orthogonality Orthogonality condition: Δf = 1/Δt Δf November 2012 | LTE Introduction | 28
  • ISI and ICI due to channel Symbol l-1 l l+1  h  n n Receiver DFT Window Delay spread fade in (ISI) fade out (ISI) November 2012 | LTE Introduction | 29
  • ISI and ICI: Guard Intervall Symbol l-1 l l+1  h  n TG  Delay Spread n Receiver DFT Window Delay spread Guard Intervall guarantees the supression of ISI! November 2012 | LTE Introduction | 30
  • Guard Intervall as Cyclic Prefix Cyclic Prefix Symbol l-1 l l+1  h  n TG  Delay Spread n Receiver DFT Window Delay spread Cyclic Prefix guarantees the supression of ISI and ICI! November 2012 | LTE Introduction | 31
  • Synchronisation Cyclic Prefix OFDM Symbol : l  1 l l 1 CP CP CP CP Metric - Search window ~ n November 2012 | LTE Introduction | 32
  • DL CP-OFDM signal generation chain l OFDM signal generation is based on Inverse Fast Fourier Transform (IFFT) operation on transmitter side: Data QAM N Useful 1:N OFDM Cyclic prefixsource Modulator symbol IFFT N:1 OFDM symbols insertion streams symbols Frequency Domain Time Domain l On receiver side, an FFT operation will be used. November 2012 | LTE Introduction | 33
  • OFDM: Pros and Cons Pros:  scalable data rate  efficient use of the available bandwidth  robust against fading  1-tap equalization in frequency domain Cons:  high crest factor or PAPR. Peak to average power ratio  very sensitive to phase noise, frequency- and clock-offset  guard intervals necessary (ISI, ICI) → reduced data rate November 2012 | LTE Introduction | 34
  • MIMO =Multiple Input Multiple Output Antennas November 2012 | LTE Introduction | 35
  • MIMO is defined by the number of Rx / Tx Antennasand not by the Mode which is supported Mode1 1 SISO Typical todays wireless Communication System Single Input Single Output Transmit Diversity1 1 MISO l Maximum Ratio Combining (MRC) l Matrix A also known as STCM Multiple Input Single Output l Space Time / Frequency Coding (STC / SFC) Receive Diversity 1 1 SIMO l Maximum Ratio Combining (MRC) Single Input Multiple Output Receive / Transmit Diversity M Spatial Multiplexing (SM) also known as: l Space Division Multiplex (SDM) l True MIMO 1 1 MIMO l Single User MIMO (SU-MIMO) Multiple Input Multiple Output l Matrix B M M Space Division Multiple Access (SDMA) also known as: l Multi User MIMO (MU MIMO) l Virtual MIMO Definition is seen from Channel l Collaborative MIMO Multiple In = Multiple Transmit Antennas Beamforming November 2012 | LTE Introduction | 36
  • MIMO modes in LTE -Spatial Multiplexing-Tx diversity -Multi-User MIMO-Beamforming-Rx diversity Increased Increased Throughput per Throughput at Better S/N UE Node B November 2012 | LTE Introduction | 37
  • RX DiversityMaximum Ratio Combining depends on different fading of thetwo received signals. In other words decorrelated fading channels November 2012 | LTE Introduction | 38
  • TX Diversity: Space Time Coding Fading on the air interface data The same signal is transmitted at differnet antennas space Aim: increase of S/N ratio  increase of throughput  s1  s2  *S2   *  Alamouti Coding = diversity gain time approaches  s2 s1  RX diversity gain with MRRC! Alamouti Coding -> benefit for mobile communications November 2012 | LTE Introduction | 39
  • MIMO Spatial Multiplexing C=B*T*ld(1+S/N) SISO: Single Input Single OutputHigher capacity without additional spectrum! MIMO: S C   T  B  ld (1  ) ? min( N T , N R ) i i i 1 N Multiple Input i Multiple Output Increasing capacity per cell November 2012 | LTE Introduction | 40
  • The MIMO promisel Channel capacity grows linearly with antennas  Max Capacity ~ min(NTX, NRX)l Assumptions  l Perfect channel knowledge l Spatially uncorrelated fadingl Reality  l Imperfect channel knowledge l Correlation ≠ 0 and rather unknown November 2012 | LTE Introduction | 41
  • Spatial Multiplexing Coding Fading on the air interface data data Throughput: <200% 200% 100% Spatial Multiplexing: We increase the throughput but we also increase the interference! November 2012 | LTE Introduction | 42
  • Introduction – Channel Model II Correlation of propagation h11 pathes h21 s1 r1 hMR1 h12 s2 h22 r2 estimates Transmitter hMR2 Receiver h1MT h2MT NTx NRx sNTx hMRMT rNRx antennas antennas s H r Rank indicator Capacity ~ min(NTX, NRX) → max. possible rank! But effective rank depends on channel, i.e. the correlation situation of H November 2012 | LTE Introduction | 43
  • Spatial Multiplexing prerequisitesDecorrelation is achieved by:l Decorrelated data content on each spatial stream difficultl Large antenna spacing Channel conditionl Environment with a lot of scatters near the antenna (e.g. MS or indoor operation, but not BS) Technicall Precoding assist But, also possible that decorrelationl Cyclic Delay Diversity is not given November 2012 | LTE Introduction | 44
  • MIMO: channel interference + precodingMIMO channel models: different ways to combat against channel impact: I.: Receiver cancels impact of channel II.: Precoding by using codebook. Transmitter assists receiver in cancellation of channel impact III.: Precoding at transmitter side to cancel channel impact November 2012 | LTE Introduction | 45
  • MIMO: Principle of linear equalizing R = S*H + nTransmitter will send reference signals or pilot sequenceto enable receiver to estimate H. n H-1 Rx s r ^ r Tx H LE The receiver multiplies the signal r with the Hermetian conjugate complex of the transmitting function to eliminate the channel influence. November 2012 | LTE Introduction | 46
  • Linear equalization – compute power increase h11 H = h11 SISO: Equalizer has to estimate 1 channel h11 h12 h11 h12 H= h21 h22 h21 h22 2x2 MIMO: Equalizer has to estimate 4 channels November 2012 | LTE Introduction | 47
  • transmission – reception model noise s + r A H R transmitter channel receiver •Modulation, •detection, •Power •estimation •„precoding“, •Eliminating channel •etc. Linear equalization impact at receiver is not •etc. very efficient, i.e. noise can not be cancelled November 2012 | LTE Introduction | 48
  • MIMO – work shift to transmitter Channel ReceiverTransmitter November 2012 | LTE Introduction | 49
  • MIMO Precoding in LTE (DL)Spatial multiplexing – Code book for precoding Code book for 2 Tx: Codebook Number of layers  index 1 2 Additional multiplication of the 1  1 1 0 0 0      2 0 1  layer symbols with codebook 0  1 1 1  entry 1 1      2 1 1 1 1 1 1 1  2    2 1 2  j  j 1 1 3   - 2 1 1 1  4   - 2  j 1 1 5   - 2  j  November 2012 | LTE Introduction | 50
  • MIMO precoding precodingAnt1Ant2 t +  1 2 1 ∑ t + 1 precoding -1 1 ∑=0 t t November 2012 | LTE Introduction | 51
  • MIMO – codebook based precodingPrecodingcodebook noise s + r A H R transmitter channel receiver Precoding Matrix Identifier, PMICodebook based precoding createssome kind of „beamforming light“ November 2012 | LTE Introduction | 52
  • MIMO: avoid inter-channel interference – future outlooke.g. linear precoding: V1,k Y=H*F*S+V S Link adaptation + Transmitter H Space time F receiver xk + yk VM,k Feedback about H Idea: F adapts transmitted signal to current channel conditions November 2012 | LTE Introduction | 53
  • MAS: „Dirty Paper“ Coding – future outlookl Multiple Antenna Signal Processing: „Known Interference“ l Is like NO interference l Analogy to writing on „dirty paper“ by changing ink color accordingly „Known „Known „Known „Known Interference Interference Interference Interference is No is No is No is No Interference“ Interference“ Interference“ Interference“ November 2012 | LTE Introduction | 54
  • Spatial Multiplexing Codeword Fading on the air interface data Codeword data Spatial Multiplexing: We like to distinguish the 2 useful Propagation passes: How to do that? => one idea is SVD November 2012 | LTE Introduction | 55
  • Idea of Singular Value Decomposition s1 MIMO r1 know r=Hs+n s2 r2 channel H Singular Value Decomposition ~ s1 ~ r1 SISO wanted ~ ~ s2 r2 ~ ~ ~ r=Ds+n channel D November 2012 | LTE Introduction | 56
  • Singular Value Decomposition (SVD) r=Hs+n H = U Σ (V*)T U = [u1,...,un] eigenvectors of (H*)T H V = [v1,...,vm] eigenvectors of H (H*)T  1 0 0  0  i eigenvalues of (H*)T H  0 0   2  0 0 3  singular values  i  i  0  0  ~ = (U*)T r r ~ ~= Σ s + n r ~ ~ s = (V*)T s ~ = (U*)T n n November 2012 | LTE Introduction | 57
  • MIMO: Signal processing considerations MIMO transmission can be expressed as r = Hs+n which is, using SVD = UΣVHs+n n1s1 σ1 r1 V U Σ VH n2 UHs2 σ2 r2 Imagine we do the following: 1.) Precoding at the transmitter: Instead of transmitting s, the transmitter sends s = V*s 2.) Signal processing at the receiver Multiply the received signal with UH, r = r*UHSo after signal processing the whole signal can be expressed as:r =UH*(UΣVHVs+n)=UHU Σ VHVs+UHn = Σs+UHn =InTnT =InTnT November 2012 | LTE Introduction | 58
  • MIMO: limited channel feedback Transmitter H Receiver n1 s1 σ1 r1 V U Σ VH n2 UH s2 σ2 r2 Idea 1: Rx sends feedback about full H to Tx. -> but too complex, -> big overhead -> sensitive to noise and quantization effects Idea 2: Tx does not need to know full H, only unitary matrix V -> define a set of unitary matrices (codebook) and find one matrix in the codebook that maximizes the capacity for the current channel H -> these unitary matrices from the codebook approximate the singular vector structure of the channel => Limited feedback is almost as good as ideal channel knowledge feedback November 2012 | LTE Introduction | 59
  • Cyclic Delay Diversity, CDD A2 A1 Amp litud D eTransmitter B Delay Spread Time Delay Multipath propagation precoding +  + precoding Time No multipath propagation Delay November 2012 | LTE Introduction | 60
  • „Open loop“ und „closed loop“ MIMO Open loop (No channel knowledge at transmitter) r  Hs  n Channel Status, CSI Rank indicator Closed loop (With channel knowledge at transmitter r  HWs  n Channel Status, CSI Rank indicatorAdaptive Precoding matrix („Pre-equalisation“)Feedback from receiver needed (closed loop) November 2012 | LTE Introduction | 61
  • MIMO transmission modes Transmission mode2 Transmission mode3 TX diversityTransmission mode1 Open-loop spatial SISO multiplexing 7 transmission Transmission mode4 Transmission mode7 Closed-loop spatial modes are SISO, port 5 multiplexing defined = beamforming in TDD Transmission mode6 Transmission mode5 Closed-loop Multi-User MIMO spatial multiplexing, using 1 layerTransmission mode is given by higher layer IE: AntennaInfo November 2012 | LTE Introduction | 62
  • Beamforming Closed loop precoded Adaptive Beamforming beamforming•Classic way •Kind of MISO with channel knowledge at transmitter•Antenna weights to adjust beam •Precoding based on feedback•Directional characteristics •No specific antenna•Specific antenna array geometrie array geometrie•Dedicated pilots required •Common pilots are sufficient November 2012 | LTE Introduction | 63
  • Spatial multiplexing vs beamformingSpatial multiplexing increases throughput, but looses coverage November 2012 | LTE Introduction | 64
  • Spatial multiplexing vs beamforming Beamforming increases coverage November 2012 | LTE Introduction | 65
  • Basic OFDM parameter LTE 1 f  15 kHz  T Fs  N FFT  f N FFT Fs   3.84Mcps 256 f NFFT  2048 Coded symbol rate= R Sub-carrier CP S/P Mapping IFFT insertion N TX Data symbols Size-NFFT November 2012 | LTE Introduction | 66
  • LTE Downlink: Downlink slot and (sub)frame structure Symbol time, or number of symbols per time slot is not fixed One radio frame, Tf = 307200Ts=10 ms One slot, Tslot = 15360Ts = 0.5 ms #0 #1 #2 #3 #18 #19 One subframeWe talk about 1 slot, but the minimum resource is 1 subframe = 2 slots !!!!! Ts  1 15000  2048 Ts = 32.522 ns November 2012 | LTE Introduction | 67
  • Resource block definition 1 slot = 0,5msecResource block=6 or 7 symbolsIn 12 subcarriers 12 subcarriers Resource element DL UL N symb or N symb 6 or 7, Depending on cyclic prefix November 2012 | LTE Introduction | 68
  • LTE DownlinkOFDMA time-frequency multiplexing frequency QPSK, 16QAM or 64QAM modulation UE4 1 resource block = 180 kHz = 12 subcarriers UE5 UE3 UE2 UE6 Subcarrier spacing = 15 kHz time UE1 1 subframe =*TTI = transmission time interval 1 slot = 0.5 ms = 1 ms= 1 TTI*=** For normal cyclic prefix duration 7 OFDM symbols** 1 resource block pair November 2012 | LTE Introduction | 69
  • LTE: new physical channels for data and control Physical Control Format Indicator Channel PCFICH: Indicates Format of PDCCH Physical Downlink Control Channel PDCCH: Downlink and uplink scheduling decisions Physical Downlink Shared Channel PDSCH: Downlink data Physical Hybrid ARQ Indicator Channel PHICH: ACK/NACK for uplink packets Physical Uplink Shared Channel PUSCH: Uplink data Physical Uplink Control Channel PUCCH: ACK/NACK for downlink packets, scheduling requests, channel quality info November 2012 | LTE Introduction | 70
  • LTE Downlink: FDD channel mapping example Subcarrier #0 RB November 2012 | LTE Introduction | 71
  • LTE Downlink: baseband signal generationcode words layers antenna ports Modulation OFDM OFDM signal Scrambling Mapper Mapper generation Layer Precoding Mapper Modulation OFDM OFDM signal Scrambling Mapper Mapper generation 1 stream = several Avoid QPSK For MIMO Weighting 1 OFDM subcarriers, constant 16 QAM Split into data symbol per based onsequences 64 QAM Several streams for stream Physical streams if MIMO ressource needed blocks November 2012 | LTE Introduction | 72
