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Wireless Communications & Spread Spectrum Design

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Wireless Communications & Spread Spectrum Design Course Sampler

Wireless Communications & Spread Spectrum Design Course Sampler

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    Wireless Communications & Spread Spectrum Design Wireless Communications & Spread Spectrum Design Presentation Transcript

    • Professional Development Short Course On: Wireless Communications & Spectrum Design Instructor: Scott R. Bullock ATI Course Schedule: http://www.ATIcourses.com/schedule.htm ATI's Wireless Communications: http://www.aticourses.com/wireless_communications_spectrum_design.htm
    • Wireless Communications & Spread Spectrum Design March 24-26, 2009 Beltsville, Maryland $1490 (8:30am - 4:00pm) Course Outline quot;Register 3 or More & Receive $10000 each Off The Course Tuition.quot; 1. Transceiver Design. dB power, link budgets, system design tradeoffs, gains/losses, Signal-to-Noise, Probability of Error, Bit Error Rate, Eb/No, link margin, Summary tracking noise and signal level through a complete system, effects and advantages of using spread This three-day course is designed for wireless spectrum techniques. communication engineers involved with spread 2. Transmitter Design. Various types and system spectrum systems, and managers who wish to enhance designs of spread spectrum transmitters, PSK, MSK, their understanding of the wireless techniques that are QAM, OFDM, Other, Pseudo-Random code generator, being used in all types of communication systems and multiple access TDMA/CDMA/FDMA, antenna sizing, products. It provides an overall transmit/receive, local oscillator, upconverters, look at many types and sideband elimination, power amplifiers, standing wave advantages of spread ratios. spectrum systems that are designed in wireless systems 3. Receiver Design. Dynamic range, image today. This course covers an rejection, limiters, minimum discernable signal, intuitive approach that provides superheterodyne receivers, importance of low noise a real feel for the technology, amplifiers, 3rd order intercept point for intermodulation with applications that apply to products, two tone dynamic range, tangential both the government and sensitivity, phase noise, mixers, spurious signals, commercial sectors. Students filters, A/D converters, aliasing and anti-aliasing filters, will receive a copy of the digital signal processors DSPs. instructor's textbook, Transceiver and Systems Design 4. Automatic Gain Control Design & Phase Lock for Digital Communications. Loop Comparison. AGCs, linearizer, detector, loop filter, integrator, using control theory and feedback systems to analyze AGCs, PLL and AGC comparison. Instructor 5. Demodulation. Demodulation and despreading Scott R. Bullock, P.E., MSEE, specializes in Wirelss techniques for spread spectrum systems, pulsed Communications including Spread Spectrum Systems matched filters, sliding correlators, pulse position and Broadband Communication Systems for both modulation, CDMA, coherent demod, despreading, government and commercial. He holds numerous carrier recovery, squaring loops, Costas and modified patents in communications and published several Costas loops, symbol synch, eye pattern, inter-symbol articles in various trade magazines. He was active in interference, phase detection, Shannon' s