Universal Wireless Communications 136 (UWC-136) is an evolutionary step for IS-136 based Time Division Multiple Access (TDMA). Its purpose is to provide future IMTS services to existing TDMA service providers and potential future TDMA service providers. UWC-136 is actually four TDMA radio systems in one. It supports the existing IS-136 TDMA Standard, the enhanced 30kHz IS-136 carrier (136+), the 200kHz 136 HS, and the 1.6MHz indoor 136 HS. Together these four components make up UWC-136. In this presentation we will focus on 136 HS. However, we will touch upon some of the characteristics of IS-136 and 136+ even though the are really considered second generation systems.
In this viewgraph we provide a brief review of IS-136 based Time Division Multiple Access (TDMA). Both 136 and 136+ are Frequency Division Duplex (FDD) systems with 30 kHz x 2 traffic channels (30 kHz forward link and 30 kHz reverse link). The raw channel rate for 136 is 48.6 kbps and the raw channel rate for 136+ is either 48.6 kbps or 72.9 kbps depending on the modulation scheme used. Different data rates also allow for different vocoders. 136 supports the IS-641A Algebraic Code Excited Linear Predictive (ACELP) vocoder. The ACELP vocoder is a 7.4 kbps vocoder. 136+ supports both the IS-641A vocoder and the US1 vocoder. The US1 vocoder is a 12.2 kbps vocoder. Both 136 and 136+ have 40 msec frame sizes and 6 times slots per frame in a Radio Frequency (RF) Channel, however, a user occupies two time slots per frame. Therefore, the effective number of timeslots per frame is three. 136+ support both voice and data simultaneously, however, if both voice and data are used the data must be transmitted in the Digital Control Channel (DCCH), Slow Associated Control Channel (SACCH,) or Fast Associate Control Channel (FACCH) This limits the types of data that can be sent to short messages and very low rate asynchronous data. Assuming a reuse factor of 7/21, 136, and 136+ require a minimum bandwidth of 21x 30kHz = 630kHz for the forward link and 630kHz for the reverse link. All handoffs in 136 and 136+ are Mobile Assisted Handoffs (MAHO). The following types of handoffs are supported. intra-cell and inter-cell multi-bearer radio and network originated analog voice channel to analog voice channel analog voice channel to 800MHz digital traffic channel 800 or 1900 MHz digital traffic channel to 800 or 1900 MHz digital traffic channel.
UWC-136 can operate in any band of frequencies between 500MHz and 2.5GHz. However, the proposal is based on operating in the US cellular or Personal Communication System (PCS) band and therefore the difference between the forward link and reverse link is 45MHz or 80MHz respectively. Other frequency spacings are possible, but would need to be investigated further. As shown in the above viewgraph, the bandwidths for 136 HS are substantially larger than the 30 kHz bandwidth required for 136 and 136+. The outdoor 136 HS requires a bandwidth of 200 kHz, which is the same bandwidth used for GSM. The indoor 136 HS requires a bandwidth of 1.6 MHz or 8 times more bandwidth than the outdoor version. By keeping the bandwidth of the indoor system a multiple of the outdoor system, RF planning and interoperability between the two system are made easier. Both the outdoor and indoor systems support Slow Frequency Hopping (FH). This will also make interoperating with GSM easier because GSM systems can also slow frequency hop. As seen above, UWC-136 meets the data requirements for IMT-2000 with data rates up to 2Mbps. The proposal had some concern over the IMT-2000 requirement to communicate with aircraft since currently cellular phones may not be operated on commercial aircraft. Of course 136 HS is designed to coexist with current systems especially 136 systems. The indoor version of 136 HS supports both an FDD and a Time Division Duplex (TDD) mode.
The above viewgraph shows one way of dividing the frequency band between 136HS and 136. 136 requires 30kHz channels and may require a 7/21 reuse pattern. The 7/21 frequency reuse pattern means that 21 sets of 30kHz channels are distributed among 7cells. This is shown in the lower half of the viewgraph above. Notice that there are 7 base stations with 3 sectors each shown in the figure. Each sector on the 7 base stations must have different 30kHz channels assigned to it. However, the next set of 7 base stations can reuse the same frequency pattern. Notice the the 136 HS uses a 1/3 reuse pattern, which mean that each sector on a three sectored base station has a different set of 200kHz channels on it and the next base station can reuse those same channels. 136 HS may also be operated with a reuse factor of one like CDMA if the load on each base station is not too great. A guard band is required between 136 and 136 HS. UWC-136 supports Dynamic Channel Allocation (DCA) which will automatically adjust the frequency plan for the additional channels and sites based on the desired quality of service. However, the procedure for DCA is not described in the proposal. In addition, DCA is not required when using the 1/3 reuse for 136 HS outdoor or indoor since each base station has the same set of frequencies. For larger spectrum deployments of these systems the same DCA procedures used for 136 and 136+ could be used for 136 HS.