  • Adaptive modulation and coding Transportation block size User data FECFlexible ratio between data and FEC = adaptive coding November 2012 | LTE Introduction | 73
  • Channel Coding Performance November 2012 | LTE Introduction | 74
  • Automatic repeat request, latency aspects •Transport block size = amount of data bits (excluding redundancy!) •TTI, Transmit Time Interval = time duration for transmitting 1 transport block Transport block Round Trip Time ACK/NACK Network UE Immediate acknowledged or non-acknowledged feedback of data transmission November 2012 | LTE Introduction | 75
  • HARQ principle: Multitasking Δt = Round trip timeTx Data Data Data Data Data Data Data Data Data Data ACK/NACK Demodulate, decode, descramble, Rx FFT operation, check CRC, etc. process ACK/NACK Processing time for receiver Rx Demodulate, decode, descramble, process FFT operation, check CRC, etc. t Described as 1 HARQ process November 2012 | LTE Introduction | 76
  • LTE Round Trip Time RTT n+4 n+4 n+4 ACK/NACK PDCCH PHICH Downlink HARQ Data Data UL Uplinkt=0 t=1 t=2 t=3 t=4 t=5 t=6 t=7 t=8 t=9 t=0 t=1 t=2 t=3 t=4 t=5 1 frame = 10 subframes 8 HARQ processes RTT = 8 msec November 2012 | LTE Introduction | 77
  • HARQ principle: Soft combining 1st transmission with puncturing scheme P1 l T i is a e am l o h n e co i g 2nd transmission with puncturing scheme P2 l hi i n x m le f cha n l c ing Soft Combining = Σ of transmission 1 and 2 l Thi is an exam le of channel co ing Final decoding lThis is an example of channel coding November 2012 | LTE Introduction | 78
  • Hybrid ARQChase Combining = identical retransmission Turbo Encoder output (36 bits) Systematic Bits Parity 1 Parity 2 Transmitted Bit Rate Matching to 16 bits (Puncturing) Original Transmission Retransmission Systematic Bits Parity 1 Parity 2 Punctured Bit Chase Combining at receiver Systematic Bits Parity 1 Parity 2 November 2012 | LTE Introduction | 79
  • Hybrid ARQIncremental Redundancy Turbo Encoder output (36 bits) Systematic Bits Parity 1 Parity 2 Rate Matching to 16 bits (Puncturing) Original Transmission Retransmission Systematic Bits Parity 1 Parity 2 Punctured Bit Incremental Redundancy Combining at receiver Systematic Bits Parity 1 Parity 2 November 2012 | LTE Introduction | 80
  • LTE Physical Layer: SC-FDMA in uplinkSingle Carrier Frequency Division Multiple Access November 2012 | LTE Introduction | 81
  • LTE Uplink:How to generate an SC-FDMA signal in theory? Coded symbol rate= R Sub-carrier CP DFT Mapping IFFT insertion NTX symbols Size-NTX Size-NFFT LTE provides QPSK,16QAM, and 64QAM as uplink modulation schemes DFT is first applied to block of NTX modulated data symbols to transform them into frequency domain Sub-carrier mapping allows flexible allocation of signal to available sub-carriers IFFT and cyclic prefix (CP) insertion as in OFDM Each subcarrier carries a portion of superposed DFT spread data symbols Can also be seen as “pre-coded OFDM” or “DFT-spread OFDM” November 2012 | LTE Introduction | 82
  • LTE Uplink: How does the SC-FDMA signal look like? In principle similar to OFDMA, BUT:  In OFDMA, each sub-carrier only carries information related to one specific symbol  In SC-FDMA, each sub-carrier contains information of ALL transmitted symbols November 2012 | LTE Introduction | 83
  • LTE uplink SC-FDMA time-frequency multiplexing 1 resource block = 180 kHz = 12 subcarriers Subcarrier spacing = 15 kHz frequency UE1 UE2 UE3 1 slot = 0.5 ms = 7 SC-FDMA symbols**1 subframe =1 ms= 1 TTI* UE4 UE5 UE6 *TTI = transmission time interval ** For normal cyclic prefix duration time QPSK, 16QAM or 64QAM modulation November 2012 | LTE Introduction | 84
  • LTE Uplink: baseband signal generation UE specificScrambling code Modulation Transform Resource SC-FDMA Scrambling element mapper mapper precoder signal gen. Mapping on physical 1 stream = Discrete Ressource, several Avoid QPSK Fourier i.e. subcarriers, constant 16 QAM Transform subcarriers based onsequences 64 QAM not used for Physical (optional) reference ressource signals blocks November 2012 | LTE Introduction | 85
  • LTE evolution LTE Rel. 9 features LTE AdvancedNovember 2012 | LTE Introduction | 86
  • The LTE evolution Rel-9 eICIC enhancements Relaying In-device Rel-10 Diverse Data co-existence Application CoMP Rel-11 Relaying eICIC eMBMS enhancements SON enhancements MIMO 8x8 MIMO 4x4 Carrier Enhanced Aggregation SC-FDMA Public Warning Positioning System Home eNodeB Self Organizing eMBMS Networks DL UL Multi carrier / Dual Layer DL UL Multi-RAT Beamforming Base Stations LTE Release 8 FDD / TDD November 2012 | LTE Introduction | 87
  • What are antenna ports?l 3GPP TS 36.211(Downlink) “An antenna port is defined such that the channel over which a symbol on the antenna port is conveyed can be inferred from the channel over which another symbol on the same antenna port is conveyed.”l What does that mean?l The UE shall demodulate a received signal – which is transmitted over a certain antenna port – based on the channel estimation performed on the reference signals belonging to this (same) antenna port. November 2012 | LTE Introduction | 88
  • What are antenna ports?l Consequences of the definition l There is one sort of reference signal per antenna port l Whenever a new sort of reference signal is introduced by 3GPP (e.g. PRS), a new antenna port needs to be defined (e.g. Antenna Port 6)l 3GPP defines the following antenna port / reference signal combinations for downlink transmission: l Port 0-3: Cell-specific Reference Signals (CS-RS) l Port 4: MBSFN-RS l Port 5: UE-specific Reference Signals (DM-RS): single layer (TX mode 7) l Port 6: Positioning Reference Signals (PRS) l Port 7-8: UE-specific Reference Signals (DM-RS): dual layer (TX mode 8) l Port 7-14: UE specific Referene Signals for Rel. 10 l Port 15 – 22: CSI specific reference signals, channel status info in Rel. 10 November 2012 | LTE Introduction | 89
  • What are antenna ports?l Mapping „Antenna Port“ to „Physical Antennas“ Antenna Port Physical Antennas 1 AP0 PA0 AP1 1 W5,0 AP2 1 PA1 W5,1 AP3 1 PA2 AP4 … W5,2 W5,3 AP5 PA3 … AP6 AP7 … AP8 …The way the "logical" antenna ports are mapped to the "physical" TX antennas liescompletely in the responsibility of the base station. Theres no need for the base stationto tell the UE. November 2012 | LTE Introduction | 90
  • LTE antenna port definition Antenna ports are linked to the reference signals -> one example: Normal CP Cell Specific RS PA -RS PCFICH /PHICH /PDCCH PUSCH or No Transmission UE in connected mode, scansUE in idle mode, scans for Positioning RS on antenna port 6Antenna port 0, cell specific RS to locate its position November 2012 | LTE Introduction | 91
  • Multimedia Broadcast Messaging Services, MBMS Broadcast: Unicast: Public info for Private info for dedicated user everybody Multicast: Common info for User after authentication November 2012 | LTE Introduction | 92
  • LTE MBMS architecture November 2012 | LTE Introduction | 93
  • MBMS in LTE MBMS MME GW | M3 MBMS GW: MBMS Gateway MCE: Multi-Cell/Multicast Coordination Entity M1 | MCE M1: user plane interface M2: E-UTRAN internal control plane interface M2 M3: control plane interface between E-UTRAN and EPC | eNB Logical architecture for MBMS November 2012 | LTE Introduction | 94
  • MBSFN – MBMS Single Frequency NetworkMobile communication network Single Frequency Networkeach eNode B sends individual each eNode B sends identicalsignals signals November 2012 | LTE Introduction | 95
  • MBSFN If network is synchronised, Signals in downlink can be combined November 2012 | LTE Introduction | 96
  • evolved Multimedia Broadcast Multicast Services Multimedia Broadcast Single Frequency Network (MBSFN) area l Useful if a significant number of users want to consume the same data content at the same time in the same area! l Same content is transmitted in a specific area is known as MBSFN area. l Each MBSFN area has an own identity (mbsfn-AreaId 0…255) and can consists of multiple cells; a cell can belong to more than one MBSFN area. l MBSFN areas do not change dynamically over time. MBSFN area 0 MBSFN area 255 11 3 8 13 MBSFN reserved cell. 1 6 12 15 A cell within the MBSFNarea, that does not support 4 9 14 MBMS transmission. 2 7 13 5 10 A cell can belong to MBSFN area 1 more than one MBSFN area; in total up to 8. November 2012 | LTE Introduction | 97
  • eMBMSDownlink Channelsl Downlink channels related to MBMS l MCCH Multicast Control Channel l MTCH Multicast Traffic Channel l MCH Multicast Channel l PMCH Physical Multicast Channell MCH is transmitted over MBSFN in specific subrames on physical layerl MCH is a downlink only channel (no HARQ, no RLC repetitions) l Higher Layer Forward Error Correction (see TS26.346)l Different services (MTCHs and MCCH) can be multiplexed November 2012 | LTE Introduction | 98
  • eMBMS channel mapping Subframes 0,4,5 and 9 are not MBMS, because Of paging occasion can occur here Subframes 0 and 5 are not MBMS, because of PBCH and Sync Channels November 2012 | LTE Introduction | 99
  • eMBMS allocation based on SIB2 information 011010 Reminder: Subframes 0,4,5, and 9 Are non-MBMS November 2012 | LTE Introduction | 100
  • eMBMS: MCCH position according to SIB13 November 2012 | LTE Introduction | 101
  • LTE Release 9Dual-layer beamformingl 3GPP Rel-8 – Transmission Mode 7 = beamforming without UE feedback, using UE-specific reference signal pattern, l Estimate the position of the UE (Direction of Arrival, DoA), l Pre-code digital baseband to direct beam at direction of arrival, l BUT single-layer beamforming, only one codeword (TB),l 3GPP Rel-9 – Transmission Mode 8 = beamforming with or without UE feedback (PMI/RI) using UE-specific reference signal pattern, but dual-layer, l Mandatory for TDD, optional for FDD, l 2 (new) reference signal pattern for two new antenna ports 7 and 8, l New DCI format 2B to schedule transmission mode 8, l Performance test in 3GPP TS 36.521 Part 1 (Rel-9) are adopted to support testing of transmission mode 8. November 2012 | LTE Introduction | 102
  • LTE Release 9Dual-layer beamforming – Reference Symbol Detailsl Cell specific antenna port 0 and antenna port 1 reference symbols Antenna Port 0 Antenna Port 1l UE specific antenna port 7 and antenna port 8 reference symbols Antenna Port 7 Antenna Port 8 November 2012 | LTE Introduction | 103
  • 2 layer beamforming throughput Spatial multiplexing: increase throughput but less coverage 1 layer beamforming: increase coverage SISO: coverage and throughput, no increase 2 layer beamforming Increases throughput and coverage coverageSpatial multiplexing increases throughput, but looses coverage November 2012 | LTE Introduction | 104
  • Location based servicesl Location Based Services“l Products and services which need location informationl Future Trend: Augmented Reality November 2012 | LTE Introduction | 105
  • Where is Waldo?November 2012 | LTE Introduction | 106
  • Location based servicesThe idea is not new, … so what to discuss?Satellite based services Location controller Network based services Who will do the measurements? The UE or the network? = „assisted“ Who will do the calculation? The UE or the network? = „based“ So what is new? Several ideas are defined and hybrid mode is possible as well, Various methods can be combined. November 2012 | LTE Introduction | 107
  • E-UTRA supported positioning methods November 2012 | LTE Introduction | 108
  • E-UTRA supported positioning network architecture Control plane and user plane signaling LCS4) Client S1-U Serving S5 Packet Lup SUPL / LPP Gateway Gateway SLP1) (S-GW) (P-GW) LCS Server (LS) SLs LPPa LPP Mobile Management E-SMLC2) GMLC3) S1-MME SLs Entity (MME)LTE-capable device LTE base stationUser Equipment, UE eNodeB (eNB) (LCS Target) Secure User Plane Location positioning SUPL= user plane protocol LPP = signaling control plane 1) SLP – SUPL Location Platform, SUPL – Secure User Plane Location 2) E-SMLC – Evolved Serving Mobile Location Center signaling 3) GMLC – Gateway Mobile Location Center 4) LCS – Location Service 5) 3GPP TS 36.455 LTE Positioning Protocol Annex (LPPa) 6) 3GPP TS 36.355 LTE Positioning Protocol (LPP) November 2012 | LTE Introduction | 109
  • E-UTRAN UE Positioning Architecturel In contrast to GERAN and UTRAN, the E-UTRAN positioning capabilities are intended to be forward compatible to other access types (e.g. WLAN) and other positioning methods (e.g. RAT uplink measurements).l Supports user plane solutions, e.g. OMA SUPL 2.0 UE = User Equipment SUPL* = Secure User Plane Location OMA* = Open Mobile Alliance SET = SUPL enabled terminal SLP = SUPL locaiton platform E-SMLC = Evolved Serving Mobile Location Center MME = Mobility Management Entity RAT = Radio Access Technology *www.openmobilealliance.org/technical/release_program/supl_v2_0.aspx November 2012 | LTE Introduction | 110 Source: 3GPP TS 36.305
  • Global Navigation Satellite Systemsl GNSS – Global Navigation Satellite Systems; autonomous systems: l GNSS are designed for l GPS – USA 1995. continuous l GLONASS – Russia, 2012. reception, outdoors. l Gallileo – Europe, target 201?. l Challenging environments: l Compass (Beidou) – China, under urban, indoors, changing development, target 2015. locations. l IRNSS – India, planning process. E5a E1 L5 L5b L2 G2 E6 L1 G1 1164 1215 1237 1260 1300 1559 1591 f [MHz] 1563 1587 1610 GALLILEO GPS GLONASS Signal fCarrier [MHz] Signal fCarrier [MHz] Signal fCarrier [MHz] 1602±k*0,562 E1 1575,420 L1C/A 1575,420 G1 5 1246±k*0,562 E6 1278,750 L1C 1575,420 G2 5 E5 1191,795 L2C 1227,600 k = -7 … 13 E5a 1176,450 L5 1176,450 http://www.hindawi.com/journals/ijno/2010/812945/ E5b 1207,140 November 2012 | LTE Introduction | 111