limit. establishing the data link standard for GPS SCAT-I 6. Basic Probability and Pulse Theory. Simple landing systems and developed spread spectrum approach to understanding Probability, Gaussian landing systems for the government. He is the author of process, quantization error, probability of error, bit error two books, Transceiver and System Design for Digital rate, probability of detection vs probability of false Communications & Broadband Communications and alarm, error detection and correction, digital pulsed Home Networking, Noble Publishing. He has published systems, pseudo-random codes for spread spectrum numerous technical articles, is an adjunct professor at systems. ITT and a guest lecturer for Polytechnic University on 7. Multipath. Specular and diffuse reflections, Direct Sequence Spread Spectrum and Multiple Access Rayleigh criteria, earth curvature, pulse systems, Technologies. vector and power analysis. 8. Improving the System Against Jammers. Burst What You Will Learn jammers, digital filters, adaptive filters simulations and actual design results, quadrature method to eliminate • How to perform link budgets for types of spread unwanted sidebands, orthogonal methods to reduce spectrum communications? jammers, types of intercept receivers. • How to evaluate different types of wireless 9. Global Navigation Satellite Systems. Basic communication transceivers? understand of the Global Positioning System GPS and • What methods are used for spread spectrum the spread spectrum BPSK modulated signal from modems, multiple access, OFDM, error detection space, Satellite transmission, signal structure, GPS / correction for digital communication systems? receiver, errors, narrow correlator, selective availability • What is multipath and how to reduce multipath SA, carrier smoothed code, Differential DGPS, Relative and jammers? GPS, widelane/narrowlane, carrier phase tracking • What is a Global Positioning System? KCPT, double difference. • How to solve a 3 dimension Direction Finding 10. DF & Interferometer Analysis. Positioning and system using interferometry? direction finding using a simpified interferometer From this course you will obtain the knowledge analysis, direction cosines, basic interferometer and ability to evaluate and develop the system equation, three dimensional approach, antenna design for wireless communication digital position matrix, coordinate conversion for moving transceivers including spread spectrum systems. baseline. Register online at www.ATIcourses.com or call ATI at 888.501.2100 or 410.956.8805 Vol. 95 – 43
    • e e at at lic l ia om lic up er .c up at D es D IM ot rs ot N om AT ou N o Ic o D .c • AT l • D l ia www.ATIcourses.com es te l• er rs a ia w. a ic at om er w ri ou pl M w ate .c at Ic u TI D es M M Boost Your Skills •A ot rs TI 349 Berkshire Drive I AT w. N ou A te Riva, Maryland 21140 AT with On-Site Courses w Do Ic te • .c ca Telephone 1-888-501-2100 / (410) 965-8805 te om es li ca l• om a rs up Tailored to Your Needs Fax (410) 956-5785 w .c lic ia w. li ou D Email: ATI@ATIcourses.com w up er es up AT Ic ot at wD rs D AT N M The Applied Technology Institute specializes in training programs for technical professionals. Our courses keep you ot ou ot o current in the state-of-the-art technology that is essential to keep your company on the cutting edge in today’s highly N I Ic N w. D AT competitive marketplace. Since 1984, ATI has earned the trust of training departments nationwide, and has presented o AT Do l• D on-site training at the major Navy, Air Force and NASA centers, and for a large number of contractors. Our training ia l• increases effectiveness and productivity. Learn from the proven best. w. • er w ial ia w at er w er For a Free On-Site Quote Visit Us At: http://www.ATIcourses.com/free_onsite_quote.asp IM at at IM AT IM For Our Current Public Course Schedule Go To: http://www.ATIcourses.com/schedule.htm w AT AT
