基于16QAM的OFDM仿真Matlab实现.rar

%OFDM.m % This simulation is part of the textbook (Hardback & eBook) “Fundamentals of Communication Systems” % by Janak Sodha. All the theory in this book is supported by simulations via the % app “Communication Systems” available in the Apple and Google Play store. % Further details of the textbook, video lectures and simulations are on Amazon.com and iTunes % Search by author surname. clc clear close echo on T = 2; fc = 1; %% Using fc for the subcarrier frequency M = 16; Eb = 15/6; p = 0.5; A = sqrt((3*Eb*Logtwo(M))/(2*(M - 1))); a(1,1) = -3; a(2,1) = -3; a(3,1) = -3; a(4,1) = -3; a(5,1) = -1; a(6,1) = -1; a(7,1) = -1; a(8,1) = -1; a(9,1) = 3; a(10,1) = 3; a(11,1) = 3; a(12,1) = 3; a(13,1) = 1; a(14,1) = 1; a(15,1) = 1; a(16,1) = 1; b(1,1) = -3; b(2,1) = -1; b(3,1) = 3; b(4,1) = 1; b(5,1) = -3; b(6,1) = -1; b(7,1) = 3; b(8,1) = 1; b(9,1) = -3; b(10,1) = -1; b(11,1) = 3; b(12,1) = 1; b(13,1) = -3; b(14,1) = -1; b(15,1) = 3; b(16,1) = 1; %% To check complex representation of QAM signal is correct %% for any given signal point i = 3; %Select any signal point between 0 to 15 PlotSignal((i+1), A, T, fc, a, b) %% To plot the QAM signal constellation diagram pause close PlotSignalSpace(M, Eb, T, A, fc, a, b) %% Now to extract a[] from X echo off for i = 0 : 15 disp(real(X(i+1, A, a, b))); end echo on %% Now to extract b[] from X echo off for i = 0 : 15 disp(imag(X(i+1, A, a, b))); end echo on %% To check demod function SNR = 100; %Essentially Noiseless echo off for i = 1:1:M Constellation(i).hor = quadl('xhsi', 0,T, [], [], i, A, T, fc, a, b); Constellation(i).ver = quadl('xvsi', 0,T, [], [], i, A, T, fc, a, b); end echo on %Generate two binary digits randomly echo off for bit = 1 : 1: Logtwo(M) symbol(bit,1) = BinarySource(p); end echo on signalpoint = Binary2Dec(symbol) %Given that Matlab cannot handle an array with subscript zero, %we are forced to add 1 to the signal point value, to change the range % from 0 - 15 to 1 - 16. tempsignalpoint = signalpoint + 1; recpoint = AWGN(tempsignalpoint, SNR, Eb, Constellation); recsymbol = Demod(recpoint, Constellation, Eb, M); recpoint = recsymbol - 1 %To recover the signal point %% OFDM Simulation under noiseless channel K = 16; %Try different values [SignalPoints, RecPoints, XX, Xprime, x, Y] = OFDMDCS(K, A, a, b, Constellation, Eb, M, p); %% Signal points transmitted SignalPoints %% Signal points Decoded RecPoints %% XX array XX %% Xprime array Xprime %% x sequence x %% Y points to be demodulated Y %% To plot OFDM baseband signal pause close N = 2*(K + 1); Plotvbaseband(XX, K, T, N, x) %% To plot OFDM bandpass signal pause close fshift = 10; % Note that fshift here is the frequency shift %% of the OFDM baseband signal %% and not the subcarrier frequency. Plotvbandpass(XX, K, T, fshift)