  • LTE Positioning Protocol (LPP) 3GPP TS 36.355 LPP position methods - A-GNSS Assisted Global Navigation Satellite System - E-CID Enhanced Cell ID LTE radio - OTDOA Observed time differerence of arrival signal *GNSS and LTE radio signalseNB Measurements based on reference sources* Target LPP Location Device Server Assistance data LPP over RRC UE Control plane solution E-SMLC Enhanced Serving Mobile Location Center LPP over SUPLSUPL enabled Terminal SET User plane solution SLP SUPL location platform November 2012 | LTE Introduction | 112
  • GNSS positioning methods supportedl Autonomeous GNSSl Assisted GNSS (A-GNSS) l The network assists the UE GNSS receiver to improve the performance in several aspects: – Reduce UE GNSS start-up and acquisition times – Increase UE GNSS sensitivity – Allow UE to consume less handset power l UE Assisted – UE transmits GNSS measurement results to E-SMLC where the position calculation takes place l UE Based – UE performs GNSS measurements and position calculation, suppported by data … – … assisting the measurements, e.g. with reference time, visible satellite list etc. – … providing means for position calculation, e.g. reference position, satellite ephemeris, etc. November 2012 | LTE Introduction | 113 Source: 3GPP TS 36.305
  • GNSS band allocations E5a E1 L5 E5b L2 G2 E6 L1 G1 f/MHz1164 1215 1237 1260 1300 1559 1563 1587 1591 1610 November 2012 | LTE Introduction | 114
  • GPS and GLONASS satellite orbits GPS: 26 Satellites Orbital radius 26560 km GLONASS: 26 Satellites Orbital radius 25510 km November 2012 | LTE Introduction | 115
  • Why is GNSS not sufficent? Critical scenario Very critical scenario GPS Satellites visibility (Urban) l Global navigation satellite systems (GNSSs) have restricted performance in certain environments l Often less than four satellites visible: critical situation for GNSS positioning  support required (Assisted GNSS)  alternative required (Mobile radio positioning) Reference [DLR] November 2012 | LTE Introduction | 116
  • (A-)GNSS vs. mobile radio positioningmethods (A-)GNSS Mobile radio systems Low bandwidth (1-2 MHz) High bandwidth (up to 20 MHz for LTE) Very weak received signals Comparatively strong received signals One strong signal from the serving BS, Similar received power levels from all satellites strong interference situation Long synchronization sequences Short synchronization sequences Complete signal not a-priori known to Signal a-priori known due to low data rates support high data rates, only certain pilots Very accurate synchronization of the satellites Synchronization of the BSs not a-priori guaranteed by atomic clocks Line of sight (LOS) access as normal case Non line of sight (NLOS) access as normal case  not suitable for urban / indoor areas  suitable for urban / indoor areas 3-dimensional positioning 2-dimensional positioning November 2012 | LTE Introduction | 117
  • Measurements for positioningl UE-assisted measurements. l eNB-assisted measurements. l Reference Signal Received l eNB Rx – Tx time difference. Power l TADV – Timing Advance. (RSRP) and Reference Signal – For positioning Type 1 is of Received Quality (RSRQ). relevance. l RSTD – Reference Signal Time l AoA – Angle of Arrival. Difference. l UTDOA – Uplink Time Difference l UE Rx–Tx time difference. of Arrival. TADV (Timing Advance) = eNB Rx-Tx time difference + UE Rx-Tx time difference Neighbor cell j = (TeNB-RX – TeNB-TX) + (TUE-RX – TUE-TX) UL radio frame #i RSTD – Relative time difference between a subframe received from neighbor cell j and corresponding subframe from serving cell i: TSubframeRxj - TSubframeRxi DL radio frame #i UL radio frame #i DL radio frame #i Serving cell i eNB Rx-Tx time difference is defined UE Rx-Tx time difference is defined RSRP, RSRQ are as TeNB-RX – TeNB-TX, where TeNB-RX is the as TUE-RX – TUE-TX, where TUE-RX is the measured on reference received timing of uplink radio frame #ireceived timing of downlink radio frame signals of serving cell i and TeNB-TX the transmit timing of #i from the serving cell i and TUE-TX the downlink radio frame #i. transmit timing of uplink radio frame #i. Source: see TS 36.214 Physical Layer measurements for detailed definitions November 2012 | LTE Introduction | 118
  • Observed Time difference Observed Time Difference of Arrival OTDOA If network is synchronised, UE can measure time difference November 2012 | LTE Introduction | 119
  • Methods‘ overview CID E-CID (RSRP/TOA/TADV) E-CID (RSRP/TOA/TADV) [Trilateration] E-CID (AOA) [Triangulation] Downlink / Uplink (O/U-TDOA) [Multilateration] RF Pattern matching To be updated!! November 2012 | LTE Introduction | 120
  • Cell IDl Not new, other definition: Cell of Origin (COO). l UE position is estimated with the knowledge of the geographical coordinates of its serving eNB. l Position accuracy = One whole cell . November 2012 | LTE Introduction | 121
  • Enhanced-Cell ID (E-CID)l UE positioning compared to CID is specified more accurately using additional UE and/or E UTRAN radio measurements: l E-CID with distance from serving eNB  position accuracy: a circle. – Distance calculated by measuring RSRP / TOA / TADV (RTT). l E-CID with distances from 3 eNB-s  position accuracy: a point. – Distance calculated by measuring RSRP / TOA / TADV (RTT). l E-CID with Angels of Arrival  position accuracy: a point. – AOA are measured for at least 2, better 3 eNB‘s. RSRP – Reference Signal Received Power TOA – Time of Arrival November 2012 | LTE Introduction | 122 TADV – Timing Advance RTT – Round Trip Time
  • Angle of Arrival (AOA)l AoA = Estimated angle of a UE with respect to a reference direction (= geographical North), positive in a counter- clockwise direction, as seen from an eNB. l Determined at eNB antenna based on a received UL signal (SRS).l Measurement at eNB: l eNB uses antenna array to estimate direction i.e. Angle of Arrival (AOA). l The larger the array, the more accurate is the estimated AOA. l eNB reports AOA to LS. l Advantage: No synchronization between eNB‘s. l Drawback: costly antenna arrays. November 2012 | LTE Introduction | 123
  • OTDOA – Observed Time Difference ofArrivall UE position is estimated based on measuring TDOA of Positioning Reference Signals (PRS) embedded into overall DL signal received from different eNB’s. l Each TDOA measurement describes a hyperbola (line of constant difference 2a), the two focus points of which (F1, F2) are the two measured eNB-s (PRS sources), and along which the UE may be located. l UE’s position = intersection of hyperbolas for at least 3 pairs of eNB’s. November 2012 | LTE Introduction | 124
  • Positioning Reference Signals (PRS) for OTDOADefinitionl Cell-specific reference signals (CRS) are not sufficient for positioning, introduction of positioning reference signals (PRS) for antenna port 6. l SINR for synchronization and reference signals of neighboring cells needs to be at least -6 dB.l PRS is a pseudo-random QPSK sequence similar to CRS; PRS pattern: l Diagonal pattern with time varying frequency shift. l PRS mapped around CRS to avoid collisions; never overlaps with PDCCH; example shows CRS mapping for usage of 4 antenna ports. November 2012 | LTE Introduction | 125
  • Uplink (UTDOA) l UTDOA = Uplink Time Difference of Arrival l UE positioning estimated based on: – measuring TDOA of UL (SRS) signals received in different eNB-s – each TDOA measurement describes a hyperbola (line of constant difference 2a), the 2 focus points of which (F1, F2) are the two receiving eNB-s (SRS receiptors), and along which the UE may be located. – UE’s position = intersection of hyperbolas for at least three pairs of eNB-s (= 3 eNB-s) – knowledge of the geographical coordinates of the measured eNode Bs l Method as such not specified for LTE  Similarity to 3G assumed - eNB-s measure and report to eNB_Rx-Tx to LS -LS calculates UTDOA Location Server and estimates the UE position November 2012 | LTE Introduction | 126
  • IMT-Advanced Requirementsl A high degree of commonality of functionality worldwide while retaining the flexibility to support a wide range of services and applications in a cost efficient manner,l Compatibility of services within IMT and with fixed networks,l Capability of interworking with other radio access systems,l High quality mobile services,l User equipment suitable for worldwide use,l User-friendly applications, services and equipment,l Worldwide roaming capability; andl Enhanced peak data rates to support advanced services and applications, l 100 Mbit/s for high and l 1 Gbit/s for low mobility were established as targets for research, November 2012 | LTE Introduction | 127
  • Do you Remember?Targets of ITU IMT-2000 Program (1998) IMT-2000 The ITU vision of global wireless access in the 21st century Global Satellite Suburban Urban In-Building Picocell Microcell Macrocell Basic Terminal PDA Terminal Audio/Visual Terminall Flexible and global – Full coverage and mobility at 144 kbps .. 384 kbps – Hot spot coverage with limited mobility at 2 Mbps – Terrestrial based radio access technologiesl The IMT-2000 family of standards now supports four different multiple access technologies: l FDMA, TDMA, CDMA (WCDMA) and OFDMA (since 2007) November 2012 | LTE Introduction | 128
  • IMT Spectrum MHz MHzNext possible spectrumallocation at WRC 2015! MHz MHz November 2012 | LTE Introduction | 129
  • Expected IMT-Advanced candidates Long Term Evolution Ultra Mobile Broadband Advanced Mobile WiMAX Source: TTA‘s workshop for the future of IMT-Advanced technologies, June 2008 November 2012 | LTE Introduction | 130
  • IMT – International Mobile Communicationl IMT-2000 l Was the framework for the third Generation mobile communication systems, i.e. 3GPP-UMTS and 3GPP2-C2K l Focus was on high performance transmission schemes: Link Level Efficiency l Originally created to harmonize 3G mobile systems and to increase opportunities for worldwide interoperability, the IMT-2000 family of standards now supports four different access technologies, including OFDMA (WiMAX), FDMA, TDMA and CDMA (WCDMA).l IMT-Advanced l Basis of (really) broadband mobile communication l Focus on System Level Efficiency (e.g. cognitive network systems) l Vision 2010 – 2015 November 2012 | LTE Introduction | 131
  • LTE-AdvancedPossible technology features Relaying Wider bandwidth technology support Enhanced MIMO Cooperative schemes for DL and UL base stations Interference management Cognitive radio methods methods Radio network evolution Further enhanced MBMS November 2012 | LTE Introduction | 132
  • Bandwidth extension with Carrier aggregation November 2012 | LTE Introduction | 133
  • LTE-AdvancedCarrier Aggregation Component carrier CC Contiguous carrier aggregation Non-contiguous carrier aggregation November 2012 | LTE Introduction | 134
  • Aggregationl Contiguous l Intra-Bandl Non-Contiguous l Intra (Single) -Band l Inter (Multi) -Bandl Combination l Up to 5 Rel-8 CC and 100 MHz l Theoretically all CC-BW combinations possible (e.g. 5+10+20 etc) November 2012 | LTE Introduction | 135
  • Carrier aggregation (CA)General commentsl Two or more component carriers are aggregated in LTE-Advanced in order to support wider bandwidths up to 100 MHz. l Support for contiguous and non- Intra-band contiguous Frequency band A Frequency band B contiguous component carrier aggregation (intra-band) and inter-band carrier aggregation. Component Carrier (CC) l Different bandwidths per Intra-band non-contiguous Frequency band A Frequency band B component carrier (CC) are possible. l Each CC limited to a max. of 110 RB using the 3GPP Rel-8 numerology 2012 © by Rohde&Schwarz (max. 5 carriers, 20 MHz each). Inter-bandl Motivation. Frequency band A Frequency band B l Higher peak data rates to meet IMT-Advanced requirements. l NW operators: spectrum aggregation, enabling Heterogonous Networks. November 2012 | LTE Introduction | 136
  • Overviewl Carrier Aggregation (CA) enables to aggregate up to 5 different cells (component carriers CC), so that a maximum system bandwidth of 100 MHz can be supported (LTE-Advanced requirement). l Each CC = Rel-8 autonomous cell Cell 1 Cell 2 – Backwards compatibility l CC-Set is UE specific – Registration  Primary (P)CC UE1 UE4 UE3 U3 UE4 U2 – Additional BW  Secondary (S)CC-s 1-4 l CC2 Network perspective CC1 – Same single RLC-connection for one UE (independent on the CC-s) UE1 UE2 – Many CC (starting at MAC scheduler) CC2 CC1 UE3 operating the UE l For TDD – Same UL/DL configuration for all CC-s UE4 November 2012 | LTE Introduction | 137
  • Carrier aggregation (CA)General comments, cont’d.l A device capable of carrier aggregation has 1 DL primary component carrier and 1 associated primary UL component carrier. l Basic linkage between DL and UL is signaled in SIB Type 2. l Configuration of primary component carrier (PCC) is UE-specific. – Downlink: cell search / selection, system information, measurement and mobility. – Uplink: access procedure on PCC, control information (PUCCH) on PCC. – Network may decide to switch PCC for a device  handover procedure is used. l Device may have one or several secondary component carriers. Secondary Component Carriers (SCC) added in RRC_CONNECTED mode only. – Symmetric carrier aggregation. – Asymmetric carrier aggregation (= Rel-10). Downlink Uplink SCC SCC SCC PCC SCC PCC SCC SCC SCC SCC 2012 © by Rohde&Schwarz PDSCH and PDCCH PUSCH and PUCCH PDSCH, PDCCH is optional PUSCH only November 2012 | LTE Introduction | 138