    • Digital vs. Analog Comms Digital System Digital 5V 5V PSK, FH, etc. Demod A/D Mod Sampler D/A 5V analog = Digital 101 LO LO Digital 101 = 5V analog Perfect Reconstruction of the Digital Waveform Assuming No Bit Errors Analog System AM/FM etc Demod Mod LO LO 1 Analog Analog + Noise Bullock Engineering Research Copyright 2008
    • Digital Modulation 2 Bullock Engineering Research Copyright 2008
    • FSK and MSK Spectrums MSK Reduce Frequency Separation or Increase the Frequency Minimum Shift Key Rate - MSK 3 Bullock Engineering Research Copyright 2008
    • Continuous Phase - Phase Shift Keying CP-PSK Sinusoidal transitions from one phase state to another • No zero crossing, No AM • Remains at a phase state for a period of time • Used for packet radio and other burst type systems • Minimum Spectral Re-growth due to non-linearities • +90 +45 +135 0 R 0,0 Q Channel 1,0 R 180 I Channel 0 1 R R Q 1,1 1 0,1 -135 -45 -90 4 Bullock Engineering Research Copyright 2008
    • Spectral Re-growth Output of Modulator Filtered Output Sidelobes Reduced Spectral Re-growth (Sidelobe Regeneration) 5 Bullock Engineering Research Copyright 2008
    • Practical Digital Waveform Impulse Response Ideal filter is the Sinx/x which is impossible to build These filters approx. this ideal filter Sinx/x Raised Cosine Raised cosine squared MSK Gaussian Filter 6 Bullock Engineering Research Copyright 2008
    • Direct Sequence Spread Spectrum Jammer Fast PN Signal Code Jammer Spread Spectrum Signal Signal Spread Spread Spectrum Spectrum Spreader Receiver Fast PN Code Jammer Signal Filter Signal Spread Jammer Spectrum despreader 7 Bullock Engineering Research Copyright 2008
    • FH Spread Spectrum Jammer PN Hopping Spread Spectrum Signal Signal Spread Spectrum Signal Synthesizer Jammer Spread Spread Spectrum Spectrum Spreader Receiver PN Spread Spectrum Signal Spread Spectrum Jammer Dehopping Jammer Signal Synthesizer Filter Spread Spectrum despreader 8 Bullock Engineering Research Copyright 2008
    • Multiple User Techniques System 1 System 2 System 3 1 2 3 1 2 3 time a. Time division multiple access . Code 1 System 1 System 2 Code 2 System 3 Code 3 b. Code division multiple access. f1 f2 f3 Frequency System 1 System 2 System 3 9 c. Frequency division multiple access. Bullock Engineering Research Copyright 2008
    • Costas Loop Signal 1 Signal 2 10 Bullock Engineering Research Copyright 2008
    • OFDM Spectrum 1.2 1 Amplitude 0.8 Channel 2 0.6 Channel 3 0.4 Channel 1 0.2 0 -10 -5 0 5 10 Frequency 11 Bullock Engineering Research Copyright 2008
    • Chapter 3 The Receiver Superheterodyne To Digital Processor Image T/R Power A/D IF BPF LPF IFAmp Limiter LNA Reject Switch Divider Converter Filter LO AGC LO Transmitter 12 Bullock Engineering Research Copyright 2008