Both the indoor and outdoor 136 HS support forward and reverse link power control. Power control for these systems is accomplished by sending signaling messages between the base station and mobile station. This means that the power control rate depends somewhat on the environment and has a minimum rate of the frame rate. Both systems also support spatial diversity through the optional use of two or more antennas at the base station and mobile station. The proposed 136 outdoor system just talks about having spatial diversity at the base station and mobile station. The proposed indoor system talks about two or more antennas and adaptive antennas at the mobile and base station. The 136 HS indoor and outdoor systems support the use of three different modulation schemes. Binary Offset Quadrature Amplitude Modulation (B-O-QAM), Quatenary Offset Quadrature Amplitude Modulation (Q-O-QAM), and Gaussian Minimum Shift Keying (GMSK). These modulation schemes will be discussed further on the next viewgraph. Several enhancements to the proposal are described. The proposal mentions that joint demodulation of the desired signal and the dominant interfering signal could lead to substantial interference suppression. In addition, the proposal mentions the use of optimized puncturing, turbo codes, longer constraint lengths on the convolution codes, and adjustable interleaver depth to improve link performance. Finally, the proposal talks about frame by frame fast power control to improve performance.
UWC-136 uses a total of 6 different modulation schemes. 136 uses /4 Differential Quadrature Phase Shift Keying ( /4-DQPSK). 136+ uses coherent Quadrature Phase Shift Keying (QPSK) and 8-ary Phase Shift Keying (8-ary PSK). 8-ary PSK requires a greater energy per bit to noise power per Hertz (Eb/No) than QPSK. Therefore QPSK is used in noisy environments and 8-ary QPSK is used where it can tolerate the noise levels. QPSK is also the modulation scheme used on the forward link of IS-95 based Code Division Multiple Access (CDMA). 136 HS can support three modulation schemes Binary Offset Quadrature Amplitude Modulation (B-O-QAM), Gaussian Minimum Shift Keying (GMSK), and Quatenary-Offset Quadrature Amplitude Modulation (Q-O-QAM). B-O-QAM is equivalent to Offset Quadrature Phase Shift Keying (OQPSK), which is the modulation scheme used on the reverse link of IS-95A based Code Division Multiple Access (CDMA) systems. GMSK has very good constant envelop characteristics and is used in GSM systems. We observe that the bandwidth of the outdoor 136 HS is 200kHz and one option for the modulation is GMSK. This makes the waveform very similar to that used by GSM.
New to CDMA: Inter-frequency handoff Save cost on transceiver costs.
Outer Loop: Receive signal, measure frame error rate, and request change in power. Open loop: Estimate power setting for the first time Closed loop: frame control basis
More complicated receivers for no synchronization
Biggest difference from cdmaOne: No discontinuous transmission Base stations are synchronized
Simultaneous on the right hand side Other carriers are interested in the simultaneous services Two rate sets (9.6kbps and 14.4kbps) for support of two different voice coders, keep it the same for the data rates.
Will always have 1.25 MHz carriers in multiples of the N allowed for the direct sequence channel width. Never have two multi-carrier channels because there is no N=2 for the direct sequence.
Chip rates are different from WCDMA
Shared - share paging and sync channels between IS-95 and cdma2000 Wideband - cdma2000
Improve data capacity through packetization: fast setup channel only used to transmit desired information
Cell sizes meant to be small Targeted toward indoor, city use Compatible to fit into GSM spectrum
Works on multiple of 9.6 Aggregation of codes, slots, and channels.