  • LTE-AdvancedCarrier Aggregation – Initial Deploymentl Initial LTE-Advanced deployments will likely be limited to the use of two component carrier.l The below are focus scenarios identified by 3GPP RAN4. November 2012 | LTE Introduction | 139
  • Bandwidth  BWChannel(1)  BWChannel( 2)  0.1 BWChannel(1)  BWChannel( 2)  Nominal channel spacing   0.3 MHzl General   0.6   – Up to 5 CC – Up to 100 RB-s pro CC – Up to 500 RB-s aggregatedl Aggregated transmission bandwidth – Sum of aggregated channel bandwidths – Illustration for Intra band contiguous – Channel raster 300 kHzl Bandwidth classes – UE Capability November 2012 | LTE Introduction | 140
  • Bands / Band-Combinations (II)l Under discussion l 25 WI-s in RAN4 with practical interest – Inter band (1 UL CC) – Intra band cont (1 UL CC) – Intra band non cont (1 UL CC) – Inter band (2 UL CC)l Release independency l Band performance is release independent – Band introduced in Rel-11 – Performance tested for Rel- 10 November 2012 | LTE Introduction | 141
  • Carrier aggregation - configurationsl CA Configurations l E-UTRA CA Band + Allowed BW = CA Configuration – Intra band contiguous – Most requirements – Inter band – Some requirements – Main interest of many companies – Intra band non contiguous – No configuration / requirements – Feature of later releases?l CA Requirement applicability – CL_X  Intra band CA – CL_X-Y  Inter band – Non-CA  no CA (explicitely stated for the Test point which are tested differently for CA and not CA) November 2012 | LTE Introduction | 142
  • UE categories for Rel-10 NEW!UE categories 6…8 (DL and UL) Maximum number Maximum number of bits Maximum number of UE of DL-SCH transport Total number of of a DL-SCH transport supported layers for Category block bits received soft channel bits block received within a TTI spatial multiplexing in DL within a TTI … … … … … 149776 (4 layers) Category 6 301504 3654144 2 or 4 75376 (2 layers) 149776 (4 layers) Category 7 301504 3654144 2 or 4 75376 (2 layers) Category 8 2998560 299856 35982720 8 Maximum number ~3 Gbps peak Maximum number Support of UL-SCH Total layer 2 DL data rate of bits of an UL-SCH for UE transport buffer size for 8x8 MIMO transport block 64Q Category block bits [bytes] transmitted within a AM transmitted TTI in UL within a TTI … … … … … 3 300 000 Category 6 51024 51024 No 3 800 000 Category 7 102048 51024 No 42 200 000 Category 8 1497760 149776 Yes ~1.5 Gbps peak November 2012 | LTE Introduction | 143 UL data rate, 4x4 MIMO
  • Deployment scenarios3) Improve coveragel #1: Contiguous frequency aggregation F1 F2 – Co-located & Same coverage – Same fl #2: Discontiguous frequency aggregation – Co-located & Similar coverage – Different fl #3: Discontiguous frequency aggregation – Co-Located & Different coverage – Different f – Antenna direction for CC2 to cover blank spotsl #4: Remote radio heads – Not co-located – Intelligence in central eNB, radio heads = only transmission antennas – Cover spots with more traffic – Is the transmission of each radio head within the cell the same?l #5:Frequency-selective repeaters – Combination #2 & #4 – Different f – Extend the coverage of the 2nd CC with Relays November 2012 | LTE Introduction | 144
  • Physical channel arrangement in downlink Each component carrier transmits P- Each component SCH and S-SCH, carrier transmits Like Rel.8 PBCH, Like Rel.8 November 2012 | LTE Introduction | 145
  • LTE-AdvancedCarrier Aggregation – Scheduling Non-Contiguous spectrum allocation Contiguous RLC transmission buffer Dynamic switching Channel Channel Channel Channel coding coding coding coding Each component HARQ HARQ HARQ HARQ Carrier may use its Data Data Data Data mod. mod. mod. mod. own AMC, Mapping Mapping Mapping Mapping = modulation + coding e.g. 20 MHz scheme [frequency in MHz] November 2012 | LTE Introduction | 146
  • Carrier Aggregation – Architecture downlink 1 UE using carrier aggregation Radio Bearers Radio Bearers ROHC ... ROHC ROHC ... ROHC ROHC ROHCPDCP ... PDCP Security ... Security Security ... Security Security Security Segm. Segm. Segm. Segm. Segm. Segm. Segm. Segm. ... ... ... RLC ... RLC ARQ etc ARQ etc ARQ etc ARQ etc ARQ etc ARQ etc CCCH BCCH PCCH CCCH MCCH MTCH Logical Channels Logical Channels Unicast Scheduling / Priority Handling MBMS Scheduling Scheduling / Priority Handling Multiplexing UE1 ... Multiplexing UEn Multiplexing MultiplexingMAC MAC HARQ ... HARQ HARQ ... HARQ HARQ ... HARQ Transport Channels Transport Channels BCH PCH MCH UL-SCH UL-SCH DL-SCH DL-SCH DL-SCH DL-SCH on CC1 on CCz on CC1 on CCx on CC1 on CCy In case of CA, the multi-carrier nature of the physical layer is only exposed to the MAC layer for which one HARQ entity is required per serving cell November 2012 | LTE Introduction | 147
  • Common or separate PDCCH per Component Carrier?l No cross-carrier scheduling. up to 3 (4) symbols per subframe 1 subframe = 1 ms l PDCCH on a component carrier Time 1 slot = 0.5 ms assigns PDSCH resources on the Frequency same component carrier (and PDCCH PDCCH PUSCH resources on a single PDSCH PDSCH linked UL component carrier). l Reuse of Rel-8 PDCCH structure PDCCH (same coding, same CCE-based PCC PDSCH PDSCH PDCCH resource mapping) and DCI formats.l Cross-carrier scheduling. l PDCCH on a component carrier can assign PDSCH or PUSCH PDSCH PDSCH PDCCH PDCCH resources in one of multiple component carriers using the carrier indicator field. l Rel-8 DCI formats extended with 3 bit carrier indicator field. No cross-carrier Cross-carrier l Reusing Rel-8 PDCCH structure (same scheduling scheduling coding, same CCE-based resource mapping). November 2012 | LTE Introduction | 148
  • Carrier aggregation: control signals + scheduling Each CC has its own control channels, like Rel.8 Femto cells: Risk of interference! -> main component carrier will send all control information. November 2012 | LTE Introduction | 149
  • DCI control elements: CIF field New field: carrier indicator field gives information, which component carrier is valid. => reminder: maximum 5 component carriers!Carrier Indicator Field, CIF, 3bits f f fComponent carrier 1 Component carrier 2 Component carrier N November 2012 | LTE Introduction | 150
  • PDSCH start fieldExample: 1 Resource blockOf a component carrier R R RPCFICH PCFICH PCFICHe.g. PCC e.g. SCC PDCCH Secondary componentPrimary component carriercarrier PDSCH start field indicates positionIn cross-carrier scheduling,the UE does not read the PCFICH andPDCCH on SCC, thus it has to know the start of the PDSCH November 2012 | LTE Introduction | 151
  • Component Carrier – RACH configuration Downlink Asymmetric carrier Aggregation possible, e.g. DL more CC than UL Uplink All CC use same RACH preambleEach CC has its own RACH Network responds on all CCs Only 1 CC contains RACH November 2012 | LTE Introduction | 152
  • Carrier Aggregationl The transmission mode is not constrained to be the same on all CCs scheduled for a UEl A single UE-specific UL CC is configured semi-statically for carrying PUCCH A/N, SR, and periodic CSI from a UEl Frequency hopping is not supported simultaneously with non-contiguous PUSCH resource allocationl UCI cannot be carried on more than one PUSCH in a given subframe. November 2012 | LTE Introduction | 153
  • Carrier Aggregationl Working assumption is confirmed that a single set of PHICH resources is shared by all UEs (Rel-8 to Rel-10)l If simultaneous PUCCH+PUSCH is configured and there is at least one PUSCH transmission l UCI can be transmitted on either PUCCH or PUSCH with a dependency on the situation that needs to be further discussed l All UCI mapped onto PUSCH in a given subframe gets mapped onto a single CC irrespective of the number of PUSCH CCs November 2012 | LTE Introduction | 154
  • UE Architecturesl Possible TX architectures l Same / Different antenna (connectors) for each CC l D1/D2 could be switched to support CA or UL MIMO November 2012 | LTE Introduction | 155
  • LTE–Advanced solutions from R&SR&S® SMU200 Vector Signal Generator November 2012 | LTE Introduction | 156
  • LTE–Advanced solutions from R&SR&S® FSQ Signal Analyzer RBW 2 MHz VBW 5 MHz Ref -20 dBm Att 5 dB SWT 2.5 ms -20 A -30 1 AP CLRWR -40 -10 dB -50 -60 20 MHz 20 MHz E-UTRA carrier 2 -70 E-UTRA carrier 2 EXT fc,E-UTRA carrier 2 = 2135 MHz fc,E-UTRA carrier 2 = 2205 MHz3DB -80 -90 -100 -110 -120 Center 2.17 GHz 10 MHz/ Span 100 MHz LTE-Advanced – An introduction November 2012 | LTE Introduction | 157 Date: 8.OCT.2009 14:13:24 Roessler | October 2009 | 157 A.
  • Enhanced MIMO schemesl Increased number of layers: l Up to 8x8 MIMO in downlink. l Up to 4x4 MIMO in uplink.l In addition the downlink reference signal structure has been enhanced compared with LTE Release 8 by: l Demodulation Reference signals (DM-RS) targeting PDSCH demodulation. – UE specific, i.e. an extension to multiple layers of the concept of Release 8 UE- specific reference signals used for beamforming. l Reference signals targeting channel state information (CSI-RS) estimation for CQI/PMI/RI/etc reporting when needed. – Cell specific, sparse in the frequency and time domain and punctured into the data region of normal subframes. November 2012 | LTE Introduction | 158
  • Cell specific Reference Signals vs. DM-RS LTE Rel.8 LTE-Advanced (Rel.10) CRS0 DM-RS0 CRS0 + CSI-RS0 s1 s1 s2 s2 Pre- Pre- ........ ........ coding coding sN sN Cell specific DM-RSN Cell specific Reference signalsN reference signalsN + Channel status information reference signals 0l Demodulation-Reference signals DM-RS and data are precoded the same way, enabling non-codebook based precoding and enhanced multi-user beamforming. November 2012 | LTE Introduction | 159
  • Ref. signal mapping: Rel.8 vs. LTE-Advanced l Example: LTE (Release 8) LTE-A (Release 10) l 2 antenna ports, antenna port 0,0 1 2 3 4 5 6 0 1 2 3 4 5 6 0 1 2 3 4 5 6 0 1 2 3 4 5 6 CSI-RS configuration 8. l PDCCH (control) allocated in the 1 0x x x x first 2 OFDM symbols. R E L E A S E x x x x l CRS sent on all RBs; DTX sent for the CRS of 2nd antennax x x x port. x x x x l DM-RS sent only for scheduled 8x x x x RBs on all antennas; each set R E L E A S E x x x x coded differently between the two layers.x x x x x x x x l CSI-RS punctures Rel. 8 data; sent periodically over allottedPDSCH PDCCH CRS DM-RS CSI-RS REs (not more than twice per frame) November 2012 | LTE Introduction | 160
  • DL MIMOExtension up to 8x8 Codeword to layer mapping for spatial multiplexingl Max number of transport blocks: 2 Number Number Codeword-to-layer mappingl Number of MCS fields of layers of code words i  0,1, M symb  1 layer l one for each transport block x ( 0) (i)  d ( 0) (2i)l ACK/NACK feedback x (1) (i)  d ( 0) (2i  1) l 1 bit per transport block for evaluation 5 2 M symb  M symb 2  M symb 3 layer ( 0) (1) x (i)  d (3i ) ( 2) (1) as a baseline x (3) (i )  d (1) (3i  1)l Closed-loop precoding supported x ( 4) (i)  d (1) (3i  2) l Rely on precoded dedicated x ( 0) (i )  d ( 0) (3i) x (1) (i )  d ( 0) (3i  1) demodulation RS (decision on DL RS) x ( 2) (i)  d ( 0) (3i  2)l M symb  M symb 3  M symb 3 layer ( 0) (1) 6 2 Conclusion on the codeword-to- x (3) (i)  d (1) (3i) layer mapping: x ( 4) (i)  d (1) (3i  1) x (5) (i )  d (1) (3i  2) l DL spatial multiplexing of up to eight x ( 0) (i )  d ( 0) (3i) layers is considered for LTE-Advanced, x (1) (i )  d ( 0) (3i  1) x ( 2) (i)  d ( 0) (3i  2) l Up to 4 layers, reuse LTE codeword-to- 7 2 M symb  M symb 3  M symb 4 layer ( 0) (1) layer mapping, x (3) (i )  d (1) (4i ) x ( 4) (i )  d (1) (4i  1) l Above 4 layers mapping – see table x (5) (i )  d (1) (4i  2) x ( 6) (i )  d (1) (4i  3)l Discussion on control signaling x ( 0) (i )  d ( 0) (4i ) x (1) (i )  d ( 0) (4i  1) details ongoing x ( 2) (i )  d ( 0) (4i  2) x (3) (i )  d ( 0) (4i  3) 8 2 M symb  M symb 4  M symb 4 layer ( 0) (1) x ( 4) (i)  d (1) (4i) x (5) (i)  d (1) (4i  1) x ( 6) (i )  d (1) (4i  2) x ( 7 ) (i)  d (1) (4i  3) November 2012 | LTE Introduction | 161
  • MIMO – layer and codeword 101Codeword 1: 101111000011101 Codeword 1: 100 111000011101 011 ACK 000Codeword 2: 111 Codeword 2:010101010011 010101010011 001 111 Up to 8 times ACK the data -> Receiver only 8 layers Sends 2 ACK/NACKs November 2012 | LTE Introduction | 162
  • Uplink MIMO Extension up to 4x4l Rel-8 LTE. l UEs must have 2 antennas for reception. l But only 1 amplifier for transmission is available (costs/complexity). l UL MIMO only as antenna switching mode (switched diversity).l 4x4 UL SU-MIMO is needed to fulfill peak data rate requirement of 15 bps/Hz.l Schemes are very similar to DL MIMO modes. l UL spatial multiplexing of up to 4 layers is considered for LTE-Advanced. l SRS enables link and SU-MIMO adaptation.l Number of receive antennas are receiver-implementation specific. l At least two receive antennas is assumed on the terminal side. November 2012 | LTE Introduction | 163
  • UL MIMO – signal generation in uplinkSimilar to Rel.8 Downlink:codewords layers antenna ports Modulation Transform Resource element SC-FDMA Scrambling mapper mapper precoder signal gen. Layer Precoding mapper Modulation Transform Resource element SC-FDMA Scrambling mapper mapper precoder signal gen.Avoidperiodic bit QPSK Up to DFT,sequence 16-QAM 4 layer as in Rel 8, 64-QAM but non- contiguous allocation possible November 2012 | LTE Introduction | 164