    • Phase Noise, Log-Log Scale Short term frequency/phase instability Random walk FM 1/(f*f*f*f) So(f) dBc Flicker FM 1/(f*f*f) So(f) = power spectral density white FM 1/(f*f) (radians2/Hz) dBc/Hz Flicker noise 1/f white noise f 1 10 100 1 kHz 10 kHz Frequency 1/(f*f*f*f) = close to carrier, difficult to measure, vibration, shock, temperature, environmental. 1/(f*f*f) =, observable in high quality oscillators, masked in low quality oscillators, not fully understood, physical resonance mechanism or actual parts in the oscillator. 1/(f*f) = common in passive-resonator like cesium and rubidium standards. 1/(f) = transistors, amplifiers, etc., noisy electronics, LNA helps. f = produced like the 1/f noise, stages of amplification is mainly responsible, broadband noise. 13 Bullock Engineering Research Copyright 2008
    • Group Delay Linear Receiver Constant Group Delay ISI Dispersion Non- Linear Receiver Non-Constant Group Delay 14 Bullock Engineering Research Copyright 2008
    • Group Delay Compensator Filter Response ______ Constant Group Delay Filter Group _______ Delay Group Delay ______ Compensator 15 Bullock Engineering Research Copyright 2008
    • Aliasing ts ts ts ts ts Sample points in time Waveform is sampled at the Nyquist rate Estimated Frequency Waveform does not meet Nyquist criteria Alias frequency produced by under-sampling the high frequency 16 Bullock Engineering Research Copyright 2008
    • Control Theory Analysis and Root Locus Plot 17 Bullock Engineering Research Copyright 2008
    • AGC/PLL Comparison V/dB filter DC offset gain 1/S dB/V dBm + dBm Kd F(s) Threshold Integrator Ko Kc - dB Amp control curve a. AGC control system analysis block diagram. V/phase filter no offset gain phase/V phase phase + error Threshold Ko/S Kd F(s) Kc =0 - VCO control curve phase b. PLL control system analysis block diagram. 18 Bullock Engineering Research Copyright 2008
    • Bode Plot for Negative Feedback Systems +20dB Gain 0dB -10 dB -1000 Phase -1800 -2700 Frequency (log scale) Instability & oscillation criteria for negative feedback systems, 0dB Gain, -1800 phase shift Gain Margin (-1800 phase shift) = 0dB – (-10dB) = 10 dB Phase Margin(0dB gain) = -1000 – (-1800) = 800 19 Bullock Engineering Research Copyright 2008
    • Cascaded PN-code Matched Filters for Increased Process Gain and Margin 11 1 11 1 1 11 1 -1 -1 -1 -1-1 -1 1 delay 1 delay 1 delay 1 delay 1 -1 1 1 1 -1 1 1 PN- Code 1 1 1 1 44 4 sum 1 delay 1 delay 1 delay 1 delay Additional PN- Code 4 -4 4 4 (Or retrieve data direct) 1 -1 1 1 -4 4 4 4 4 sum 16 4 4 4 4 Position of Pulse output provides data information 20 Bullock Engineering Research Copyright 2008
    • Comparison between Absolute and Differential PPM Data Lost Reference Pulse TOA Pulse 1 TOA Pulse 3 TOA Pulse 2 .. Dead Time Dead Time Dead Time t0 t1 t2 t3 t0 t1 t2 t3 t4 t5 t6 t7 t0 t1 t2 t3 t4 t5 t6 t7 Time Slots of PPM No Pulse detected Time Slots of PPM in Time Slots Data output 000 Data output 011 No Data Output Absolute PPM Data Lost Data Lost TOA Pulse 2 Reference Pulse TOA Pulse 1 TOA Pulse 3 No Dead Time Dead Time Dead Time No Time Slots of PPM t0 t1 t3 t4 t5 t6 t7 t0 t1 t3 t4 t5 t6 t7 t2 t2 t0 t1 t2 t3 No Pulse detected Received Pulse ok but Time Slots of PPM in Time Slots No time reference Data output 000 No Data Output No Data output But Provides reference For next pulse Differential PPM 21 Bullock Engineering Research Copyright 2008
    • Coherent vs Differential Bit Errors Bit error Sent digital data 11 0 1 011 0 111 000 1 0 1 0 Received digital data 11 0 1 011 1 111 000 1 0 1 0 One Received data error Coherent System Bit error Sent digital data 10 1 1 1 10 1 100 100 1 1 1 1 Received digital data 10 1 1 1 10 0 000 100 1 1 1 1 Two Received data errors Differential System 22 Bullock Engineering Research Copyright 2008