Each of the code words arrive at the basestation at the same time. All the handsets are adjusted to synchronization at the basestation site. Transferring cost to handsets with adjustments but keeping BS cost low. Not perfect because of multipath problems
Two simultaneous communications on different frequencies f1 and f4. MAHO mobile assisted handoff
CDMA I is a lot like cdma2000 CDMA II is a lot like W-CDMA
W-CDMA/Japan similar to UTRA
Compatible with UTRA Don’t really need an air interface for satellite Keep international standards is in the global roaming HEO - High Earth Orbit
Not a simple whip antenna ATM-like- cell-switching
3 g seminar 2g 3g air interfaces 1-7-00
2G and 3G Air Interfaces
Air Interfaces Outline Definitions Third Generation Terrestrial Radio – Frequency Division Duplex Systems (FDD) – UWC-136 – Time Division Duplex (TDD) – UTRA – Frequency Division Multiple – cdma2000 Access (FDMA) – TD-CDMA – Time Division Multiple Access – DECT (TDMA) – Other 3G WCDMA Systems – Code Division Multiple Access CDMA I (CDMA) CDMA II Second Generation Radio Systems W-CDMA/Japan – US TDMA WCDMA/NA – CDMA WIMS W-CDMA – GSM Some 3G Satellite Radio Systems – SW-CDMA & SW-CTDMA – ICO Satellite RTT – Horizons System RTT
Frequency Division Duplex (FDD) For wa rd Lin kF Re req ver uen se cy Lin kF r eq uen cy In FDD Information From the Handset to the Base Station Is Carried on One Frequency and Information From the Base Station to the Handset Is Carried on Another
Time Division Duplex (TDD) Re ver se Tim Link eS lot For Tim ward e S Link lot In TDD Information From the Handset to the Base Station Is Transmitted at One Time on One Frequency and Information From the Base Station to the Handset Is Transmitted at Another Time on the Same Frequency
Advantages and Disadvantages of TDD Advantages of TDD Over FDD – More Efficient for Asymmetric Data – Reverse Link and Forward Link Propagation Conditions Are Identical Forward Link Beamforming Can Be Base on Reverse Link – Less Complex RF Transceiver Disadvantages of TDD Over FDD – More Delay – Limited Communications Distance
Frequency Division Multiple Access (FDMA) Each User Occupies a Different Frequency Channel Channel N Channel 2 Channel 4 Channel 1 Channel 3 Channel 5 Time Frequency
Time Division Multiple Access (TDMA) Each User Occupies a Time Slot TDMA Is Really FDMA With Each Frequency Channel Divided Into Time Slots TS3 TS3 TS3 TS3 TS3 TS3 Time TS2 TS2 TS2 TS2 TS2 TS2 TS1 TS1 TS1 TS1 TS1 TS1 Frequency
Code Division Multiple Access (CDMA) Each User Has a Unique Code CDMA Is Really FDMA With Multiple Users, Identified by Codes, Sharing Each Frequency Channel User 1 User 1 Time User 2 User 2 User 3 User 3 User N User N Frequency
US TDMA Highlights TDMA ≡ Time Division Multiple Access Improved Capacity Over AMPS Backward Compatible With AMPS Incremental Migration From AMPS to D-AMPS Use of Same Frequency Band by AMPS and D-AMPS Acceptable Voice Quality Support of New Services Support of Dual Mode (AMPS/TDMA) Phones Improved Voice Privacy Improved Fraud Control (Use of Authentication) US TDMA Carriers – AT& T Wireless (800 and 1800MHz) – Southwestern Bell Mobile Systems (800 and 1800MHz) – Cellcom of Israel (800MHz) – Etc.
