bpsk.m

再高斯信道和瑞利信道下bpsk误码率的分析

close all;
clear all;
N = 10^6;                              % number of bits
sr_br=1;                               % for bpsk, br=sr. where br: bit rate  sr: symbol rate 
PowS=1;      
Eb_N0_dB = [-3:35];                    % multiple Eb/N0 values
EbN0Lin = 10.^(Eb_N0_dB/10);           % multiple Eb/N0 values in linear
% Transmitter
ip = rand(1,N)>0.5;                    % generating 0,1 with equal probability
s = 2*ip-1;                            % BPSK modulation 0 -> -1; 1 -> 0 
for ii = 1:length(Eb_N0_dB)
       PowN=sr_br*PowS/EbN0Lin(ii);                       % power of noise
    n = sqrt(PowN/2)*[randn(1,N) + j*randn(1,N)];         % white gaussian noise 
    h = 1/sqrt(2)*[randn(1,N) + j*randn(1,N)];            % Rayleigh channel
       y = h.*s + n;                                      % Channel and noise Noise addition
     yHat = y./h;                                         % equalization
     ipHat = real(yHat)>0;                                % receiver - hard decision decoding
     nErr(ii) = size(find([ip- ipHat]),2);                % counting the errors
end
simBer = nErr/N;                                          % simulated ber
theoryBerAWGN = 0.5*erfc(sqrt(EbN0Lin));                  % theoretical ber on AWGN
theoryBerRayleigh = 0.5.*(1-sqrt(EbN0Lin./(EbN0Lin+1)));  % theoretical ber on Rayleighchannel
% plot
figure
semilogy(Eb_N0_dB,theoryBerAWGN,'cd-','LineWidth',2);
hold on
semilogy(Eb_N0_dB,theoryBerRayleigh,'bp-','LineWidth',2);
semilogy(Eb_N0_dB,simBer,'mx-','LineWidth',2);
axis([-3 35 10^-5 0.5])
grid on
legend('AWGN-Theory','Rayleigh-Theory', 'Rayleigh-Simulation');
xlabel('Eb/No, dB');
ylabel('Bit Error Rate');
title('BER for BPSK modulation in Rayleigh channel');