    • Sliding Correlator 23 Bullock Engineering Research Copyright 2008
    • Intersymbol Interference (ISI) One received symbol interfering with adjacent received symbols • Caused by Dispersion • – Pulse stream/pulse consists of many frequencies – Fourier Series/Transform – Frequencies propagate at different delays – non-constant group delay ISI Dispersion Non- Linear Receiver Non-Constant Group Delay Vh = highest Vpeak center of the eye. Vl = lowest Vpeak center of the eye. ISI = -20log(Vh/Vl) 24 Bullock Engineering Research Copyright 2008
    • CDF Equation For Gaussian Distribution Probability Density Function for Gaussian Distribution Cumulative Distribution Function for Gaussian Distribution x = -1  x = +1  1 or 100% Fx (x) CDF Probability of Occurrence .159 95.4%. .023 x=-2 x = +2  fx (x) for x = -1  fx (x) for x = -2  Value x f Fx(x) = 1/2[1+erf(x/( 2 ))], mean = 0 • Fx(x) = 1/2[1+erf(-2/( 2 ))] • =1/2[1+erf(- 2 )] – – erf(-x) = -erf(x), -erf(1.414) = -.954 – Fx(x) = 1/2[1- .954] = .023 – Probability +/- 2 = 2*.023 =.0456 – Probability inside curve = 1-.0456 = .954 = 95.4%. 25 Bullock Engineering Research Copyright 2008
    • Probability of Error Curves 1.00E+00 1.00E-01 1.00E-02 Coherent BPSK 1.00E-03 Coherent QPSK Pe DPSK Coherent FSK 1.00E-04 NonCoherent FSK 1.00E-05 1.00E-06 1.00E-07 10 11 12 13 14 15 1 2 3 4 5 6 7 8 9 Eb/No (dB) 26 Bullock Engineering Research Copyright 2008
    • Probability of Detection and False Alarms Curves Cumulative distribution function determines probabilities of one sided • noise and S+N gaussian probability density functions – CDF from the right – sum probabilities from the right. 0 1.00E+00 0.00102259 #NAME? #NAME? 1 5 6.99 7.78 0.1 1.20E+00 9.97E-01 1.34E-03 #NAME? #NAME? 1 5 6.99 7.78 0.2 9.89E-01 1.75E-03 #NAME? #NAME? 1 5 6.99 7.78 Threshold Pfa Pd 0.3 1.00E+00 9.76E-01 2.28E-03 #NAME? #NAME? 1 5 6.99 7.78 0.4 9.57E-01 2.94E-03 #NAME? #NAME? 1 5 6.99 7.78 Probability of Occurance 0.5 9.33E-01 3.78E-03 #NAME? #NAME? 1 5 6.99 7.78 0.6 8.00E-01 Noise 9.06E-01 4.83E-03 #NAME? #NAME? 1 5 6.99 7.78 Signal + Noise 5 0.7 8.74E-01 6.14E-03 #NAME? #NAME? 1 6.99 7.78 0.8 6.00E-01 8.38E-01 7.76E-03 #NAME? #NAME? 1 5 6.99 7.78 0.9 8.00E-01 9.76E-03 #NAME? #NAME? 1 5 6.99 7.78 1 4.00E-01 7.59E-01 1.22E-02 #NAME? #NAME? 1 5 6.99 7.78 1.1 7.17E-01 1.52E-02 #NAME? #NAME? 1 5 6.99 7.78 1.2 6.73E-01 1.87E-02 #NAME? #NAME? 1 5 6.99 7.78 1.3 2.00E-01 6.28E-01 2.30E-02 #NAME? #NAME? 1 5 6.99 7.78 1.4 5.83E-01 2.82E-02 #NAME? #NAME? 1 5 6.99 7.78 1.5 0.00E+00 5.38E-01 3.43E-02 #NAME? #NAME? 1 5 6.99 7.78 0 0.6 1.2 1.8 2.4 3 3.6 4.2 4.8 5.4 6 6.6 7.2 7.8 8.4 9 9.6 10.2 10.8 11.4 12 12.6 13.2 13.8 1.6 4.94E-01 4.14E-02 #NAME? #NAME? 1 5 6.99 7.78 1.7 4.51E-01 4.98E-02 #NAME? #NAME? 1 5 6.99 7.78 Energy 27 Bullock Engineering Research Copyright 2008
    • FEC Code Generation n bit code word Block k Information Bits n = Block Length Encoder Maps k information bits into an n-symbol output block Block Codes (Hamming, Cyclic, Reed Solomon Codes) Figure 6.7.2.2a Block Codes (Hamming, Cyclic, RS Codes) XOR Tapped Delay Line Output Symbols Information 1234567 Two times the Input Bits Input Rate 7-bit shift Register switch XOR •Convolutional code, rate ½, constraint length 7 Figure 6.7.2.2b Rate 1/2 Convolutional Encoder 28 Bullock Engineering Research Copyright 2008