Control Channels in D-AMPS AMPS 800MHz D-AMPS 800/1800MHzIS-54b:Analog control channelsShared with ampsIS-136:Analog Control Channels: AmpsDigital Control Channels: D-amps J-STD-009,010,011: Analog Control Channels Shared With Amps (1800MHz)
US TDMA Waveform TS1 40m TS2 s TS3 TS4 30k TS5 Hz TS6 3 Users Per Frequency Channel Π/4-DQPSK I π/4-DQPSK Modulation Q
US TDMA Specifications Multiple Access TDMA Duplex Scheme FDD Chip Rate Not Applicable Frame Length 40ms Bandwidth 30kHz Data Modulation π /4 - DQPSK Spreading Modulation Not Applicable Channel Coding Convolutional Power Control None Diversity BS Antenna Selection Diversity
US TDMA Interesting Features IS-136 Versus IS-54 – Digital Control Channels Added for TDMA New Set of Frequencies Indicator Field Added to Inform MS of Location of Control Channels – Coded Digital Verification Color Code (CDVCC) Added to Control Channels Frequency Reuse Same As AMPS F2 F7 F3 F1 F6 F4 F5 7/21 Reuse pattern
GSM Highlights GSM ≡ Global System for Mobile Communications Design Goals for GSM – One Standard for Europe - Roaming Among Countries – Open Interfaces - Almost All – Digital With Frequency Reuse of 4 – Rich Feature Set Similar to ISDN – Authentication and Voice Privacy – Smart or SIM Cards Air Interface Specifications – GSM – DCS-1800 – ANSI J-STD-007 or PCS 1900 Air Interface Specification for 1.8 to 2.0GHz Frequency Hopping Time Division Multiple Access (TDMA) for Personal Communication System
cdmaOne Highlights cdmaOne ≡ Code Division Multiple Access Based on IS-95 Air Interface Standard Air Interface Standards – IS-95 800MHz Standard – J-STD-008 1900MHz Standard All Base Stations Transmit on the Same Frequency All Mobile Stations Transmit on the Same Frequency Soft Handoff: Multiple Base Stations (or Sectors) Send the Same Signal to a Single Mobile Station Handsets Have Special Receivers Called Rake Receivers That Combine Multipath or Multiple Copies of the Same Signal Approximately 6x Improvement Per Channel Over AMPS Capacity
cdmaOne Channels Pilo t Syn c Pag ing Acc ess Tra ffic 1.25 M Hz
cdmaOne Specifications Multiple Access CDMA Duplex Scheme FDD Chip Rate 1.2288Mcps Frame Length 20ms Bandwidth 1.25MHz Data Modulation BPSK Spreading Modulation Fwd: QPSK, Rvr: OQPSK Channel Coding Convolutional Power Control Fwd Rvr: Open loop and closed loop. Closed loop at 800Hz Diversity BS Antenna Selection Diversity Rake receiver
cdmaOne Soft Handoff Example: – Three Base Stations Sending the Same Information to the Mobile Station – Three Base Stations Receiving the Same Information From the Mobile Station
What is UWC-136? Evolution of Today’ s TDMA (IS-136) Universal Wireless Communications (UWC) - 136 UWC-136 IS-136 136+ 136 HS
IS-136 and IS-136+ Highlights 136 TDMA Characteristics – Based on TIA/EIA IS-136 – FDD – 30kHz Bandwidth Per Traffic Channel – Maximum Data Rate: ≤ 9.6kbps Using One Timeslot – Supports Several Methods of Handoff – Supports IS-641A ACELP Vocoder – Minimum Required Bandwidth for 7/21 Reuse Is 630kHz by 2 136+ TDMA Characteristics – Simultaneous Voice and Data – 30kHz Bandwidth Per Traffic Channel – Supports IS-641 and US1 Vocoder – Maximum User Data Rate: ≤ 14.4kbps using One Timeslot – Minimum Required Bandwidth for 7/21 Reuse Is 630kHz by 2 – Supports Discontinuous Transmission (DTX) – Minimum Required Bandwidth for 7/21 Reuse Is 630kHz by 2
136 HS Highlights Supports Mulitband Operation From 500MHz to 2.5GHz Can Be Deployed in a Minimum of 1MHz of Spectrum Coexist With Existing Second Generation Systems FDD for 136 HS Outdoor and FDD or TDD for 136 HS Indoor 136 HS Services Supported by 136 and 136+ Control Channels Slow Frequency Hopping Option Minimum Data Rate Requirements – Macrocellular Pedestrian (3km/hr): > 384kbps Low Speed Vehicle (≤100km/hr): > 384kbps High Speed Vehicle (100-500km/hr): > 144kbps – Micrcellular/indoor Pedestrian (≤3km/hr): > 2048kbps UWC-136 Bandwidth Requirements – 136 HS Outdoor 200kHz – 136 HS Indoor 1600kHz
UWC-136 Specifications UWC-136+ UWC-136HS UWC-136HS Outdoors Indoor Multiple Access TDMA TDMA TDMA Duplex Scheme FDD FDD TDD Chip Rate Not Applicable Note Applicable Not Applicable Frame Length 40ms 4.615ms 4.615ms Bandwidth 30kHz 200kHz 1600kHz Data Modulation π /4 DQPSK 8PSK Q-O-QAM π /4 QPSK GMSK B-O-QAM 8PSK Time Slots 6 8 64/16 Spreading Modulation Not Applicable Not Applicable Not Applicable Channel Coding Convolutional Convolutional, Turbo Convolutional, Turbo Power Control None Fwd&Rvr Fwd&Rvr Time slot Time slot Diversity Antenna Antenna Antenna Smart Antenna Smart Antenna
136 HS Frequency Planning Coexistence of 136 HS and 136 Guardband 200kHz 30kHz E1 E2 E3 D1 D2 D3 D4 D5 D6 D7... Potential Cell Plan D2 D5 D16 D19 Base Station D9 D12 D4 D1 D7 D18 D15 D21 D11 D8 D14 D6 D3 D20 D17 D13 D10
UWC-136HS Forward an Reverse Link Features 136 HS Outdoor – Forward and Reverse Link Power Control on a Time Slot Basis Via Signaling Messages – Antenna Diversity With Two Receiver Chains and Antennas – 8-PSK and GMSK Modulation 136 HS Indoor – Forward and Reverse Link Power Control on a Time Slot Basis Via Signaling Messages – Multiple Antennas or Adaptive Antennas – B-O-QAM and Q-O-QAM Modulation Enhancements – Inter-cell Interference Suppression Via Adaptive Array Antennas and Joint Demodulation of Co-channel Signals – Fast Power Control on Frame by Frame Basis – Improved Channel Coding Using Optimized Puncturing, Turbo Codes, Etc.
