1 function passband(rolloff, M, numSymbs)
2 %% Set defaults for inputs
13 %% https://www.mathworks.com/help/comm/examples/passband-modulation-with-adjacent-channel-interference.html
14 Rsym = 2.5e10; % symbol rate (sym/sec)
16 span = 6; % filter span
17 sps = 4; % samples per symbol
19 fs = Rsym * sps; % sampling freq (Hz)
21 t = (0 : 1 / fs : numSymbs / Rsym + (1.5 * span * sps - 1) / fs)';
25 EbN0 = 10 .^ (EbN0_db ./ 10);
31 EsN0 = EbN0 .* log2(M);
32 EsN0_db = 10 .* log10(EsN0);
34 plotlen = length(EbN0);
36 ber = zeros(1, plotlen);
39 data = randi([0 M - 1], numSymbs, 1);
40 modData = pskmod(data, M, 0, 'gray');
42 xBaseband = txFilter(modData, rolloff, span, sps);
44 fc = 1e12; % Carrier freq (Hz)
45 carrier = sqrt(2) * exp(j * 2 * pi * fc * t);
47 xPassband = xBaseband .* carrier(1:length(xBaseband));
50 snr = EbN0_db(i) + 10 * log10(log2(M)) - 10 * log10(sps);
51 noiseEnergy = 10 ^ (-snr / 10);
53 yPassband = awgn(xPassband, snr, 'measured');
54 yLO = yPassband .* conj(carrier(1:length(yPassband)));
55 rBaseband = rxFilter(yLO, rolloff, span, sps);
57 rSampled = rBaseband(sps*span/2+1:sps:(numSymbs + span/2) * sps);
59 demodData = pskdemod(rSampled, M, 0, 'gray');
60 [bitErrors, ber(i)] = biterr(data, demodData);
66 %% Plot simulated results
67 semilogy(EbN0_db, ber, 'r', 'LineWidth', 2);
70 theoreticalPSK(EbN0_db, M, 'b', 'LineWidth', 1);
71 legend('Simulated RRC', 'Discrete');
73 title(strcat(num2str(M), '-PSK RRC with Gray code'));
75 xlabel('$E_b/N_0$ (dB)');