光纤通信ACO-OFDM和其他调制方式光纤通信系统性能对比,AWGN信道模型附Matlab代码.zip

%% Signal values and constellation diagram for ACO-OFDM clear all;close all;clc; N = 16;% no. OFDM subcarriers NCP = 4; % CP length NOFDM = 1; % no.transmitted OFDM symbols EbN0dB_sim = 10; %SNR (dB) QPSK_sig_set = [1+i -1+i 1-i -1-i]; %QPSK signal set h = 0.4.^(0:4); % discrete-time CIR %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% EbN0_sim = 10^(EbN0dB_sim/10); %SNR for simulation N0_sim = (mean(abs(QPSK_sig_set).^2)/2)/EbN0_sim; % N0 b = round(rand(1, 2*NOFDM*(N/4))); % info bits bp1 = b(1:2:length(b)); bp2 = b(2:2:length(b)); m = 2*bp1+bp2+1; %indices for QPSK signal points S = QPSK_sig_set(m); %transmitted signal points S2 = []; s = []; for j = 1:NOFDM tmp = zeros(1, N/2-1); tmp(1:2:N/2-1) = S((j-1)*(N/4)+1:j*(N/4)); S2 = [S2 0 tmp 0 fliplr(conj(tmp))]; tmp = max(sqrt(N)*ifft(S2((j-1)*N+1:j*N)), 0); s = [s tmp(N-NCP+1:N) tmp]; end tmp = conv(h,s); w = sqrt(N0_sim/2)*randn(1, NOFDM*(N+NCP))+ i*sqrt(N0_sim/2)*randn(1, NOFDM*(N+NCP)); %AWGN r = tmp(1:length(s)) + w; % received signal values H = 1/sqrt(N)*fft(h, N); R = []; R2 = []; for j = 1:NOFDM tmp = r((j-1)*(N+NCP)+NCP+1:j*(N+NCP)); tmp = 1/sqrt(N)*fft(tmp)./(sqrt(N)*H); R2 = [R2 tmp]; R = [R tmp(2:2:N/2)]; %s = [s tmp(N-NCP+1:N) tmp]; end b2 = []; % received bits for n = 1:(N/4)*NOFDM if real(R(n)) > 0 & imag(R(n)) > 0; b2 = [b2 0 0]; elseif real(R(n)) <= 0 & imag(R(n)) > 0; b2 = [b2 0 1]; elseif real(R(n)) > 0 & imag(R(n)) <= 0; b2 = [b2 1 0]; else b2 = [b2 1 1]; end end BER = length(find(b ~= b2))/(2*(N/4)*NOFDM); Popt = 10*log(mean(s)*1e3); k = 0:NOFDM*N-1; k2 = 0:NOFDM*(N+NCP)-1; figure(1); % transmit signal subplot(2,2, 1), stem(k, real(S2),'r'); xlabel('k'); ylabel('Re\{S_k\}'); xlim([0 NOFDM*N-1]); subplot(2,2,2), stem(k, imag(S2),'r'); xlabel('k'); ylabel('Im\{S_k\}'); xlim([0 NOFDM*N-1]); subplot(2,2,3), stem(k2, real(s),'b'); xlabel('n'); ylabel('Re\{s_n\}'); xlim([0 NOFDM*(N+NCP)-1]); subplot(2,2,4), stem(k2, imag(s),'b'); xlabel('n'); ylabel('Im\{s_n\}'); xlim([0 NOFDM*(N+NCP)-1]); figure(2); % receive signal subplot(2,2, 1), stem(k2, real(r),'b'); xlabel('n'); ylabel('Re\{r_k\}'); xlim([0 NOFDM*(N+NCP)-1]); subplot(2,2,2), stem(k2, imag(r),'b'); xlabel('n'); ylabel('Im\{r_k\}'); xlim([0 NOFDM*(N+NCP)-1]); subplot(2,2,3), stem(k, real(R2),'r'); xlabel('k'); ylabel('Re\{R_k\}'); xlim([0 NOFDM*N-1]); subplot(2,2,4), stem(k, imag(R2),'r'); xlabel('k'); ylabel('Re\{R_k\}'); xlim([0 NOFDM*N-1]); figure(3); plot(R, '+'); hold on; grid on; plot(QPSK_sig_set,'ro'); xlabel('Re\{R_k}'); ylabel('Im\{R_k}'); axis([-2.5 2.5 -2.5 2.5]); text(-0.4, 2.2, strcat('Eb/N0=', num2str(EbN0dB_sim),'dB'))