UWC-136 Modulation Schemes 136 136+ 136HS Outdoors 136HS Indoors I I I I Q-O-QAM π/4-DQPSK π/4-DQPSK 8-ary PSK Q Q Q Q I I I I π/4 -QPSK π/4 -QPSK GMSK B-O-QAM Q Q Q Q I 8-ary PSK Q
UTRA Highlights UTRA ≡ UMTS Terrestrial Radio Access ETSI SMG2 Proposal to ITU In the Paired Band (FDD - Frequency Division Duplex) of UMTS the System Adopts the Radio Access Technique Formerly Proposed by the W-CDMA Group In the Unpaired Band (TDD - Time Division Duplex) the UMTS System Adopts the Radio Access Technique Proposed Formerly by the TD-CDMA Group Variable Spreading Factor (VSF) and Multicodes Used for Variable Data Rates Handoff to GSM
UTRA Multiple Data Rate Support Variable Spreading Factor (VSF) in a Code for Multi-rate Data Services Multicode Scheme for Higher Data Rate Pilot Code 0 Rchip R/M PN Code Spreading SFmin = 8(RL) Factor = 16 (FL) Code 1 Traffic Rsymbol Max/2j R bps R/M Code 2Variable Spreading Factor R/M Code N Multi-code
UTRA Inter-Frequency Handoff The Downlink Is Slotted So That a Single Mobile Receiver Can Make Measurements on Other Frequencies When a Frame Is Slotted, It Is Transmitted at a Higher Power to Maintain a Constant Quality (BER or FER) When the Processing Gain Is Lowered. Tf Idle period available for interfrequency measurements When Sending High Data Rate Services Where Changing the Processing Gain Is Not Possible, Some Frames Are Compressed With a Lower Processing Gain for That Frame. Compressed transmission during one interleaver span
cdma2000 Highlights Direct Sequence and Multi-carrier Waveform Options on Forward Link Direct Sequence and Multi-carrier Waveforms May Employ Spatial Diversity Forward and Reverse Link Fast Power Control Auxiliary Pilots Provided for Antenna Array Applications 5 and 20 Millisecond Frame Lengths Utilize Turbocodes Coherent Reverse Link Using a Reverse Link Pilot Forward Link Fast Power Control Reverse Link Continuous Transmission – cdmaOne Discontinuous Transmission Base Stations Are Synchronized Via GPS
cdma2000 Frequency Plan Two options for using Bandwidth – Multi-Carrier (Forward Link Only) – Direct Sequence1.25MHz 1.25MHz 1.25MHz 1.25MHz 1.25MHz 1.25MHz 1.25MHz 625kHz Guardband Multi-Carrier1.25MHz 1.25MHz 1.25MHz 1.25MHz 1.25MHz 1.25MHz 1.25MHz Direct Sequence
cdma2000 Specifications Multiple Access FDD: DS-CDMA TDD: T/CDMA Duplex Scheme FDD/TDD Chip Rate 1.2288Mcps x N N=1,3,6,9,12 Frame Length 20/5ms Bandwidth 2.5/5/10/15/20MHz Data Modulation Fwd Link: QPSK Rvr Link: BPSK Spreading Modulation Fwd Link: QPSK Rvr Link: QPSK Channel Coding Convolutional, Turbo Power Control Closed, open, and outer loop at 800/sec FDD and 800/sec TDD
cdma2000 - Two Phases cdma2000 Phase 1 – 1.25MHz Channel With Enhanced Coding and Signal Processing (N = 1) – Physical Layer Capacity Improvements With Minimal Modifications to cdma2000 Base Stations – Higher Data Rates Via Improvements in Physical Layer – Data Capacity Improvements Via Enhanced Medium Access Control (MAC) Layer Quality of Service (QoS) Capabilities cdma2000 Phase II – Full IMT-2000 Compliance – Full Packet and Circuit Data Capability up to 2Mbps – Full MAC Layer QoS Capabilities
