Wireless Communication Systems in MATLAB

Description

In this book shows the theoretical aspects of how a wireless communication system can be translated into simulation models, using elementary matrix operations in Matlab. Most of the simulation models shown in this book, will not use any of the inbuilt communication toolbox functions. This provides an opportunity for a practicing engineer to understand the basic implementation aspects of modeling various building blocks of a wireless system. The book is intended to be used primarily by undergraduate and graduate students in electrical engineering discipline, who wish to learn the basic implementation aspects of a wireless system. Part I Fundamental Concepts Essentials of Signal Processing Generating standard test signals Sinusoidal signals Square wave Rectangular pulse Gaussian pulse Chirp signal Interpreting FFT results - complex DFT, frequency bins and FFTShift Real and complex DFT Fast Fourier Transform (FFT) Interpreting the FFT results FFTShift IFFTShift Some observations on FFTShift and IFFTShift Obtaining magnitude and phase information from FFT Discrete-time domain representation Representing the signal in frequency domain using FFT Reconstructing the time domain signal from the frequency domain samples Plotting frequency response Power spectral density Power and energy of a signal Energy of a signal Power of a signal Classification of signals Computation of power of a signal - simulation and verification Polynomials, convolution and Toeplitz matrices Polynomial functions Representing single variable polynomial functions Multiplication of polynomials and linear convolution Toeplitz matrix and convolution Methods to compute convolution Method 1: Brute-force method Method 2: Using Toeplitz matrix Method 3: Using FFT to compute convolution Miscellaneous methods Analytic signal and its applications Analytic signal and Fourier transform Applications of analytic signal Choosing a filter : FIR or IIR : understanding the design perspective Design specification General considerations in design References Random Variables - Simulating Probabilistic Systems Introduction Plotting the estimated PDF Univariate random variables Uniform random variable Bernoulli random variable Binomial random variable Exponential random variable Poisson process Gaussian random variable Chi-squared random variable Non-central Chi-Squared random variable Chi distributed random variable Rayleigh random variable Ricean random variable Nakagami-m distributed random variable Central limit theorem - a demonstration Generating correlated random variables Generating two sequences of correlated random variables Generating multiple sequences of correlated random variables using Cholesky decomposition Generating correlated Gaussian sequences Spectral factorization method Auto-Regressive (AR) model References Part II Channel Capacity and Coding Theory Channel Capacity Introduction Shannon's noisy channel coding theorem Unconstrained capacity for bandlimited AWGN channel Shannon's limit on spectral efficiency Shannon's limit on power efficiency Generic capacity equation for discrete memoryless channel (DMC) Capacity over binary symmetric channel (BSC) Capacity over binary erasure channel (BEC) Constrained capacity of discrete input continuous output memoryless AWGN channel Ergodic capacity over a fading channel References Linear Block Coding Introduction to error control coding Error control schemes Channel coding – metrics Overview of block codes Error-detection and error-correction capability Decoders for block codes Classification of block codes Theory of linear block codes Optimum soft-decision decoding of linear block codes for AWGN channel Sub-optimal hard-decision decoding of linear block codes for AWGN channel Standard array decoder Syndrome decoding Some classes of linear block codes Repetition codes Hamming codes Maximum-length codes Hadamard codes Performance simulation of soft and hard decision decoding of hamming codes References Part III Digital Modulations Digital Modulators and Demodulators : Complex Baseband Equivalent Models Passband and complex baseband equivalent model Complex baseband representation of modulated signal Complex baseband representation of channel response Modulators for amplitude and phase modulations Pulse Amplitude Modulation (M-PAM) Phase Shift Keying Modulation (M-PSK) Quadrature Amplitude Modulation (M-QAM) Demodulators for amplitude and phase modulations M-PAM detection M-PSK detection M-QAM detection