  • LTE-AdvancedEnhanced uplink SC-FDMAl The uplink transmission scheme remains SC-FDMA.l The transmission of the physical uplink shared channel (PUSCH) uses DFT precoding.l Two enhancements: l Control-data decoupling l Non-contiguous data transmission November 2012 | LTE Introduction | 165
  • Physical channel arrangement - uplink Simultaneous transmission ofClustered-DFTS-OFDM PUCCH and PUSCH from= Clustered DFT spread the same UE is supportedOFDM.Non-contiguous resource block allocation => will cause higherCrest factor at UE side November 2012 | LTE Introduction | 166
  • LTE-AdvancedEnhanced uplink SC-FDMA Due to distribution we get active subcarriers beside non-active subcarriers: worse peak to average ratio, e.g. Crest factor November 2012 | LTE Introduction | 167
  • What are the effects of “Enhanced SC-FDMA”? Source: http://www.3gpp.org/ftp/tsg_ran/WG4_Radio/TSGR4_54/Documents/R4-101056.zip November 2012 | LTE Introduction | 168
  • Simultaneous PUSCH-PUCCH transmission, multi-cluster transmissionl Remember, only one UL carrier in 3GPP Release 10; scenarios: l Feature support is indicated by PhyLayerParameters-v1020 IE*). PUCCH and PUCCH and fully allocated PUSCH allocated PUSCH f [MHz] f [MHz] PUCCH PUSCH partially PUCCH and partially allocated PUSCH allocated PUSCH f [MHz] f [MHz] *) see 3GPP TS 36.331 RRC Protocol Specification November 2012 | LTE Introduction | 169
  • Benefit of localized or distributed mode „static UE“: frequency selectivity is not time variant -> localized allocation Multipath causes frequency Selective channel, It can be time variant or Non-time variant „high velocity UE“: frequency selectivity is time variant -> distributed allocation November 2012 | LTE Introduction | 170
  • Significant step towards 4G: Relaying ? Source: TTA‘s workshop for the future of IMT-Advanced technologies, June 2008 November 2012 | LTE Introduction | 171
  • Radio Relaying approach No Improvement of SNR resp. CINR Source: TTA‘s workshop for the future of IMT-Advanced technologies, June 2008 November 2012 | LTE Introduction | 172
  • L1/L2 Relaying approach Source: TTA‘s workshop for the future of IMT-Advanced technologies, June 2008 November 2012 | LTE Introduction | 173
  • Present Thrust- Spectrum Efficiency Momentary snapshot of frequency spectrum allocation Why not use this part of the spectrum?l FCC Measurements:- Temporal and geographical variations in the utilization of the assigned spectrum range from 15% to 85%. November 2012 | LTE Introduction | 174
  • ODMA – some ideas… BTSMobile devices behave asrelay station ODMA = opportunity driven multiple access November 2012 | LTE Introduction | 175
  • Cooperative communication How to implement antenna arrays in mobile handsets? Multi-access Independent fading paths Each mobile is user and relay 3 principles of aid: •Amplify and forward •Decode and forward •Coded cooperation November 2012 | LTE Introduction | 176
  • Cooperative communication Multi-access Independent fading pathsVirtual Higher signalingAntenna System complexityArray Cell edge coverage Group mobility November 2012 | LTE Introduction | 177
  • LTE, UMTS Long Term EvolutionLTE measurements – from RF toapplication testing Reiner Stuhlfauth Reiner.Stuhlfauth@rohde-schwarz.com Training Centre Rohde & Schwarz, GermanySubject to change – Data without tolerance limits is not binding.R&S® is a registered trademark of Rohde & Schwarz GmbH & Co. KG. Trade names are trademarksof the owners. 2011 ROHDE & SCHWARZ GmbH & Co. KG Test & Measurement Division - Training Center -This folder may be taken outside ROHDE & SCHWARZ facilities.ROHDE & SCHWARZ GmbH reserves the copy right to all of any part of these course notes.Permission to produce, publish or copy sections or pages of these notes or to translate them must firstbe obtained in writing fromROHDE & SCHWARZ GmbH & Co. KG, Training Center, Mühldorfstr. 15, 81671 Munich, Germany
  • Mobile Communications: Fields for testingl RF testing for mobile stations and user equipmentl RF testing for base stationsl Drive test solutions and verification of network planningl Protocol testing, signaling behaviourl Testing of data end to end applicationsl Audio and video quality testingl Spectrum and EMC testing November 2012 | LTE Introduction | 179
  • Test Architecture RF-/L3-/IP Application-Test November 2012 | LTE Introduction | 180
  • LTE measurements general aspectsNovember 2012 | LTE Introduction | 181
  • LTE RF Testing AspectsUE requirements according to 3GPP TS 36.521Power Transmit signal quality  Maximum output power Frequency error  Maximum power reduction Modulation quality, EVM  Additional Maximum Power Carrier Leakage Reduction In-Band Emission for non allocated RB  Minimum output power EVM equalizer spectrum flatness  Configured Output Power Output RF spectrum emissions  Power Control  Occupied bandwidth  Absolution Power Control  Out of band emissions  Relative Power Control  Aggregate Power Control  Spectrum emisssion mask  ON/OFF Power time mask  Additional Spectrum emission mask  Adjacent Channel Leakage Ratio36.521: User Equipment (UE) radiotransmission and reception Transmit Intermodulation November 2012 | LTE Introduction | 182
  • LTE RF Testing AspectsUE requirements according to 3GPP, cont. Receiver characteristics:  Reference sensitivity level  Maximum input level  Adjacent channel selectivity  Blocking characteristics  In-band Blocking  Out of band Blocking  Narrow Band Blocking  Spurious response  Intermodulation characteristics  Spurious emissions Performance November 2012 | LTE Introduction | 183
  • LTE bands and channel bandwidth E-UTRA band / channel bandwidth E-UTRA Band 1.4 MHz 3 MHz 5 MHz 10 MHz 15 MHz 20 MHz 1 Yes Yes Yes Yes 2 Yes Yes Yes Yes Yes[1] Yes[1] 3 Yes Yes Yes Yes Yes[1] Yes[1] 4 Yes Yes Yes Yes Yes Yes 5 Yes Yes Yes Yes[1] 6 Yes Yes[1] 7 Yes Yes Yes Yes[1] 8 Yes Yes Yes Yes[1] 9 Yes Yes Yes[1] Yes[1] 10 Yes Yes Yes Yes 11 Yes Yes[1] 12 Yes Yes Yes[1] Yes[1] 13 14 Yes[1] Yes[1] Yes[1] Yes[1] Not every channel ... 17 Yes[1] Yes[1] bandwidth for ... every band! 33 Yes Yes Yes Yes 34 Yes Yes Yes 35 Yes Yes Yes Yes Yes Yes 36 Yes Yes Yes Yes Yes Yes 37 Yes Yes Yes Yes 38 Yes Yes Yes Yes 39 Yes Yes Yes Yes 40 Yes Yes Yes Yes NOTE 1: bandwidth for which a relaxation of the specified UE receiver sensitivity requirement (Clause 7.3) is allowed. November 2012 | LTE Introduction | 184
  • Tests performed at “low, mid and highest frequency” Nominal frequency RF power described by EARFCN (E-UTRA Absolute lowest EARFCN possible Radio Frequency Channel Number) and 1 RB at position 0 Frequency = whole LTE band RF power mid EARFCN and 1 RB at position 0 Frequency RF power Highest EARFCN and 1 RB at max position Frequency November 2012 | LTE Introduction | 185
  • LTE RF measurementson user equipment UEs November 2012 | LTE Introduction | 186
  • LTE Transmitter Measurements 1 Transmit power 1.1 UE Maximum Output Power 1.2 Maximum Power Reduction (MPR) 1.3 Additional Maximum Power Reduction (A-MPR) 1.4 Configured UE transmitted Output Power 2 Output Power Dynamics 2.1 Minimum Output Power 2.2 Transmit OFF power 2.3 ON/OFF time mask 2.3.1 General ON/OFF time mask 2.3.2 PRACH time mask 2.3.3 SRS time mask 2.4 Power Control 2.4.1 Power Control Absolute power tolerance 2.4.2 Power Control Relative power tolerance 2.4.3 Aggregate power control tolerance 3 Transmit signal quality 3.1 Frequency Error 3.2 Transmit modulation 3.2.1 Error Vector Magnitude (EVM) 3.2.2 Carrier leakage 3.2.3 In-band emissions for non allocated RB 3.2.4 EVM equalizer spectrum flatness 4 Output RF spectrum emissions 4.1 Occupied bandwidth 4.2 Out of band emission 4.2.1 Spectrum Emission Mask 4.2.2 Additional Spectrum Emission Mask 4.2.3 Adjacent Channel Leakage power Ratio 4.3 Spurious emissions 4.3.1 Transmitter Spurious emissions 4.3.2 Spurious emission band UE co-existence 4.3.3 Additional spurious emissions 5 Transmit intermodulation November 2012 | LTE Introduction | 187
  • UE Signal quality – symbolic structure ofmobile radio tester MRT Test equipment Rx TxRx EVM … … … equalizer IDFT meas. DUT RF correction FFT Inband- … … … emmissionsl Carrier Frequency errorl EVM (Error Vector Magnitude)l Origin offset + IQ offsetl Unwanted emissions, falling into non allocated resource blocks.l Inband transmissionl Spectrum flatness November 2012 | LTE Introduction | 188
  • UL Power Control: Overview UL-Power Control is a combination of: l Open-loop: UE estimates the DL-Path- loss and compensates it for the UL l Closed-loop: in addition, the eNB controls directly the UL- Power through power- control commands transmitted on the DL November 2012 | LTE Introduction | 189
  • PUSCH power control l Power level [dBm] of PUSCH is calculated every subframe i based on the following formula out of TS 36.213 MPR Maximum allowed UE power in this particular cell, Combination of cell- and UE-specific PUSCH transport but at maximum +23 dBm1) components configured by L3 format Number of allocated Cell-specific Downlink Power control resource blocks (RB) parameter path loss adjustment derivedTransmit power for PUSCH configured by L3 estimate from TPC commandin subframe i in dBm received in subframe (i-4) Bandwidth factor Basic open-loop starting point Dynamic offset (closed loop) 1) +23 dBm is maximum allowed power in LTE according to TS 36.101, corresponding to power class 3bis in WCDMA November 2012 | LTE Introduction | 190
  • LTE RF Testing: UE Maximum PowerUE transmitswith 23dBm ±2 dBQPSK modulation is used. All channel bandwidths aretested separately. Max power is for all band classesTest is performed for varios uplink allocations November 2012 | LTE Introduction | 191
  • Resource Blocks number and maximum RF power 1 active resource block (RB), NominalRF power band width One active resource block 10 MHz = 50 RB’s (RB) provides maximum absolute RF power Frequency More RB’s in use will be atRF power lower RF power in order to create same integrated power FrequencyRF power Additionally, MPR (Max. Power Reduction) and A- MPR MPR are defined Frequency November 2012 | LTE Introduction | 192
  • UE maximum power PPowerClass + 2dB 23dBm PPowerClass - 2dB maximum output FUL_highFUL_low power for any transmission bandwidth within the channel bandwidth November 2012 | LTE Introduction | 193
  • UE maximum power – careful at band edge! PPowerClass + 2dB 23dBm PPowerClass - 2dB-1.5dB -1.5dB FUL_low FUL_high- 4MHz FUL_high FUL_low+4MHz For transmission bandwidths confined within FUL_low and FUL_low + 4 MHz or FUL_high – 4 MHz and FUL_high, the maximum output power requirement is relaxed by reducing the lower tolerance limit by 1.5 dB November 2012 | LTE Introduction | 194
  • LTE RF Testing: UE Minimum PowerUE transmitswith -40dBmAll channel bandwidths are tested separately.Minimum power is for all band classes < -39 dBm November 2012 | LTE Introduction | 195
  • LTE RF Testing: UE Off PowerThe transmit OFF power is defined as the mean power in a duration of at least onesub-frame (1ms) excluding any transient periods. The transmit OFF power shall notexceed the values specified in table below Channel bandwidth / Minimum output power / measurement bandwidth 1.4 3.0 5 10 15 20 MHz MHz MHz MHz MHz MHz Transmit OFF power -50 dBm Measurement 1.08 MHz 2.7 MHz 4.5 MHz 9.0 MHz 13.5 MHz 18 MHz bandwidth November 2012 | LTE Introduction | 196
  • Configured UE transmitted Output Power IE P-Max (SIB1) = PEMAX To verify that UE follows rules sent via system information, SIB Test: set P-Max to -10, 10 and 15 dBm, measure PCMAX Channel bandwidth / maximum output power 1.4 3.0 5 10 15 20 MHz MHz MHz MHz MHz MHz PCMAX test point 1 -10 dBm ± 7.7 PCMAX test point 2 10 dBm ± 6.7 PCMAX test point 3 15 dBm ± 5.7 November 2012 | LTE Introduction | 197
  • LTE Power versus time RB allocation is main source for power change Not scheduled Resource blockPPUSCH (i)  min{PMAX ,10 log10 (M PUSCH (i))  PO_PUSCH ( j )    PL   TF (TF (i))  f (i)} Bandwidth allocation Given by higher layers TPC commands or not used November 2012 | LTE Introduction | 198
  • Accumulative TPC commands TPC Command Field Accumulated In DCI format 0/3  PUSCH [dB] 0 -1 1 0 2 1 3 3 2 minimum power in LTE November 2012 | LTE Introduction | 199
  • Absolute TPC commandsPPUSCH (i)  min{ PMAX ,10 log 10 ( M PUSCH (i))  PO_PUSCH ( j )    PL   TF (TF (i))  f (i)} TPC Command Field Absolute  PUSCH [dB] In DCI format 0/3 only DCI format 0 0 -4 1 -1 2 1 3 4Pm -1 -4 November 2012 | LTE Introduction | 200
  • Relative Power Control Power pattern B Power pattern A RB change RB change 0 .. 9 sub-frame# 0 .. 9 sub-frame# 1 2 3 4 radio frame 1 2 3 4 radio frame Power pattern C l The purpose of this test is to verify RB change the ability of the UE transmitter to set its output power relatively to the power in a target sub-frame, relatively to the power of the most recently transmitted reference sub-frame, if the 0 .. 1 9 sub-frame# 2 3 4 radio frame transmission gap between these sub- frames is ≤ 20 ms. November 2012 | LTE Introduction | 201
  • Power Control – Relative Power Tolerancel Various power ramping patterns are defined ramping down alternating ramping up November 2012 | LTE Introduction | 202
