| 1 | numSymbs = 10000; |
| 2 | M = 4; |
| 3 | |
| 4 | Rsym = 2.5e10; % symbol rate (sym/sec) |
| 5 | rolloff = 0.5; |
| 6 | span = 6; % filter span |
| 7 | sps = 8; % samples per symbol |
| 8 | |
| 9 | fs = Rsym * sps; % sampling freq (Hz) |
| 10 | Tsamp = 1 / fs; |
| 11 | |
| 12 | t = (0 : 1 / fs : numSymbs / Rsym + (1.5 * span * sps - 1) / fs).'; |
| 13 | |
| 14 | |
| 15 | EbN0_db = 8; |
| 16 | EbN0 = 10 .^ (EbN0_db ./ 10); |
| 17 | |
| 18 | Es = 1; |
| 19 | Eb = Es / log2(M); |
| 20 | N0 = Eb ./ EbN0; |
| 21 | |
| 22 | EsN0 = EbN0 .* log2(M); |
| 23 | EsN0_db = 10 .* log10(EsN0); |
| 24 | |
| 25 | |
| 26 | data = randi([0 M - 1], numSymbs, 1); |
| 27 | pskSym = pskmod(data, M, pi/M, 'gray'); |
| 28 | dpskSym = dpskmod(data, M, pi/M, 'gray'); |
| 29 | |
| 30 | xPSK = txFilter(pskSym, rolloff, span, sps); |
| 31 | xDPSK = txFilter(dpskSym, rolloff, span, sps); |
| 32 | |
| 33 | linewidthTx = 0; % Hz |
| 34 | linewidthLO = 10e6; % Hz |
| 35 | |
| 36 | [xPSKpn, pTxLoPSK] = phaseNoise(xPSK, linewidthTx, linewidthLO, Tsamp); |
| 37 | [xDPSKpn, pTxLoDPSK] = phaseNoise(xDPSK, linewidthTx, linewidthLO, Tsamp); |
| 38 | |
| 39 | |
| 40 | snr = EbN0_db + 10 * log10(log2(M)) - 10 * log10(sps); |
| 41 | |
| 42 | yPSK = awgn(xPSKpn, snr, 'measured'); |
| 43 | yDPSK = xDPSKpn; |
| 44 | |
| 45 | rPSK = rxFilter(yPSK, rolloff, span, sps); |
| 46 | rDPSK = rxFilter(yDPSK, rolloff, span, sps); |
| 47 | |
| 48 | sps = 2; |
| 49 | Tsamp = Tsamp * 4; |
| 50 | |
| 51 | rPSKSa = rPSK(1:2:end); |
| 52 | rDPSKSa = rDPSK(1:2:end); |
| 53 | |
| 54 | [rPSKSaPhEq, phiestsPSK] = phaseNoiseCorr(rPSKSa, M, pi/M, 80); |
| 55 | |
| 56 | demodPSK = pskdemod(rPSKSaPhEq, M, pi/M, 'gray'); |
| 57 | demodDPSK = dpskdemod(rDPSKSa, M, pi/M, 'gray'); |
| 58 | |
| 59 | |
| 60 | [bitErrors, ber] = biterr(data, demodPSK.') |
| 61 | |
| 62 | |
| 63 | figure(2); |
| 64 | plot(t(1:80000), repelem(-phiestsPSK, 8)); |
| 65 | hold on; |
| 66 | plot(t(1:80000), pTxLoPSK(1:80000)); |
| 67 | legend('estimate', 'actual'); |
| 68 | title('Phase noise estimation'); |
| 69 | hold off; |
| 70 | return |
| 71 | figure(3); |
| 72 | plot(t(1:length(x)), real(normalizeEnergy(x, numSymbs*sps, 1))); |
| 73 | hold on; |
| 74 | %%plot(t, real(rPhaseEq), 'r'); |
| 75 | sampledTimes = t(sps*span/2+1:sps:(numSymbs+span/2)*sps); |
| 76 | %%plot(sampledTimes, real(rSampled), 'x'); |
| 77 | plot(sampledTimes, real(normalizeEnergy(rSaPhEq, numSymbs, 1)), 'x'); |
| 78 | legend('original signal', 'corrected received signal'); |
| 79 | title('Phase noise correction, linewidth 1 MHz, $E_b/N_0=8$ dB'); |
| 80 | ylabel('Real part of signals'); |
| 81 | axis([t(1) t(300) -Inf +Inf]); |
| 82 | hold off; |
| 83 | formatFigure; |