Working Kerr effect; PDM; speedups; removed unused files

[4yp.git] / kerr1Signal.m

diff --git a/kerr1Signal.m b/kerr1Signal.m
deleted file mode 100644 (file)
index f4ea292..0000000
--- a/kerr1Signal.m
+++ /dev/null
@@ -1,110 +0,0 @@
-numSymbs = 5e5;
-M = 4;
-
-Rsym = 2.5e10; % symbol rate (sym/sec)
-Tsym = 1 / Rsym; % symbol period (sec)
-
-rolloff = 0.25;
-span = 6; % filter span
-sps = 2; % samples per symbol
-
-fs = Rsym * sps; % sampling freq (Hz)
-Tsamp = 1 / fs;
-
-t = (0 : 1 / fs : numSymbs / Rsym + (1.5 * span * sps - 1) / fs).';
-
-
-%%power_dBm = -3:0.2:4;
-power_dBm = [0];
-power = 10 .^ (power_dBm / 10) * 1e-3; % watts
-
-Es = power * Tsym; % joules
-Eb = Es / log2(M); % joules
-
-N0ref_db = 10; % Eb/N0 at power = 1mW
-%% Fix N0, such that Eb/N0 = N0ref_db at power = 1mW
-N0 = 1e-3 * Tsym / (log2(M) * 10 ^ (N0ref_db / 10)); % joules
-
-
-plotlen = length(power);
-
-ber = zeros(1, plotlen);
-
-data = randi([0 M - 1], numSymbs, 1);
-modData = pskmod(data, M, pi / M, 'gray');
-
-
-%% Chromatic dispersion
-D = 17; % ps / (nm km)
-lambda = 1550; % nm
-z = 600; % km
-
-
-for i = 1:plotlen
-  snr = Es(i) / sps / N0;
-  snr_dB = 10 * log10(snr);
-
-  x = txFilter(modData, rolloff, span, sps);
-  %% Now, sum(abs(x) .^ 2) / length(x) should be 1.
-  %% We can set its power simply by multiplying.
-  x = sqrt(power(i)) * x;
-
-  %% We can now do split-step Fourier.
-  gamma = 1.2; % watt^-1 / km
-  %%stepnum = round(40 * z * gamma); % Nonlinear Fiber optics, App B
-  stepnum = 100;
-  xCD = splitstepfourier(x, D, lambda, z, Tsamp, gamma, stepnum);
-
-  y = awgn(xCD, snr, power(i), 'linear');
-  %%y = xCD;
-
-  r = rxFilter(y, rolloff, span, sps);
-  rCDComp = CDCompensation(r, D, lambda, z, Tsamp);
-  rCDComp = normalizeEnergy(rCDComp, numSymbs*sps, 1);
-
-  rSampled = rCDComp(sps*span/2+1:sps:(numSymbs+span/2)*sps);
-  rNoCompSampled = r(sps*span/2+1:sps:(numSymbs+span/2)*sps);
-
-  %% rotate rNoCompSampled to match original data
-  theta = angle(-sum(rNoCompSampled .^ M)) / M;
-  %% if theta approx +pi/M, wrap to -pi/M
-  if abs(theta - pi / M) / (pi / M) < 0.1
-    theta = -pi / M;
-  end
-  rNoCompSampled = rNoCompSampled .* exp(-j * theta);
-
-
-  %% Not entirely sure why, but after using FFT instead of time-domain
-  %% convolution for simulating CD, we now need to do the same rotation
-  %% for rSampled as well, but this time with a positive rotation.
-  theta = angle(-sum(rSampled .^ M)) / M;
-  if abs(theta + pi / M) / (pi / M) < 0.1
-    theta = +pi / M;
-  end
-  rSampled = rSampled .* exp(-1j * theta);
-
-  %% adaptive filter
-  adaptFilterOut = adaptiveCMA(rSampled);
-
-  demodAdapt = pskdemod(adaptFilterOut, M, pi / M, 'gray');
-  [~, ber(i)] = biterr(data, demodAdapt)
-end
-
-return
-
-
-figure(1);
-clf;
-
-%% Plot simulated results
-semilogy(power_dBm, ber, 'Color', [0, 0.6, 0], 'LineWidth', 2);
-hold on;
-
-title({'CD + Kerr + CD compensation', ...
-       strcat(['$D = 17$ ps/(nm km), $z = ', num2str(z), '$ km'])});
-grid on;
-%%xlabel('$E_b/N_0$ (dB)');
-xlabel('Optical power (dBm)');
-ylabel('BER');
-
-formatFigure;