s.wavelengthplan = calcWavelengthPlan(16, 400e9, 1310); N = numel(s.wavelengthplan); link_length = 10; s.pmd = 0.1;%0.1; s.gamma = 0.0023; s.M = 4; fsym = 112e9; fdac = 2*fsym; fadc = 120000000000; s.random_key = 1; % Laser / s.Modulator vbias_rel = 0.5; u_pi = 4.6; vbias = -vbias_rel*u_pi; laser_linewidth = 0e6; % DB Stuff duob_mode = db_mode.no_db; rcalpha = 0.05; Pform = Pulseformer("fsym",fsym,"fdac",4*fsym,"pulse","rc","pulselength",16,"alpha",rcalpha); s.chirpalpha = 0; s.p_launch = 3; s.p = "co"; switch s.p case "co" pol_rot = 100.*ones(1,N); d_local = 0; case "pair" pol_rot = repmat([100,100,0,0],1,N/4); d_local = 0; case "alt" pol_rot = repmat([100,0,100,0],1,N/4); d_local = 0; case "seg" pol_rot = 100.*ones(1,N); d_local = 3; otherwise error('Unknown fwm_mitigation_technique: %s', string(s.p)); end f_plan = physconst('lightspeed')./(s.wavelengthplan.*1e-9); margin = 25e12; % some THz left and right f_span = (max(f_plan)+margin)-(min(f_plan)-margin); f_nyq = f_span/2; kover = 4; upsample_required = f_nyq./(fdac*kover/2); upsample_pow = 2^nextpow2(upsample_required); s.f_opt = fdac*kover*upsample_pow; s.f_opt_nyq = s.f_opt/2; s.rop = -10:1:0; profile on %% ---------- TX per channel ---------- for l = 1:N [Digi_sig,Symbols{l},Tx_bits{l}] = PAMsource( ... "fsym",fsym,"M",s.M,"order",17,"useprbs",0, ... "fs_out",fdac, ... "applyclipping",0,"clipfactor",1.5, ... "applypulseform",1,"pulseformer",Pform, ... "randkey",s.random_key+l, ... "mrds_code",0,"mrds_blocklength",512,"duobinary_mode",duob_mode ... ).process(); Lp_awg = Filter('filtdegree',3,"f_cutoff",56e9,"fs",fdac*kover, ... "filterType",filtertypes.gaussian,"active",true); El_sig = AWG("fdac",fdac,"f_cutoff",fsym,"lpf_active",1,"kover",kover, ... "bit_resolution",6,"upsampling_method","samplehold","precomp_sinc_rolloff",0, ... "H_lpf",Lp_awg,"dac_max",0.6,"dac_min",-0.6).process(Digi_sig); % Digi_sig not needed after AWG clear Digi_sig % Electrical Driver Amplifier El_sig = El_sig.normalize("mode","oneone"); scaling = 0.6*(u_pi/2-abs(vbias-u_pi/2)); El_sig = El_sig .* scaling; % E/O Conversion Eml_out = EML("mode",eml_mode.im_cosinus,"power",3,"fsimu",El_sig.fs, ... "lambda",s.wavelengthplan(l),"bias",vbias,"u_pi",u_pi, ... "linewidth",laser_linewidth,"randomkey",s.random_key+l,"alpha",s.chirpalpha).process(El_sig); % El_sig not needed after EML clear El_sig signal_cell{l} = Polarization_Controller("mode","rot_power","desired_power",pol_rot(l)).process(Eml_out); % Eml_out not needed after pol controller clear Eml_out Lp_awg end disp('Signal generated for all channels.'); %% ---------- WDM mux + launch ---------- Opt_sig_wdm = Optical_Multiplex("fs_in",fdac*kover,"fs_out",upsample_pow*fdac*kover, ... "lambda_center",1310,"random_key",0,"filtype",1,"B",120e9).process(signal_cell); Opt_sig_wdm.spectrum(); Opt_sig_wdm = Amplifier("amp_mode","ideal_no_noise","gain_mode","output_power", ... "amplification_db",s.p_launch+10*log10(N)).process(Opt_sig_wdm); Opt_sig_wdm_fib = Opt_sig_wdm; segment_length = 1; nSegments = link_length/segment_length; if abs(nSegments - round(nSegments)) > 1e-12 error('fiber_length_km=%g must be an integer multiple of segment_length=%g km.', link_length, segment_length); end nSegments = round(nSegments); zdw = 1310; randomize_D = true; % Guard for 0 km: avoid calling getDispersionVector(0,...) if it doesn't support it if nSegments > 0 Dvec = getDispersionVector(nSegments, d_local, zdw, randomize_D, s.random_key); else Dvec = []; end for seg = 1:nSegments fprintf('Segment %d/%d \n',seg, nSegments); Opt_sig_wdm_fib = DP_Fiber("L",segment_length,"D",Dvec(seg),"Dpmd",s.pmd,"Ds",0.07, ... "beat_len",10,"corr_len",100,"dz",1,"manakov",0, ... "gamma",s.gamma,"lambda",zdw,"n_waveplates",10,"SS_dphimax",0.01, ... "SS_dzmax",50,"SS_dzmin",10,"X_alpha",0.3,"X_beta",0,"rng",1,"useGPU",true,"useSingle",1).process(Opt_sig_wdm_fib); end profile off profile viewer Opt_sig_wdm_fib.spectrum(); %% ========== BER Evaluation ========== fprintf('\n========== BER Evaluation ==========\n'); fprintf('Processing signals through receiver chain...