| 1 | numSymbs = 5e5; |
| 2 | M = 4; |
| 3 | rolloff = 0.5; |
| 4 | |
| 5 | Rsym = 2.5e10; % symbol rate (sym/sec) |
| 6 | |
| 7 | span = 6; % filter span |
| 8 | sps = 4; % samples per symbol |
| 9 | |
| 10 | fs = Rsym * sps; % sampling freq (Hz) |
| 11 | Tsamp = 1 / fs; |
| 12 | |
| 13 | t = (0 : 1 / fs : numSymbs / Rsym + (1.5 * span * sps - 1) / fs).'; |
| 14 | |
| 15 | |
| 16 | EbN0_db = 0:0.2:14; |
| 17 | EbN0 = 10 .^ (EbN0_db ./ 10); |
| 18 | |
| 19 | Es = 1; |
| 20 | Eb = Es / log2(M); |
| 21 | N0 = Eb ./ EbN0; |
| 22 | |
| 23 | EsN0 = EbN0 .* log2(M); |
| 24 | EsN0_db = 10 .* log10(EsN0); |
| 25 | |
| 26 | plotlen = length(EbN0); |
| 27 | |
| 28 | ber = zeros(1, plotlen); |
| 29 | |
| 30 | data = randi([0 M - 1], numSymbs, 1); |
| 31 | %%modData = dpskmod(data, M, pi / M, 'gray'); |
| 32 | modData = dpskmod(data, M, 0, 'gray'); |
| 33 | |
| 34 | x = txFilter(modData, rolloff, span, sps); |
| 35 | |
| 36 | linewidthTx = 0; % Hz |
| 37 | %%linewidthLO = 1e6; % Hz |
| 38 | linewidthLO = Rsym * 1e-3; |
| 39 | |
| 40 | |
| 41 | avgSa = 40; |
| 42 | |
| 43 | |
| 44 | [xPN, pTxLO] = phaseNoise(x, linewidthTx, linewidthLO, Tsamp); |
| 45 | |
| 46 | for i = 1:plotlen |
| 47 | snr = EbN0_db(i) + 10 * log10(log2(M)) - 10 * log10(sps); |
| 48 | noiseEnergy = 10 ^ (-snr / 10); |
| 49 | |
| 50 | y = awgn(xPN, snr, 'measured'); |
| 51 | |
| 52 | r = rxFilter(y, rolloff, span, sps); |
| 53 | %% normalize energy |
| 54 | r = normalizeEnergy(r, numSymbs, 1 + noiseEnergy); |
| 55 | |
| 56 | rSampled = r(sps*span/2+1:sps:(numSymbs+span/2)*sps); |
| 57 | [rSaPhEq, phiests] = phaseNoiseCorr(rSampled, M, avgSa); |
| 58 | |
| 59 | adaptiveFilterOut = adaptiveCMA(rSaPhEq.'); |
| 60 | |
| 61 | demodData = dpskdemod(rSaPhEq, M, 0, 'gray').'; |
| 62 | demodAdapt = dpskdemod(adaptiveFilterOut, M, 0, 'gray'); |
| 63 | |
| 64 | [~, ber(i)] = biterr(data, demodData); |
| 65 | |
| 66 | if EbN0_db(i) == 8 |
| 67 | figure(1234); |
| 68 | plot(repelem(-phiests, sps)); |
| 69 | hold on; |
| 70 | plot(pTxLO); |
| 71 | legend('estimate', 'actual'); |
| 72 | hold off; |
| 73 | |
| 74 | figure(1); |
| 75 | scatterplot(rSaPhEq); |
| 76 | title('rSaPhEq'); |
| 77 | end |
| 78 | end |
| 79 | |
| 80 | |
| 81 | figure(1); |
| 82 | clf; |
| 83 | |
| 84 | %% Plot simulated results |
| 85 | semilogy(EbN0_db, ber, 'r', 'LineWidth', 2); |
| 86 | hold on; |
| 87 | |
| 88 | theoreticalPSK(EbN0_db, M, 'b', 'LineWidth', 1); |
| 89 | legend({'Simulated phase noise + correction', 'Theoretical AWGN'}, ... |
| 90 | 'Location', 'southwest'); |
| 91 | |
| 92 | |
| 93 | title({'QPSK with phase nosie and correction', ... |
| 94 | strcat(num2str(numSymbs * log2(M) / 1e3), '~kbit, LO~', ... |
| 95 | num2str(linewidthLO / 1e6), '~MHz, Av~', num2str(avgSa), ... |
| 96 | '~Sa')}); |
| 97 | grid on; |
| 98 | xlabel('$E_b/N_0$ (dB)'); |
| 99 | ylabel('BER'); |
| 100 | |
| 101 | formatFigure; |