Optimum detector on IQ plane using minimum Euclidean distance M-ary FSK modulation and detection Modulator for M orthogonal signals M-FSK detection References Performance of Digital Modulations over Wireless Channels AWGN channel Signal to noise ratio (SNR) definitions AWGN channel model Theoretical symbol error rates Unified simulation model for performance simulation Fading channels Linear time invariant channel model and FIR filters Simulation model for detection in flat fading channel Rayleigh flat-fading channel Ricean flat-fading channel References Part IV Intersymbol Interference and Equalizers Pulse Shaping, Matched Filtering and Partial Response Signaling Introduction Nyquist criterion for zero ISI Discrete-time model for a system with pulse shaping and matched filtering Rectangular pulse shaping Sinc pulse shaping Raised-cosine pulse shaping Square-root raised-cosine pulse shaping Eye diagram Implementing a matched filter system with SRRC filtering Plotting the eye diagram Performance simulation Partial response (PR) signaling models Impulse response and frequency response of PR signaling schemes Precoding Implementing a modulo-M precoder Simulation and results References Linear Equalizers Introduction Linear equalizers Symbol-spaced linear equalizer channel model Zero-forcing equalizer Least squares solution Noise enhancement Design and simulation of zero-forcing equalizer Drawbacks of zero-forcing equalizer Minimum mean square error (MMSE) equalizer Alternative solution Design and simulation of MMSE equalizer Equalizer delay optimization BPSK modulation with zero-forcing and MMSE equalizers Adaptive equalizer: Least mean square (LMS) algorithm References Receiver Impairments and Compensation Introduction DC offsets and compensation IQ imbalance model IQ imbalance estimation and compensation Blind estimation and compensation Pilot based estimation and compensation Visualizing the effect of receiver impairments Performance of M-QAM modulation with receiver impairments References Part V Wireless Channel Models Large-scale Propagation Models Introduction Friis free space propagation model Log distance path loss model Two ray ground reflection model Modeling diffraction loss Single knife-edge diffraction model Fresnel zones Hata Okumura model for outdoor propagation References Small-scale Models for Multipath Effects Introduction Statistical characteristics of multipath channels Mutipath channel models Scattering function Power delay profile Doppler power spectrum Classification of small-scale fading Rayleigh and Rice processes Probability density function of amplitude Probability density function of frequency Modeling frequency flat channel Modeling frequency selective channel Method of equal distances (MED) to model specified power delay profiles Simulating a frequency selective channel using TDL model References Multiple Antenna Systems - Spatial Diversity Introduction Diversity techniques Single input single output (SISO) channel model Multiple antenna systems channel model Diversity and spatial multiplexing Classification with respect to antenna configuration Two flavors of multiple antenna systems Spatial diversity Spatial multiplexing Receive diversity Received signal model Maximum ratio combining (MRC) Equal gain combining (EGC) Selection combining (SC) Performance simulation Array gain and diversity gain Transmit diversity Transmit beamforming with CSIT Alamouti code for CSIT unknown References Part VI Multiuser and Multitone Communication Systems Spread Spectrum Techniques Introduction Code sequences Sequence correlations Maximum-length sequences (m-sequences) Gold codes Direct sequence spread spectrum Simulation of DSSS system Performance of direct sequence spread spectrum over AWGN channel Performance of direct sequence spread spectrum in the presence of a Jammer Frequency hopping spread spectrum Simulation model Binary frequency shift keying (BFSK) Allocation of frequency channels Frequency hopping generator Fast and slow frequency hopping Simulation code for BFSK-FHSS References Orthogonal Frequency Division Multiplexing (OFDM) Introduction Understanding the role of cyclic prefix in a CP-OFDM system Circular convolution and designing a simple frequency domain equalizer Demonstrating the role of cyclic prefix Verifying DFT property Discrete-time implementation of baseband CP-OFDM Performance of MPSK-CP-OFDM and MQAM-CP-OFDM on AWGN channel Performance of MPSK-CP-OFDM and MQAM-CP-OFDM on frequency selective Rayleigh channel References Index