function phasenoise_AWGN(rolloff, M, numSymbs) %% Set defaults for inputs if nargin < 3 numSymbs = 1000; end if nargin < 2 M = 2; end if nargin < 1 rolloff = 0.25; end plotted = 0; Rsym = 2.5e10; % symbol rate (sym/sec) span = 6; % filter span sps = 4; % samples per symbol fs = Rsym * sps; % sampling freq (Hz) Tsamp = 1 / fs; t = (0 : 1 / fs : numSymbs / Rsym + (1.5 * span * sps - 1) / fs)'; EbN0_db = 0:0.2:14; EbN0 = 10 .^ (EbN0_db ./ 10); Es = 1; Eb = Es / log2(M); N0 = Eb ./ EbN0; EsN0 = EbN0 .* log2(M); EsN0_db = 10 .* log10(EsN0); plotlen = length(EbN0); ber = zeros(1, plotlen); data = randi([0 M - 1], numSymbs, 1); modData = pskmod(data, M, 0, 'gray'); x = txFilter(modData, rolloff, span, sps); linewidthTx = 0;%1e5; % Hz linewidthLO = 1e6; % Hz %%linewidthTx = Rsym * 1e-4; % Hz %%linewidthLO = Rsym * 1e-3; % Hz totalIterations = 1; for iter = 1:totalIterations [xPN, pTxLO] = phaseNoise(x, linewidthTx, linewidthLO, Tsamp); for i = 1:plotlen snr = EbN0_db(i) + 10 * log10(log2(M)) - 10 * log10(sps); noiseEnergy = 10 ^ (-snr / 10); y = awgn(xPN, snr, 'measured'); r = rxFilter(y, rolloff, span, sps); %% normalize energy %r = normalizeEnergy(r, numSymbs, 1 + noiseEnergy); [rPhaseEq, phiests] = phaseNoiseCorr(r, M, 40 * sps); rSampled = rPhaseEq(sps*span/2+1:sps:(numSymbs + span/2) * sps); demodData = pskdemod(rSampled, M, 0, 'gray')'; %%[bitErrors, ber(i)] = biterr(data, demodData); [zzz, thisBER] = biterr(data, demodData); ber(i) = ber(i) + thisBER / totalIterations; if plotted == 0 && EbN0_db(i) >6 && ber(i) > 1e-1 plotted=1 figure(1234); plot(-phiests); hold on; plot(pTxLO); legend('estimate', 'actual'); hold off; figure(100); %plot(t(1:length(x)), real(x)); %%plot(t, real(x(1:length(t)))); length(t) length(x) hold on %%plot(t(1:length(xPhaseNoise)), real(xPhaseNoise)); plot(t, real(r), 'g') sampledTimes = t(sps*span/2+1:sps:(numSymbs+span/2)*sps); plot(sampledTimes, real(rSampled), 'x') hold off end end end figure(1); clf; %% Plot simulated results semilogy(EbN0_db, ber, 'r', 'LineWidth', 2); hold on; theoreticalPSK(EbN0_db, M, 'b', 'LineWidth', 1); legend({'Simulated phase noise', 'Without phase noise'}, 'Location', 'southwest'); title(strcat(num2str(M), '-PSK with phase noise and correction')); grid on; xlabel('$E_b/N_0$ (dB)'); ylabel('BER'); formatFigure; end