TD-SCDMA Highlights TD-SCDMA ≡ Time Division - Synchronous Code Division Multiple Access China CWTS Proposal to ITU Deployment Areas Will Be Medium and Large Cities Compatibility With 2G, Especially GSM in China High User Density Cell Sizes < 2km Environment: – Indoor – Outdoor to Indoor – Pedestrian
TD-SCDMA Variable Data Rate Basic Rate (9.6kbps), to Provide Higher Data Rate: – Aggregate Multiple Time Slots – Aggregate Multiple Code Channels – Use an Adaptive TDD Scheme (for Asymmetric Data) – Use a Higher Order Modulation Scheme (16QAM) – Use Multiple Frequency Carriers To Provide Low Speed Data (for Example, 4.8kbps) Service, a Simple Bit Repeating Scheme Can Be Used
What is SCDMA? Synchronous Code Division Multiple Access (SCDMA) Definition – Signals From the Mobiles Will Be Synchronous at the BS Code Channel 1 Advantages Code Channel 2 – All CDMA Code Channels Will Be Orthogonal Reducing Co-channel Base Code Channel 3 Interference Station – Higher Capacity – Simplified Hardware and Lower Cost Code Channel N
TD-SCDMA Specifications Multiple Access TDMA/CDMA Duplex Scheme TDD Chip Rate 1.136Mcps Frame Length 5ms Bandwidth 1.4MHz Data Modulation DQPSK/16QAM Spreading Modulation BPSK Channel Coding Convolutional Power Control Reverse link: open and closed 200/s Diversity 8 element smart array
TD-SCDMA Time Slot Structure TS u 0 TS 5ms u 1 TS d 0 TS d 1 TS d 2 TS 1.4M d 3 TS Guard band Hz d 4 TS u 0 TS u 1 Total 8 Time Slots (TSs) With 16 Channels Per TS Walsh Codes Separate Users Within a TS
DECT Highlights DECT ≡ Digital Enhanced Cordless Telecommunications ETSI Proposal to ITU Data Transmission Rates up to 2.88Mbps Wireless Relay Stations Coexistence of Uncoordinated Installations on the Same Frequency Bands Access to Different Systems by the Same Handset – GSM – ISDN – Data Networks DECT Authentication Module (DAM) – 128 Bit User Authentication Key – Cipher Generated During Authentication – 64 Bit Cipher Key
DECT Tx 0-5m Tx s 5-10 m s Tx 0-5m Tx s Rx Tx Rx 5-10 1.72 m s Rx 8M H Tx z Tx Symmetric Connection Asymmetric Connection
DECT Seamless Hand-off Base Base Station Station 0 0f1 12 12 11 11f4 23 23
Other 3G WCDMA Systems - Page One CDMA I ≡ Code Division Multiple Access I – South Korea TTA Proposal to ITU – Transmission Limitation for Inter-frequency Handoff Limit the Data Transmission on the Forward Link to Find Other Frequencies Without Sacrificing Link Performance – Synchronous Reverse Link Reverse Link Synchronization Using Time Alignment Command – Synchronous CDMA System Synchronous Cells Optional Asynchronous Mode Under Progress CDMA II ≡ Code Division Multiple Access II – South Korea TTA Proposal to ITU – Asynchronous Inter-BS Operation W-CDMA/NA ≡ Wideband Code Division Multiple Access / North America – USA T1P1 Contribution to ITU – FDD: No Inter-BS Synchronization TDD: Inter-base Station Synchronization