  • UE power measurements – relative power change Power Power FDD test patterns TDD test patterns test for each bandwidth, here 10MHz 0 1 9 sub-frame# 0 2 3 7 8 9 sub-frame#Sub-test Uplink RB allocation TPC command Expected power Power step size step size range (Up or PUSCH/ (Up or down) down) ΔP [dB] ΔP [dB] [dB] A Fixed = 25 Alternating TPC = 1 ΔP < 2 1 ± (1.7) +/-1dB B Alternating 10 and 18 TPC=0dB 2.55 2 ≤ ΔP < 3 2.55 ± (3.7) C Alternating 10 and 24 TPC=0dB 3.80 3 ≤ ΔP < 4 3.80 ± (42.) D Alternating 2 and 8 TPC=0dB 6.02 4 ≤ ΔP < 10 6.02 ± (4.7) E Alternating 1 and 25 TPC=0dB 13.98 10 ≤ ΔP < 15 13.98 ± (5.7) F Alternating 1 and 50 TPC=0dB 16.99 15 ≤ ΔP 16.99 ± (6.7) November 2012 | LTE Introduction | 203
  • UE aggregate power toleranceAggregate power control tolerance is the ability of a UE to maintain its power innon-contiguous transmission within 21 ms in response to 0 dB TPC commands TPC command UL channel Aggregate power tolerance within 21 ms 0 dB PUCCH ±2.5 dB 0 dB PUSCH ±3.5 dB Note: 1. The UE transmission gap is 4 ms. TPC command is transmitted via PDCCH 4 subframes preceding each PUCCH/PUSCH transmission. Tolerated UE power P deviation UE power with TPC = 0 Time = 21 milliseconds November 2012 | LTE Introduction | 204
  • UE aggregate power tolerance Power Power FDD test patterns TDD test patterns 0 5 0 5 0 3 8 3 8 3 sub-frame# sub-frame# Test performed with scheduling gap of 4 subframes November 2012 | LTE Introduction | 205
  • UE power measurement – timing masks Start Sub-frame End sub-frame Start of ON power End of ON power End of OFF power Start of OFF power requirement requirement * The OFF power requirements does not apply for DTX and measurement gaps 20µs 20µs Transient period Transient period Timing definition OFF – ON commands Timing definition ON – OFF commands November 2012 | LTE Introduction | 206
  • Power dynamics PUSCH = OFF PUSCH = ON PUSCH = OFF timePlease note: scheduling cadence for power dynamics November 2012 | LTE Introduction | 207
  • Tx power aspectsRB power = Ressource Block Power, power of 1 RBTX power = integrated power of all assigned RBs November 2012 | LTE Introduction | 208
  • Resource allocation versus time PUCCH allocation No resource scheduledPUSCH allocation, different #RB and RB offset November 2012 | LTE Introduction | 209
  • LTE scheduling impact on power versus timeTTI based scheduling.Different RB allocation Impact on UE power November 2012 | LTE Introduction | 210
  • Transmit signal quality – carrier leakage Frequency error fc Fc+ε f Carrier leakage (The IQ origin offset) is an additive sinusoid waveform that has the same frequency as the modulated waveform carrier frequency. Parameters Relative Limit (dBc) Output power >0 dBm -25 -30 dBm ≤ Output power ≤0 dBm -20 -40 dBm  Output power < -30 dBm -10 November 2012 | LTE Introduction | 211
  • Impact on Tx modulation accuracy evaluationl 3 modulation accuracy requirements l EVM for the allocated RBs l LO leakage for the centred RBs ! LO spread on all RBs l I/Q imbalance in the image RBs LO leakage level RF carrier signal I/Q imbalance noise RB0 RB1 RB2 RB3 RB4 RB5 frequency EVM November 2012 | LTE Introduction | 212
  • Inband emissions3 types of inband emissions: general, DC and IQ image Usedallocation <½ channel bandwidth channel bandwidth November 2012 | LTE Introduction | 213
  • Carrier LeakageCarrier leakage (the I/Q origin offset) is a form of interference caused by crosstalk or DC offset.It expresses itself as an un-modulated sine wave with the carrier frequency.I/Q origin offset interferes with the center sub carriers of the UE under test.The purpose of this test is to evaluate the UE transmitter to verify its modulation quality interms of carrier leakage. DC carrier leakage due to IQ offset LO Parameters Relative Leakage Limit (dBc) Output power >0 dBm -25 -30 dBm ≤ Output power ≤0 dBm -20 -40 dBm  Output power < -30 dBm -10 November 2012 | LTE Introduction | 214
  • Inband emmission – error cases DC carrier leakage due to IQ offset November 2012 | LTE Introduction | 215
  • Inband emmission – error cases Inband image due to IQ inbalance November 2012 | LTE Introduction | 216
  • DC leakage and IQ imbalance in real world … November 2012 | LTE Introduction | 217
  • UL Modulation quality: Constellation diagramLTE PUSCH usesQPSK, 16QAMand 64 QAM (optional)modulation schemes.In UL there is only 1 schemeallowed per subframe November 2012 | LTE Introduction | 218
  • Error Vector Magnitude, EVM Q Magnitude Error (IQ error magnitude) Error Vector Measured Signal Ideal (Reference) Signal Φ Phase Error (IQ error phase) I Reference Waveform 011001… Ideal Demodulator Modulator - Input Signal Σ Difference Signal + Measured Waveform November 2012 | LTE Introduction | 219
  • Error Vector Magnitude, EVM 7 symbols / slot 0123456 0123456 0123456 0123456 time PUSCH symbolfrequency Demodulation Reference symbol, DMRS Limit values Unit Level Parameter QPSK % 17.5 16QAM % 12.5 64QAM % [tbd] November 2012 | LTE Introduction | 220
  • Error Vector Magnitude, EVM CP center 1 SC-FDMA symbol, including Cyclic Prefix, CP OFDM Cyclic Symbol prefix Part equal to CP FFT Window size FFT window size depends on channel bandwidth and extended/normal CP length November 2012 | LTE Introduction | 221
  • Cyclic prefix aspects We can observe a phase shift CP CPCP part CP partOFDM symbol n-1 OFDM symbol n Content is OFDM symbol is periodic! different in each OFDM symbol Cyclic prefix does not provoque phase shift November 2012 | LTE Introduction | 222
  • Time windowing 1 SC-FDMA symbol, including Cyclic Prefix, CP 1 SC-FDMA symbol, including Cyclic Prefix, CP OFDM OFDMCyclic Symbol Cyclic Symbolprefix Part equal prefix Part equal to CP to CP Continuous phase shift Difference in phase shift Phase shift between SC-FDMA symbols will cause side lobes in spectrum display! November 2012 | LTE Introduction | 223
  • Time windowing Tx time window creates some kind of clipping in symbol transitions Tx Time window Tx Time window OFDM OFDMCyclic Symbol Cyclic Symbolprefix Part equal prefix Part equal to CP to CP Continuous phase shift Difference in phase shift Tx time window can be used to shape the Tx spectrum in a more steep way, but …. November 2012 | LTE Introduction | 224
  • Time windowing Tx time window creates some kind of clipping in symbol transitions Tx Time window Tx Time window OFDM OFDMCyclic Symbol Cyclic Symbolprefix Part equal prefix Part equal to CP to CP Continuous phase shift Difference in phase shift Tx time window will create a higher Error Vector Magnitude! Here the Tx time window of 5µsec causes Some mismatch between the 2 EVM Measurements of the first SC-FDMA symbol November 2012 | LTE Introduction | 225
  • EVM vs. subcarrier Nominal subcarriers Each subcarrier Modulated with e.g. QPSK Integration of all f Error Vectors to Display EVM curve f0 f1 f2 f3 Error vector .... Error vectorNote: simplified figure: in reality youcompare the waveforms due to SC-FDMA November 2012 | LTE Introduction | 226
  • EVM vs. subcarrier November 2012 | LTE Introduction | 227
  • EVM Equalizer Spectrum FlatnessThe EVM equalizer spectrum flatness is defined as the variation in dB of the equalizer coefficientsgenerated by the EVM measurement process.The EVM equalizer spectrum flatness requirement does not limit the correction applied to the signalin the EVM measurement process but for the EVM result to be valid,the equalizer correction that was applied must meet theEVM equalizer spectral flatness minimum requirements. Nominal subcarriers Amplitude Equalizer coefficients f f0 f1 f2 f3 Subcarriers before equalizationIntegration of all 1amplitude equalizercoefficients to display | A( EC ( f )) |2 12 * N RB 12* N RB P( f )  10 * logspectral flatness curve | A( EC ( f ) |2 November 2012 | LTE Introduction | 228
  • Spectrum flatness calculation1-tap equalization =Interpreting the frequency Equalizer tries toSelectivity as scalar factor set same power level for all subcarriers A(f) 1 1-tap equalization = | A( EC ( f )) |2 12 * N RB 12* N RB Calculating scalar to P( f )  10 * log amplify or attenuate | A( EC ( f ) |2 f November 2012 | LTE Introduction | 229
  • Spectral flatness November 2012 | LTE Introduction | 230
  • Output RF Spectrum Emissions Out-of-band emissions occupied Spurious Emissions bandwidth Spectrum Emission Mask – SEM -> measurement point by point (RBW)Adjacent Channel Leakage Ratio – ACLR -> integration (channel bandwidth) Channel Spurious domain ΔfOOB bandwidth ΔfOOB Spurious domain RB E-UTRA Band Worst case: from Harmonics, parasitic Resource Blocks allocated at modulation emissions, intermodulation channel edge process and frequency conversion November 2012 | LTE Introduction | 231
  • Adjacent Channel Leakage Ratio, ACLR Active LTE carrier, 20MHz BW 1 adjacent LTE carrier, 20MHz BW 2 adjacent WCDMA carriers, 5MHz BW November 2012 | LTE Introduction | 232
  • Occupied Bandwidth - OBW Occupied bandwidth is defined as the bandwidth containing 99 % of the total integrated mean power of the transmitted spectrum 99% of mean power Channel Bandwidth [MHz] Transmission Bandwidth Configuration [RB] Transmission Bandwidth [RB] Channel edgeChannel edge Resource block Active Resource Blocks DC carrier (downlink only) November 2012 | LTE Introduction | 233
  • Impact on SEM limit definition Limits depend on channel bandwidth Spectrum emission limit (dBm)/ Channel bandwidth ΔfOOB 1.4 3.0 5 10 15 20 Measurement (MHz) MH M M M M M bandwidth z Hz Hz Hz Hz Hz  0-1 -10 -13 -15 -18 -20 -21 30 kHz  1-2.5 -10 -10 -10 -10 -10 -10 1 MHz  2.5-5 -25 -10 -10 -10 -10 -10 1 MHz  5-6 -25 -13 -13 -13 -13 1 MHz Limits vary  6-10 -25 -13 -13 -13 1 MHz dependent on offset  10-15 -25 -13 -13 1 MHz from assigned BW  15-20 -25 -13 1 MHz  20-25 -25 1 MHz November 2012 | LTE Introduction | 234
  • LTE Uplink: PUCCH Allocation of PUCCH only. frequency November 2012 | LTE Introduction | 235
  • PUCCH measurements PUCCH is transmitted on the 2 side parts of the channel bandwidth November 2012 | LTE Introduction | 236
  • LTE Receiver Measurements 1 Reference sensitivity level 2 Maximum input level 3 Adjacent Channel Selectivity (ACS) 4 Blocking characteristics 4.1 In-band blocking 4.2 Out-of-band blocking 4.3 Narrow band blocking 5 Spurious response 6 Intermodulation characteristics 6.1 Wide band Intermodulation 7 Spurious emissions November 2012 | LTE Introduction | 237
  • RX Measurements – general setup AWGN Receive Sensitivity Tests Blockers Adjacent channels Transmit data User according to definable table on PDSCH DL Use both assignment Rx Antennas Table (TTI based) + Receive feedbackSpecifies DL scheduling on PUSCHparameters like or PUCCHRB allocationModulation, etc.for every TTI (1ms) ACK/NACK/DTX Counting requirements in terms of throughput (BLER) instead of BER November 2012 | LTE Introduction | 238
  • RX sensitivity levelCriterion: throughput shall be > 95% of possible maximum(depend on RMC) Channel bandwidth E-UTRA 1.4 MHz 3 MHz 5 MHz 10 MHz 15 MHz 20 MHz Duplex Ban (dBm) (dBm) (dBm) (dBm) (dBm) (dBm) Mode d 1 - - -100 -97 -95.2 -94 FDD 2 -104.2 -100.2 -98 -95 -93.2 -92 FDD 3 -103.2 -99.2 -97 -94 -92.2 -91 FDD 4 -106.2 -102.2 -100 -97 -95.2 -94 FDD 5 -104.2 -100.2 -98 -95 FDD 6 - - -100 -97 FDD Extract from TS 36.521 Sensitivity depends on band, channel bandwidth and RMC under test November 2012 | LTE Introduction | 239
  • Block Error Ratio and ThroughputRxquality DL signal Criterion: throughput shall be Channel > 95% of possible maximum setup (depending on RMC) November 2012 | LTE Introduction | 240
  • Rx measurements: BLER definition PDCCH, scheduling info PDSCH, as PRBS Count #NACKs and ACK/NACK feedback calculate BLER Assumption is that eNB Power = UE Rx power November 2012 | LTE Introduction | 241
  • Details LTE FDD signalingRx Measurements l Rx Measurements l Counting – ACKnowledgement (ACK) – NonACKnowledgement (NACK) – DTX (no answer from UE) l Calculating l BLER (NACK/ALL) l Throughput [kbps] November 2012 | LTE Introduction | 242
  • Rx measurements: BLER definition PDCCH, scheduling info •ACK = UE properly Receives PDCCH + PDSCH •NACK = UE properly receives PDCCH but does not understand PDSCH •DTX = UE does not understand PDSCH, user data PDCCH ACK/NACK feedback # NACK  # DTX # ACK BLER = ACK relative = # ACK  # NACK  # DTX # ACK  # NACK  # DTX # NACK NACK relative = # ACK  # NACK  # DTX # DTX DTX relativ = # ACK  # NACK  # DTX November 2012 | LTE Introduction | 243
  • Throughput versus SNR November 2012 | LTE Introduction | 244
  • Throughput measurements Max throughput possible in SISO November 2012 | LTE Introduction | 245
  • Rx measurements - throughputThroughputMeasurement,Settings for maxthroughputfor SISO:Number ofResource blocksModulation schemeTransport block size November 2012 | LTE Introduction | 246
  • Throughput + CQI in LTEChange of RFcondition- > lowerdata rateUE sends different CQI values November 2012 | LTE Introduction | 247
  • MIMO in LTE: BLER and throughput November 2012 | LTE Introduction | 248
  • Throughput measurements MIMO active, 2 streams with different data rate November 2012 | LTE Introduction | 249
  • Why do we need fading?l 3GPP specifies various tests under conditions of fading l WCDMA performance tests l HSDPA performance tests l LTE performance tests l LTE reporting of channel state information testsSee CMW capability lists for detailsl Evaluation of MIMO performance gain requires fading l Correlated transmission paths in MIMO connection l Simulation of “real life conditions” in the lab l Comparison of processing gain for different transmission modes November 2012 | LTE Introduction | 250
