qpsk.rar_2PSK误码率_2psk_QPSK 误码率_信噪比理论值_误码率 信噪比

%初始化变量 nSamp=8; %采样数/符号 numSymb=100; %符号数 M=4; SNR=14; seed=[12345 54321]; rand('state',seed(1)); randn('state',seed(2)); numPlot = 10; rand('state', seed(1)); msg_orig = randsrc(numSymb, 1, 0:M-1); figure(1); stem(0:numPlot-1, msg_orig(1:numPlot), 'bx'); xlabel('Time'); ylabel('Amplitude'); grayencod = bitxor(0:M-1, floor((0:M-1)/2)); msg_gr_orig = grayencod(msg_orig+1); msg_tx = modulate(modem.pskmod(M), msg_gr_orig); msg_tx = rectpulse(msg_tx,nSamp); h1 = scatterplot(msg_tx); randn('state', seed(2)); msg_rx = awgn(msg_tx, SNR, 'measured', [], 'dB'); h2 = scatterplot(msg_rx); close(h1(ishandle(h1)), h2(ishandle(h2))); msg_rx_down = intdump(msg_rx,nSamp); msg_gr_demod = demodulate(modem.pskdemod(M), msg_rx_down); [dummy graydecod] = sort(grayencod); graydecod = graydecod - 1; msg_demod = graydecod(msg_gr_demod+1)'; figure(2) stem(0:numPlot-1, msg_orig(1:numPlot), 'bx'); hold on; stem(0:numPlot-1, msg_demod(1:numPlot), 'ro'); hold off; axis([ 0 numPlot -0.2 3.2]); xlabel('Time'); ylabel('Amplitude'); [errorBit ratioBit] = biterr(msg_orig, msg_demod, log2(M)); [errorSym ratioSym] = symerr(msg_orig, msg_demod); figure(3) simbasebandex(0:5);