    • Example of Generating a Linear Systematic Block Code (7,4) Generator Matrix Message Modulo-2 (1000011) 1 (1000011) (0100110) 0 (0010111) 1 (0010111) (0001101) 0 Systematic Code Word =(1010100) –4 bits of data Identity Matrix Messages Codewords (7,4) –3 parity bits (0000) (0000000) (0001) (0001101) (0010) (0010111) (0011) (0011010) (0100) (0100110) (0101) (0101011) (0110) (0110001) (0111) (0111100) (1000) (1000011) (1001) (1001110) (1010) (1010100) (1011) (1011001) (1100) (1100101) (1101) (1101000) (1110) (1110010) (1111) (1111111) 29 Bullock Engineering Research Copyright 2008
    • Error Correction H-T Error Vector Coset, error vectors e6,e5,e4,e3,e2,e1,e0 * 011 0 e6 e6 1000000 110 e5 e5 0 0100000 111 = e4 e4 e4 0010000 101 e3 0 e3 0001000 100 e2 0 0 0000100 010 0 e1 0 0000010 001 0 0 e0 0000001 e5+e4+e3+e2 = 0 e6+e5+e4+e1 = 0 e6+e4+e3+e0 = 1 0 0 1 3 equations, 7 unknowns (7-3=4), possible solutions = 24 Solve for a solution with the most zeros = all zeros except for e0 = 0000001 e6=e5=e4=e3=e2=e1=0 and e0 = 0000001 satisfies the three above equations with most zeros Correct Code sent = 1010100 Vc = r+e = 1010101+ 0000001 = 1010100 Corrected bit in code word 30 Bullock Engineering Research Copyright 2008
    • Trellis Diagrams   1st merge, need to make a decision  2 possible paths       Constant Mod hi = 1/4    1st merge       Multi-h [1,2/4], [hi] = [1/4,2/4] 31 Bullock Engineering Research Copyright 2008
    • Turbo Codes Turbo Encoder Mux Parallel/Serial PAD Turbo Encoded Output Information Bits Puncturing PAD appends n – k tail bits for all zeros state, x0 Encoder 1 Recursive Systematic Code Generator Interleaver Encoder 2 + Input Z-1 Z-1 Z-1 Z-1 + Turbo Decoder De-Mux Turbo Encoded Decoder 1 Interleaver Decoder 2 De-Interleaver Estimated Serial/Parallel Input Sequence Insertion De-Interleaver 32 Bullock Engineering Research Copyright 2008
    • Diffuse Reflection over a Glistening Surface Receiver R hr Reflected rays Off Glistening Surface Transmitter ht Glistening Surface 33 Bullock Engineering Research Copyright 2008
    • Antenna Diversity 34 Bullock Engineering Research Copyright 2008
    • Quadrature GSO System OMNI Antenna (Jammer only) Jammer Only I PD PD 0 wi int PD LO 90 - I signal out error i Q + Directional Antenna (Signal + Jammer) Jammer Only PD PD 0 wq int PD LO 90 - Q signal out error q + 35 Bullock Engineering Research Copyright 2008
    • Wideband Adaptive Filter 10 dB High Freq Wideband Wideband + Narrowband Signal Only -10 dB Narrowband Signal Estimate -10 dB -10 dB Signal Residual 10 dB 10 dB Synthesizer Narrowband Signal LO BPF BPF 10 dB BPF 30 dB BPF BPF o o 0 -90 4-port 10 dB PD LPF LPF LPF 30 dB 30 dB 15 dB 15 dB 15 dB Update shared weights Digital LPF Q-channel Filter Digital LPF Filter I-channel 15 dB LMS 36 Bullock Engineering Research Copyright 2008
    • GPS Landing Systems D8PSK LPI/Anti-jam Data Link Sends GPS Corrections 37 Relative GPS for moving platforms (Aircraft Carriers) Bullock Engineering Research Kinematic Carrier Phase Tracking KCPT for CATIII landing systems Copyright 2008
    • Need to Provide a Military Communications Network MILCOM 38 Bullock Engineering Research Copyright 2008
    • Interferometer Antenna 1 Phase 1 INTERFEROMETER Baseline Phase 2 Antenna 2 Measures the phase difference between two antennas 39 Bullock Engineering Research Copyright 2008
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