  • Most popular MIMO scheme to increase data rates: Spatial Multiplexing h 11 h 12 TX Ant 1 h 21 Space h22 RX Matix B Ant 1 n1 TX d1 Ant 2 RX r1 de1 Ant 2 MIMO LO 2X2 RX d2 (e.g. ZF, MIMO r2 MMSE,MLD) de2 Time n2No increase of total transmit power, i.e. distribution of transmit power across multiple transmit antennas! Doubles max. data rates, however, at the expense of SNR @ receiver. Thus, according to Shannon‘s law, decrease of performance. Makes sense for low order modulation schemes only (QPSK, 16QAM), or in case of very good SNR conditions, e.g. for receivers close to base stations. November 2012 | LTE Introduction | 251
  • Internal fading in LTE November 2012 | LTE Introduction | 252
  • BLER results with and without fading November 2012 | LTE Introduction | 253
  • The mobile device evolution Voice Call SMS MMS WAP E-Mail Voice Call Internet Access SMS IPv4 MMS IPv6 WAP VoIP (Skype) Voice Call E-Mail Games SMS Internet Access Video Call MMS IPv4 A-GPS/SUPL2.0 WAP IPv6 IMS support E-Mail VoIP (Skype) SMS over IMSVoice Call Internet Access Games Voice/Video over IMSSMS IPv4 A-GPS CSFB… ... ... ...2G 2.5G/2.75G 3G/3.5G 3.9G/4GGSM GPRS/EDGE UMTS/HSPA LTE/LTE-A/HSPA-DC November 2012 | LTE Introduction | 254
  • Why End-to-End testing?Voice Call All features on a phone have an direct impact on the battery life of the phone and it’sSMS power consumption, but also on the generated traffic by the phone.MMSWAPE-Mail Keywords:Internet Access lHW and SW of a phone need to be designed in an efficient way for a long battery lifeIPv4IPv6 lHW and SW need to be designed in a way, that they provide the service reliableVoIP (Skype) lEfficient application desig for low IP trafficGames ...Video CallA-GPS/SUPL2.0IMS support Focus:SMS over IMSVoice/Video over IMS lValidation of HW and SW in combinationCSFB l Simulation of end-user scenarios in an isolated and controlled environment... l Validation of applications with repeatable and comparable results …Smartphone That‘s why End-to-End test! November 2012 | LTE Introduction | 255
  • Here it is! The „Data Application Unit“! Embedded PC based on Linux! November 2012 | LTE Introduction | 256
  • CMW DAU - Main Features1. Easy Data Testing IP configuration l Ready to use Standalone IP configuration for the CMW l Easy Company LAN integration (DHCPv4, static IP addresses) l Data continuity during Handover between RATs l Remote control by MLAPI & SCPI2. DAU IP services (Applications) l Provides R&S throughput optimized data applications (ftp, http, …) l New features like IMS (for VoLTE or SMS over IMS) l Provides storage for media files (own Hard Disk)3. Closed environment l guaranties repeatable and comparable test results November 2012 | LTE Introduction | 257
  • DAU User Interface on the CMWl Data Application Control (DAC) l Accessible via Setup-> System -> DAU -> Go to Config l Data Testing IP configuration l Start/Stop, Configure global servers like FTP, HTTP November 2012 | LTE Introduction | 258
  • DAU User Interface on the CMWl Data Application Measurements (DAM) l Accessible over the CMW Measurements l Provides User Interface for – Applications: start Iperf, trigger Ping, send/receive eMails … – Measurements: Throughput, Traffic statistics Go to DAC November 2012 | LTE Introduction | 259
  • Feature SetFW2.1.26 Latency Throughput Overall measurements Indication IPERF Throughput Measurement November 2012 | LTE Introduction | 260
  • Throughput end to end November 2012 | LTE Introduction | 261
  • End to end testing – ping response, RTT November 2012 | LTE Introduction | 262
  • Integrated ServersFW2.1.26 November 2012 | LTE Introduction | 263
  • Introduction IMS – IP Multimedia SubsystemDefinitionl IMS (IP multimedia subsystem) itself is not a technology, it is an architecturel IMS is an all-IP service layer between transport and application layer based on common Internet protocolsl IMS architecture enables the connection to networks using multiple mobile and fixed devices and technologiesl IMS defines an architecture for the convergence of audio, video and data to enable integrated Multimedia Sessions over fixed and wireless networksl The long-term solution for supporting voice services in LTE will be based on the IMS (IP Multimedia Subsystem) framework. November 2012 | LTE Introduction | 264
  • Introduction IMS – IP Multimedia SubsystemDefinition Services: l TBD SMS over IMS Voice over IMS Video over IMS IMS is a global access-independent and standard-based IP connectivity and service control architecture that enables various types of multimedia services to end-users using common Internet-based protocols. November 2012 | LTE Introduction | 265
  • 3 GPP System Architecture Evolution Signaling interfaces Data transport interfaces RAN Access PDN directly or via IMS MME PDNUE Evolved nodeB S-GW P-GW IMS Evolved Packet Core PSTN external IMS to control All interfaces are packet switched access + data transfer November 2012 | LTE Introduction | 266
  • IMS Architecture November 2012 | LTE Introduction | 267
  • IMS protocol structure user plane Control plane Voice messaging video SIP/SDP IKE RTP MSRP UDP / TCP / SCTPLayer 3 control IP / IP sec Layer 1/2 Layer 1/2 (other IP CAN)Mobile com specific protocols IMS specific protocols November 2012 | LTE Introduction | 269
  • IMS Registration and AuthenticationComparison with LTE LTE IMS ATTACH REQUEST REGISTER AUTHENTICATION REQ 401 UNAUTHORIZED AUTHENTICATION RSP REGISTER ATTACH ACCEPT 200 OK November 2012 | LTE Introduction | 270
  • How to connect E-UTRAN to CS services?l Connection via IMS: 3GPP and OneVoice initiative First a big mess, Now it seems to be OneVoicel Voice over LTE Generic Access – VoLGA Forum – interim solutionl CS Fallback CSFB for voice calls to 2G or 3G services – preferred interim solutionl Evolved MSC, eMSC – CS Services via EPS – network operator proposal, interim solutionl SRVCC – Single Radio Voice Call Continuityl SV-LTE – simultaneous voice and LTEl OTT, Over the top – propietary solution, application based November 2012 | LTE Introduction | 271
  • Voice over IMS: IMS protocol profileAdaptive Multirate Codec mode AMR_12.20 Source codec bit-rate 12,20 kbit/s (GSM EFR)Codecs are used AMR_10.20 AMR_7.95 10,20 kbit/s 7,95 kbit/sIn VoIP over IMS AMR_7.40 7,40 kbit/s (IS-641) AMR_6.70 6,70 kbit/s (PDC-EFR) AMR_5.90 5,90 kbit/s AMR_5.15 5,15 kbit/s AMR_4.75 4,75 kbit/s AMR_SID 1,80 kbit/s (see note 1) November 2012 | LTE Introduction | 272
  • QoS class identifiers QCI QCI Resource Priority Packet Delay Packet Error Example Services Type Budget Loss Rate 1 2 100 ms 10-2 Conversational Voice 2 4 150 ms 10-3 Conversational Video (Live Streaming) GBR 3 3 50 ms 10-3 Real Time Gaming 4 5 300 ms 10-6 Non-Conversational Video (Buffered Streaming) 5 1 100 ms 10-6 IMS Signalling Video (Buffered Streaming) 6 6 300 ms TCP-based (e.g. www, e-mail, chat, ftp, p2p 10-6 file sharing, progressive video, etc.) Non-GBR Voice, Video (Live Streaming), 7 7 100 ms 10-3 Interactive Gaming 8 8 Video (Buffered Streaming) 300 ms TCP-based (e.g. www, e-mail, chat, ftp, p2p 9 9 10-6 file sharing, progressive video, etc.) November 2012 | LTE Introduction | 273
  • Voice over LTE – protocol profiles AMR codec Optimize transmission of Voice by configuring UDP/ TCP Lower layers IPUse robust header compression or IP Packet Data ConvergenceShort PDCP header is used PDCP Use RLC in UM mode Small sequence number is used Radio Link Control RLCSRB1 and 2 are supported forDCCH + one UM DRB with QCI 1 for voicefor SIP signaling + one AM DRB QCI 5 for Medium Access ControlSIP signaling + one AM DRB QCI 8 for MACIMS trafficTTI bundling + DRX to reduce PDCCHSignaling + Semi-persistend scheduling PHYSICAL LAYER November 2012 | LTE Introduction | 274
  • CMW500 Data Application UnitIntegrated IMS Server IMS Configuration IMS infoscreen Mobile infoscreen November 2012 | LTE Introduction | 275
  • IP Based communication client- Source- Destination Routing decision based on: - load - cost of routing - broken links Cause in: - packet delay server - jitter - losses November 2012 | LTE Introduction | 276
  • CMW500 Data Application UnitNetwork ImpairmentEmulate characteristics of a real network l Impairments: l Delay l Jitter DAU l Packet Loss Application LANDAU l Packet Corruption FTP TUN Delay PING Loss l Packet Duplication HTTP l Packet Re-ordering IPERF NOTE: Network Impairment are available for DL traffic November 2012 | LTE Introduction | 277
  • CMW500 Data Application UnitNetwork Impairmentl UP to 7 different Impairment per DAM possiblel Impairments are identified by a filter rule l IPv4 address filter l IPv6 address/prefix filter l Additionally a optional TCP/UDP Port filterl Feedback provided when error occur November 2012 | LTE Introduction | 278
  • Voice over LTE (VoLTE) testingR&S solutions - Overview  LTE attach procedure  IMS registration Audio: echo verification in  LTE attach procedure loopback mode  IMS Terminal Testing IP Traffic Logging  Session Initiation Protocol (SIP) Impact of noise, IP traffic impairment  Conformance Testing R&S®CMW500  Audio: echo verification in LTE Call-box loopback mode Audio Functional Quality testingR&S®CMW500 LTE Protocol Tester testingR&S®CMW-PQA R&S®UPV Audio Analyzer  Verify audio quality using PESQ®  and POLQA® algorithm Performance  Acoustic analysis: 3GPP TS 26.132 testing  Automated test of impacts of noise, fading, IP traffic impairment… with R&S Contest November 2012 | LTE Introduction | 279
  • LTE CallBox used for VoLTEAudio Quality Testing Scope of Audio Quality testing lAnalysis of the Audio Quality l„What is the Audio Quality of the VoLTE call a UE can perform?“ Audio lVerification of the audio quality with established Functional mechanisms like PESQ® and POLQA® algorithm Quality lAcoustic analysis of the signal according to 3GPP testing TS 26.132 Release 10 testing R&S®CMW500 LTE Call-box Performance testing R&S®UPV Audio Analyzer November 2012 | LTE Introduction | 280
  • NEW DAU Features Useful in LTEIntegrated IMS Server for Voice over IMS IMS Configuration Features: IMS infoscreen lLoopback mode or MediaEndpoint Connection for separate DL/UL Analysis lNarrowband Mobile infoscreen lWideband lDifferent Codec Rates lUseCase: l VoLTE or VoHSPA November 2012 | LTE Introduction | 281
  • CMW500 Speech VerificationAudio Quality analysis - Uplink l CMW500 establishes LTE and IMS connection to UE l Uplink verification: IMS Media PESQ/POLQA sequence server Server* RF from UPV is provided to UE and sent in uplink to CMW500; received VoIP USB Connection data is converted to analog (USB soundcard) and to microphone analyzed in UPV l Test focus: l UPV analyzes the audio quality PESQ/POLQA l Verification of separated uplinkPESQ/POLQA analysis *Media Server functionality: l De-packaging speech data from RTP l De-Coding digital speech data (e.g. AMR WB) November 2012 | LTE Introduction | 282
  • CMW500 Speech VerificationAcoustic tests according to 3GPP TS 26.132 l CMW500 establishes LTE and IMS connection to UE l DL or UL verification: 3GGP defined tests IMS Media performed by UPV using server Server* RF an artificial head l Test focus: USBLAN Connection l Acoustic tests according to Connection from loudspeaker 3GPP TS 26.132 to microphone l Verification of uplink and downlink 3GPP *Media Server functionality: TS26.132 l De-packaging speech data from RTP analysis l De-Coding digital speech data (e.g. AMR WB) November 2012 | LTE Introduction | 283
  • Final Test Setup for VoLTE Acoustic measurementsIntegrated IMS, integrated Audio Board and Codecs Integrated l CMW500 establishes LTE Audioboard and IMS connection to UE l establish a VoLTE call by using internal audio RF board and codecs IMS Audio server Codecs l Test focus: l Audio Quality Analysis PESQ/POLQA From loudspeaker to microphone l Acoustic tests according to 3GPP TS 26.132 with artificial head DL ULPESQ/POLQA analysis November 2012 | LTE Introduction | 284
  • Feature overview with 3.0.20l Support of different RATs VIDEOl Server for FTP, HTTP, IMS and DNS Calll IP Impairments VoIPl IP Logging Calll IMS Services SMS and VoIP SMSl PING Latencyl IPERF PING DNS FTP HTTP IPERF TP Streaming Latency IMS Application Data Application Unit IP-Logging IP IP-Impairments RAT LTE-FDD LTE-TDD GSM 1xEV-DO WLAN WCDMA November 2012 | LTE Introduction | 285
  • Radio Access Technologies today GERAN CDMA2K 1xEVDO UTRAN EUTRAN LTE coverage is not fully up from day one -> interworking with legacy networks is essential!!! November 2012 | LTE Introduction | 286
  • Voice calls in LTEl There is one common solution: Voice over IMS l -> also named Voice over LTE VoLTE or OneVoice initiative But…. What if IMS is not available at first rollout? -> interim solution called Circuit Switched Fallback CSFB = handover to 2G/3G -> or Simultaneous Voice on 1XRTT and LTE, SV-LTE = dual receiver What is if LTE has no full coverage? -> interworking with existing technologies, Single Radio Voice Call Continuity, SRVCC November 2012 | LTE Introduction | 287
  • 2G or 3G CS fallbackVoice call E-UTRAN MME IMSVoice over IMS is the solution,but IMS is maybe not available in the first network roll-out.Need for transition solution: Circuit Switched Fall Back, CSFB move the call to 2G or 3G November 2012 | LTE Introduction | 288