Other 3G WCDMA Systems - Page Two W-CDMA/Japan ≡ Wideband Code Division Multiple Access / Japan – Japan Association of Radio Industries and Businesses (ARIB) Proposal to ITU – FDD and TDD Modes FDD Does Not Require Accurate Inter-base Station Synchronization TDD Requires Accurate Inter-base Station Synchronization – Forward and Reverse Link Pilots Forward Link Pilot is a Separate Code for FDD Mode Reverse Link Pilot is I/Q Multiplexed for FDD Mode Forward and Reverse Link Pilots are Time Multiplexed for TDD Mode WIMS-WCDMA ≡ Wireless Multimedia and Messaging Services (WIMS) W-CDMA – No Inter-BS Synchronization Required
Other 3G WCDMA Air Interface Specifications-One CDMA I CDMA II W-CDMA/JapanMultiple Access DS-CDMA DS-CDMA FDD:DS-CDMA TDD:T/CDMADuplex Scheme FDD FDD FDD/TDDChip Rate 0.9216/3.6864.14.7456Mcps 1.024/4.096/8.192/16.384Mcps 1.024/4.096/8.192/16.384McpsFrame Length 10ms 10ms 10msBandwidth 1.25/5/10/20MHz 1.25/5/10/20MHz FDD: 1.25/5/10/20MHzData Modulation Fwd Link: QPSK Fwd Link: QPSK Fwd Link: QPSK Rvr Link: BPSK Rvr Link: BPSK Rvr Link: FDD: Dual channel QPSK TDD: QPSKSpreading Modulation Fwd Link: QPSK Fwd Link: QPSK Fwd Link: QPSK Rvr Link: OCQPSK Rvr Link: OCQPSK/CQPSK Rvr Link: QPSKChannel Coding Convolutional, outer Reed-Solomon Convolutional, Turbocodes Convolutional, Turbo codingPower Control Fwd link: closed 1600/sec Fwd link: closed 1600/sec and outerFDD: Closed, open, and outer loop at 1600/sec Rvr link: open and closed 1600/s Rvr link: open and closed 1600/s TDD: Closed at 800/secDiversity Rake, antenna diversity, Rake, antenna diversity, Rake, BS antenna diversity time switched Tx on Fwd Link time switched Tx on Fwd Link optional MS antenna diversity
Satellites: SW-CDMA & SW-CTDMA Why WCDMA for Satellites? – Full Frequency Reuse Easing Resource Allocation – Softer Handoff – Suitable for Interference Mitigation (MUD) Two European Radio Transceiver Technologies (RTT) Proposals: – SW-CDMA For Global Systems (Low Earth Orbit (LEO)/medium Earth Orbit(MEO)) Adaptation of the Terrestrial ETSI UTRA/ARIB W-CDMA Proposals to the Satellite Environment – SW-CTDMA For Regional Systems (HEO/GEO) Hybrid Solution Found Particularly Attractive for Regional Systems (HEO/GEO Orbits) Some Commonality With ETSI UTRA Combines CDMA and TDMA Advantages
SW-CDMA & SW-CTDMA Specifications SW-CDMA SW-TCDMAMultiple Access DS-CDMA Rvr: W-O-C/TDM Fwd: W-QS-C/TDMADuplex Scheme FDD FDD or F/TDDChip Rate 4.096Mcps (2.048Mcps option) 4.096Mcps (2.048Mcps option)Frame Length 10ms (20ms option) 20msBandwidth 5MHz (2.5MHz as option) 5MHz (2.5MHz as option)Data Modulation Fwd: QPSK (BPSK low data rate) QPSK or Dual BPSK Rvr: Dual BPSKHigh Power Paging Yes YesChannel Coding Convolutional, outer Reed-Solomon Convolutional, outer Reed-SolomonPower Control Open loop for RACH, Open loop for RACH, Closed loop based on SINR+FEC Closed loop based on SINR+FEC 100-400Hz update rate 100-400Hz update rate
Satellites: Horizons System RTT System Parameters: – TDMA/FDM Multiple Access Scheme 200 kHz Channels, Reservation Based Slot Allocation – Bandwidth Efficient Modulation and Coding 16-QAM, Turbo Coding – Bandwidth on Demand Capability ATM-like Cell-switching Protocol Use of Standard PC Communication Applications – Compatible With Industry Standard Modem Interfaces Service Compatibility, Roaming With Terrestrial IMT- 2000 High Power GEO Mobile Satellites for 2002 Service Laptop (144kbps)