\n'); % Receiver parameters len_tr = 4096; % Training length mu_dc = 0.005; mu_ffe = [0.0001 0.0008 0.001]; mu_dfe = 0.0004; % Helper function to process through receiver and get BER function ber = process_receiver(Opt_sig_fib, l, Symbols, Tx_bits, ... fdac, kover, upsample_pow, fsym, fadc, rop, s, len_tr, mu_dc, mu_ffe, mu_dfe, duob_mode) % Demux single channel Opt_sig_demux = Optical_Demultiplex("attenuation",0,"B",200e9,"filtype",1, ... "fs_out",fdac*kover,"fs_in",fdac*kover*upsample_pow,"lambda_center",1310).process(Opt_sig_fib); % ROP amplifier Opt_sig_rx = Amplifier("amp_mode","ideal_no_noise","gain_mode","output_power", ... "amplification_db",rop).process(Opt_sig_demux{l}); % Photodiode PD_sig = Photodiode("fsimu",fdac*kover,"dark_current",2e-08,"responsivity",1,"temperature",20, ... "nep",1.8e-11,"randomkey",s.random_key+l).process(Opt_sig_rx); % Low-pass filter rx_bwl = 100e9; PD_sig = Filter('filtdegree',4,"f_cutoff",rx_bwl,"fs",fdac*kover, ... "filterType",filtertypes.butterworth,"active",true).process(PD_sig); % Scope Lp_scpe = Filter('filtdegree',4,"f_cutoff",80e9,"fs",fadc,"filterType",filtertypes.butterworth,"active",true); Scpe_sig = Scope("fsimu",fdac*kover,"fadc",fadc, ... "delay",0,"fixed_delay",0,"filtertype",filtertypes.butterworth, ... "samplingdelay",0,"rand_samplingdelay",0,"freq_offset",0,"samp_jitter",0, ... "adcresolution",8,"quantbuffer",0.1,'block_dc',1,'lpf_active',0,'H_lpf',Lp_scpe).process(PD_sig); % Resample to 2 sps Scpe_sig_2sps = Scpe_sig.resample("fs_out",2*fsym); % Time sync [~, Scpe_cell, ~, ~] = Scpe_sig_2sps.tsynch("reference", Symbols{l}, "fs_ref", fsym, "debug_plots", 0); Rx_sig = Scpe_cell{1}; Rx_sig = Rx_sig.normalize("mode","rms"); % FFE Equalizer ffe_order = [50, 0, 0]; eq_ffe = EQ("Ne",ffe_order,"Nb",[0,0,0],"training_length",len_tr,"training_loops",5,"dd_loops",5, ... "K",2,"DCmu",mu_dc,"DDmu",[mu_ffe mu_dfe],"DFEmu",0.005,"FFEmu",0,"plotfinal",0,"ideal_dfe",0); eq_ffe = FFE("epochs_tr",5,"epochs_dd",2,"len_tr",2^13,"mu_dd",6.624e-05,"mu_tr",0.058136,"order",50,"sps",2,"decide",0, "adaption",adaption_method.nlms,"dd_mode",1); ffe_results = ffe(eq_ffe,s.M,Rx_sig,Symbols{l},Tx_bits{l}, ... "precode_mode",duob_mode, ... 'showAnalysis',0, ... "postFFE",[], ... "eth_style_symbol_mapping",0); ber = ffe_results.metrics.BER; end % Process each ROP value for selected channels using parfor ber_results = zeros(length(s.rop), N); % Flatten loop for parfor: iterate over all (ROP, channel) combinations num_rop = length(s.rop); rop_vals = s.rop; ber_flat = zeros(num_rop * N, 1); parfor idx = 1:(num_rop * N) % Convert linear index to (ri, l) subscripts ri = ceil(idx / N); l = mod(idx - 1, N) + 1; fprintf('ROP %d dBm, Channel %d/%d\n', rop_vals(ri), l, N); ber_flat(idx) = process_receiver(Opt_sig_wdm_fib, l, Symbols, Tx_bits, ... fdac, kover, upsample_pow, fsym, fadc, rop_vals(ri), s, len_tr, mu_dc, mu_ffe, mu_dfe, duob_mode); end % Reshape back to [num_rop × N] matrix ber_results = reshape(ber_flat, [N, num_rop]).'; %% Display BER Results fprintf('\n========== BER Results ==========\n'); fprintf('ROP [dBm] | '); for l = 1:N fprintf('Ch%d | ', l); end fprintf('\n'); for ri = 1:length(s.rop) fprintf('%8d | ', s.rop(ri)); for l = 1:N fprintf('%.2e | ', ber_results(ri, l)); end fprintf('\n'); end % Plot BER vs ROP figure; semilogy(s.rop, mean(ber_results, 2), '-o', 'LineWidth', 2); hold on; for l = 1:N semilogy(s.rop, ber_results(:, l), '--', 'LineWidth', 1); end hold off; xlabel('ROP [dBm]'); ylabel('BER'); title('BER vs Received Optical Power (GPU Single Precision)'); legend(['Mean', arrayfun(@(x) sprintf('Ch%d', x), 1:N, 'UniformOutput', false)]); grid on; fprintf('\n========== Test Complete ==========\n');