  • CSFB issues and questions Iu-ps SGSN Target cell UTRAN assigned or Gsselected by UE? Gb Uu GERAN S3 Iu-cs MSC Um A Server SGs LTE Uu S1-MME UE E-UTRAN MME Handover or Redirection?•Is it a handover command or a command to redirect to a new RAN ? i.e.the UE selects the target cell or the EUTRAN commands the target cell•Is there any information about the target RAN available (SysInfo)?•Is there a packet data connection PDN active or not?•Will the PDN be suspended or continued in the target RAN?•Will the UE re-initiate the PDN or continue? November 2012 | LTE Introduction | 289
  • CS fallback options to UTRAN and GERAN Feature group index, UE indicates CSFB support November 2012 | LTE Introduction | 290
  • CS fallback to 1xRTT 1xCS CSFB 1xRTT CS A1 1xRTT UE Access MSC A1 Tunneling of 1xCS IWS S102 is the messages between reference point 1xRTT MSC and UE S102 between MME and MME 1xCS interworking S1-MME S11 solution 1xCS Serving/PDN SGi E-UTRAN CSFB GW UE S1-U Tunnelled 1xRTT messages November 2012 | LTE Introduction | 291
  • CS fallback to 1xRTT November 2012 | LTE Introduction | 292
  • CS fallback - argumentsl E-UTRAN and GERAN/UTRAN coverage must overlapl No E-UTRAN usage for voicel No changes on EPS network requiredl Gs interface MSC-SGSN not widely implementedl Increased call setup timel No simultaneous voice + data if 2G network/UE does not support DTMl SMS can be used without CS fallback, via E-UTRAN November 2012 | LTE Introduction | 293
  • Why not CSFB?l Call setup delayl Call drop due to handover l Blind hand-over is used for CSFBl Data applications are interuptedl Legacy RAN coverage needed November 2012 | LTE Introduction | 294
  • Dual receiver 1xCSFB Circuit switched UE 1xRTT registration CDMA2000 cell eNB for LTE Packet switched EUTRAN registrationDual receiver 1xCSFB UEs can handle separate mobility andregistration procedures 2 radio links at the sametime. UE is registered to 2 networks, no coordination required.When CS connection in 1xRTT,dual receiver UE leaves EUTRAN! November 2012 | LTE Introduction | 295
  • SV-LTE: Simultaneous CDMA200 + LTE Circuit switched UE 1xRTT connection CDMA2000 cell eNB for LTE Packet switched EUTRAN connectionSimultaneous Voice UEs can handle 2 radio links at the sametime. UE is registered to MME and CDMA2K independently November 2012 | LTE Introduction | 296
  • OTT – over the top EUTRAN ApplicationUE Evolved nodeB S-GW P-GW PDN Evolved Packet Core Voice call as application, e.g. Skype, Google talk, … November 2012 | LTE Introduction | 297
  • OTT – over the top - arguments EUTRAN Application UE Evolved nodeB S-GW P-GW PDN Evolved Packet Core•Propietary solution, needs to be implemented in UE and AS•Already implemented in computer networks – known application•Support has to be accepted by operator•No Inter-RAT handover is possible November 2012 | LTE Introduction | 298
  • SMS transfer in LTEEncapsulate SMS in NAS Send SMS over IMS Control message-> Using IP protocol SMS over SG SMS over IMS EMM ESM User plane Radio Resource Control RRC Packet Data Convergence PDCP Radio Bearer Measurements Radio Link Control Control & RLC Logical channels Medium Access Control MAC Transport channels PHYSICAL LAYER November 2012 | LTE Introduction | 299
  • Single Radio Voice Call Continuity Problem: in first network roll-out, there is no full LTE coverage. How to keep call active? => SRVCC November 2012 | LTE Introduction | 300
  • Single Radio Voice Call Continuity VoLTE call eNodeB = EUTRAN Handover to UTRAN VoIP in PS mode NodeB = UTRAN Radio Bearer reconfiguration: PS to CS modetime Voice call in CS mode NodeB = UTRAN November 2012 | LTE Introduction | 301
  • Handover – what to discuss?UE reads GERAN cell(s)?SysInfo eNodeBUTRAN cell(s)? EUTRAN cellCDMA2K cell(s)? NW sends UE Redirection command? SysInfo of Target? Will the UE initiate the Handover command? change? -> re-selection Will the network initiate Mandatory the change? -> for UE redirection or handover supporting CSFB November 2012 | LTE Introduction | 302
  • Handover aspects – what to discuss?l Some keywords that appear – and to be clarified in next slides:l Handover?l Cell reselection?l Cell change order?l Redirection?l Network assisted cell change, NACC?l Circuit switched fallback, CS fallback? November 2012 | LTE Introduction | 303
  • Mobility between LTE and WCDMA/GSMRadio Access Aspects GSM_Connected CELL_DCH Handover E-UTRA Handover RRC_CONNECTED GPRS Packet transfer mode CELL_FACH CCO with optional CCO, CELL_PCH NACC Reselection URA_PCH Reselection Connection Connection Connection establishment/release establishment/release establishment/release Reselection E-UTRA Reselection GSM_Idle/GPRS UTRA_Idle RRC_IDLE Packet_Idle CCO, Reselection November 2012 | LTE Introduction | 304
  • Redirection to UMTS UE reads SysInfo eNodeBNodeB(s) EUTRAN cellUTRAN cell(s) RRC connection release message UE will search for UE with RedirectedCarrierInfo to suitable cell on UARFCN and initiate UTRAN Mandatory for UE CS connection supporting CSFB RRC connection release with redirection without SysInfo November 2012 | LTE Introduction | 305
  • Redirection to UMTS Rel. 9 featureUE readsSysInfo NodeB eNodeB Sys UTRAN cell Info EUTRAN cell RRC connection release message UE will go to indicated UE with RedirectedCarrierInfo to cell and initiate CS connection UTRAN e-RedirectionUTRA capability is set by UE RRC connection release with redirection with SysInfo November 2012 | LTE Introduction | 306
  • Redirection to GERAN eNodeBBTS(s) EUTRAN cellGSM cell(s) RRC connection release message UE will search for UE with RedirectedCarrierInfo to suitable cell on ARFCN and initiate CS GSM Mandatory for UE connection supporting CSFB RRC connection release with redirection without SysInfo November 2012 | LTE Introduction | 307
  • Redirection to GERAN Rel. 9 feature BTS(s) eNodeB Sys GSM cell(s) Info EUTRAN cell RRC connection release messageUE will go to indicated UE with RedirectedCarrierInfo to cell and initiate CS connection GSM e-RedirectionUTRA capability is set by UE RRC connection release with redirection with SysInfo November 2012 | LTE Introduction | 308
  • Handover to UMTS: Packet switchedhandover eNodeBNodeB(s) EUTRAN cellUTRAN cell(s) UE MobilityFromEUTRACommand messageUE will select target cell on UARFCN and with purpose indicator = handovercontinue PS connection to UTRAN EUTRAN contains targetRATmessagecontainer, = Inter-RAT info about target cell Packet Switched handover to UTRAN November 2012 | LTE Introduction | 309
  • Inter-RAT Handover to GERAN: cell change order PS connection will be suspended eNodeBBTS(s) EUTRAN cellGPRS cell(s) MobilityFromEUTRACommand message UE with purpose indicator = Cell Change Order UE will search for suitable cell on ARFCN to GPRS Mandatory and re-initiate PS for UE connection supporting CSFB Packet Switched cell change order to GPRS without NACC (network assisted cell change) November 2012 | LTE Introduction | 310
  • Inter-RAT Handover to GERAN: cell change order PS connection will be suspended BTS eNodeB Sys GPRS cell Info EUTRAN cell MobilityFromEUTRACommand message UE with purpose indicator = Cell Change Order UE will search forsuitable cell on ARFCN to GPRS Mandatory and initiate PS for UE connection supporting CSFB Packet Switched cell change order to GPRS with NACC (network assisted cell change) November 2012 | LTE Introduction | 311
  • Inter-RAT Handover to GERAN: handover PS connection will be handed over BTS eNodeB GPRS cell EUTRAN cell UE will search for MobilityFromEUTRACommand message suitable cell on ARFCN UE with purpose indicator = handover and continue PS to GPRS connection Mandatory for UE supporting CSFB Packet Switched handover to GPRS November 2012 | LTE Introduction | 312
  • LTE-RTT HandoverCircuit Switched Fallback, CSFB Overview November 2012 | LTE Introduction | 313
  • CS fallback to 1xRTT 1xCS CSFB 1xRTT CS A1 1xRTT UE Access MSC A1 Tunneling of 1xCS IWS S102 is the messages between reference point 1xRTT MSC and UE S102 between MME and MME 1xCS interworking S1-MME S11 solution 1xCS Serving/PDN SGi E-UTRAN CSFB GW UE S1-U Tunnelled 1xRTT messages November 2012 | LTE Introduction | 314
  • CS fallback to 1xRTT CSFB to 1xRTT MME CSFB Info eNodeB1xRTT cell(s) EUTRAN cell RRC connection release message UE will search for UE with RedirectedCarrierInfo to suitable cell on UARFCN and initiate 1xRTT Mandatory for UE CS connection supporting CSFBEnhancement: UE can pre-register in 1xRTT network to 1xRTT RRC connection release with redirection without SysInfo November 2012 | LTE Introduction | 315
  • CS fallback to 1xRTTenhanced 1xCSFB (e1xCSFB) Enhancement: UE can pre-register in 1xRTT network UE EUTRAN 1) Prepare for handover, search for HandoverFromEUTRAPreparationRequest 1xRTT Time flow UE EUTRAN 2) Info about 1xRTT -> tunnelled via ULHandoverPreparationTransfer S102 UE EUTRAN 3) Includes1xRTT channel assignment MobilityFromEUTRACommand November 2012 | LTE Introduction | 316
  • CS fallback to 1xRTTenhanced 1xCSFB (e1xCSFB) + concurrent HRPD handover Enhancement: UE can pre-register in 1xRTT network 1) Prepare for UE EUTRAN handover, search for HandoverFromEUTRAPreparationRequest 1xRTT + HRPD 2) Trigger 2 UE EUTRAN Time flowmessages with ULHandoverPreparationTransfer info about1xRTT + HRPD UE EUTRAN ULHandoverPreparationTransfer UE EUTRAN 3) Redirection to 1xRTT and handover to MobilityFromEUTRACommand HRPD November 2012 | LTE Introduction | 317
  • LTE-eHRPD Handover Overview November 2012 | LTE Introduction | 318
  • EUTRAN – eHRPD non-roaming i.e. US subscriber, connected To home network, leaves LTE coverage area November 2012 | LTE Introduction | 319
  • EUTRAN – eHRPD, roaming case i.e. European subscriber visiting US, connected to roaming network and leaving LTE November 2012 | LTE Introduction | coverage area 320
  • Mobility between LTE and HRPDRadio Access Aspects No handover to EUTRAN HRPD active to EUTRAN is always cell reselection (via RRC idle) November 2012 | LTE Introduction | 321
  • 3 Step Procedure Ability of pre- E-UTRAN needs registration is to decide, that indicated HO to HRPD on PBCCH is requiredUE attached Pre-registration HO preparation HO executionto E-UTRAN• Reduces time for cell re-selection or handover• Reduces risk of radio link failure Connection Request Traffic Channel Assignment issued by UE to command is delivered HRPD, HRPD prepares to UE, re-tune radio to for the arrival of the UE HRPD channel, acquire HRPD channel, session configuration November 2012 | LTE Introduction | 322
  • Video over LTETesting the next step in the end userexperience
  • IntroductionNetwork view Impact due to EPC / IMS l Packet delay l Packet jitter l Packet loss MME PCRF l … Node B SGW PGWImpact due to Internetl Multipath propagationl Speedl … Node B November 2012 | LTE Introduction | 324
  • IntroductionTesting real life conditions in the labl Main use cases from a test engineer (operator, manufacturer) perspective: l Exploring the performance of mobile equipment from the end user perspective l Measuring E2E throughput with realistic radio conditions l Evaluating mobility performance R&S®AMU200 Contest SW baseband fader provides simulates real life automation radio conditions and reporting capabilities R&S®CMW500 emulates LTE network CMW-PQAl Important aspect for end user perspective: Error free video reception November 2012 | LTE Introduction | 325
  • Video transmission over LTE The video processing chain and possible sources for video degradation • Encoding artifacts Impairments on the The decoder is usually the less (blocking) transmission link critical component. But in can cause loss of conjunction with the video • Video / audio delay information despite processor, errors during the • Buffer rules are active error conversion process (e.g. de- violated correction interlacing) are possible Transmission link (IP, cellular, broadcast, etc.) Encoder TX RX Decoder Video processor ReceiverUncompressed video Output on Redundant Restoring the video Scaling andSDI screen information (static information; i.e. the conversion to outputSMPTE249/292/424 image parts) and picture sequence format irrelevant data including redundant (details) is omitted data November 2012 | LTE Introduction | 326
  • Video transmission over LTETesting real life conditions in the lab PC Contest TC Control RF Video via MHL or HDMI November 2012 | LTE Introduction | 327
  • Video transmission over LTER&S®VTE Video Testerl Source, sink and dongle testing on MHL 1.2 interfaces and in the future also HDMI 1.4c, etc.l Realtime difference picture analysis for testing video transmissions over LTE R&S®VTE Video Testerl Combined protocol testing and audio/video analysisl Future-ready, modular platform accommodating up to three test modulesl Localized touchscreen user interfacel Integrated test automation and report generation November 2012 | LTE Introduction | 328
  • Summaryl Video and voice are important services gaining momentum for the fastest developing radio access technology ever - LTEl Beside LTE functionality, testing voice/video quality is essential to judge a good receiver implementation l R&S provides you with profound expertise and test solutions on both aspects l Complete LTE test portfolio ranging from early R&D via IOT and field testing until conformance and production l Supplier of a complete range of TV broadcasting transmission, monitoring and measurement equipment November 2012 | LTE Introduction | 329
  • There will be enough topics for future trainings Thank you for your attention! Comments and questions welcome! November 2012 | LTE Introduction | 330