Dies und Das (MPI revisit)
This commit is contained in:
Silas Oettinghaus
146
projects/Diss/investigate_channel_memory.m
Normal file
146
projects/Diss/investigate_channel_memory.m
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@@ -0,0 +1,146 @@
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% Minimal IMDD model for investigating FFE noise enhancement.
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% Parameters mirror the current IMDD_base_system/imdd_it.m,
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% IMDD_base_system/imdd_model.m, and the FFE branch in dsp_scope_signal.m.
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clearvars;
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close all;
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%% Sweep parameters from imdd_it.m
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fsym_values = 172e9;%(152:16:200).*1e9;
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precomp = 0;
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laser_wavelength = 1310;
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M = 4;
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link_length = 2;
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channel_alpha = 0.5;
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duob_mode = db_mode.db_precoded;
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decoding_mode = db_decoder.sequencedetection;
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channel_mode = channel_model.physical;
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channel_snr_dB = 20;
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rop = 0;
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%% Inner model parameters from imdd_model.m
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bitrate = [];
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apply_pulsef = 0;
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fdac = 256e9;
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fadc = 256e9;
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random_key = 1;
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rcalpha = 0.05;
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kover = 16;
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vbias_rel = 0.5;
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u_pi = 3;
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vbias = -vbias_rel*u_pi;
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laser_linewidth = 0;
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eml_alpha = 0;
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len_tr = 4096*2;
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pf_ncoeffs = 1;
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mu_dc = 0.005;
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nRates = numel(fsym_values);
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eq_names = ["FFE","VNLE"];
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nEqs = numel(eq_names);
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emptyResult = struct("fsym",[],"ROP",[],"equalizer",[],"BER",[],"SNR",[],"numBitErr",[], ...
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"eq_noise",[],"eq_signal_sd",[],"eq",[],"Rx_sig",[],"Tx_sig",[],"Tx_symbols",[]);
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results = repmat(emptyResult,nRates,nEqs);
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cols = flip(cbrewer2('RdYlBu',nRates+4));
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midIdx = floor(size(cols,1)/2) + (-1:2);
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cols(midIdx,:) = [];
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for i = 1:numel(fsym_values)
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fsym = fsym_values(i);
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fprintf("Running %.0f GBd (%d/%d)\n", fsym*1e-9, i, numel(fsym_values));
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if isempty(bitrate)
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bitrateCurrent = fsym * log2(M);
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end
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Pform = Pulseformer("fsym",fsym,"fdac",4*fsym,"pulse","rc","pulselength",18,"alpha",rcalpha);
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[Digi_sig, Symbols, Bits] = PAMsource( ...
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"fsym",fsym,"M",M,"order",18,"useprbs",0, ...
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"fs_out",fdac, ...
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"applyclipping",0,"clipfactor",1.5, ...
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"applypulseform",apply_pulsef,"pulseformer",Pform, ...
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"randkey",random_key, ...
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"duobinary_mode",duob_mode, ...
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"mrds_code",0,"mrds_blocklength",512).process();
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rateResults = repmat(emptyResult,nEqs);
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Tx_sig = Digi_sig;
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El_sig = M8199B("kover",kover).process(Digi_sig);
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tx_bwl = 85e9;
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El_sig = Filter("filtdegree",4,"f_cutoff",tx_bwl,"fs",fdac*kover, ...
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"filterType",filtertypes.bessel_inp,"active",true).process(El_sig);
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El_sig = El_sig.normalize("mode","oneone");
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scaling = 0.7*(u_pi/2-abs(vbias-u_pi/2));
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El_sig = El_sig .* scaling;
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Opt_sig = EML("mode",eml_mode.im_cosinus,"power",3,"fsimu",El_sig.fs, ...
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"lambda",laser_wavelength,"bias",vbias,"u_pi",u_pi, ...
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"linewidth",laser_linewidth,"randomkey",random_key+1, ...
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"alpha",eml_alpha).process(El_sig);
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Opt_sig = Fiber("fsimu",Opt_sig.fs,"fiber_length",link_length, ...
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"alpha",0.3,"D",0,"lambda0",1310,"gamma",0,"Dslope",0.07).process(Opt_sig);
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Rx_sig = Amplifier("amp_mode","ideal_no_noise","gain_mode","output_power", ...
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"amplification_db",rop).process(Opt_sig);
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Rx_sig = Photodiode("fsimu",fdac*kover,"dark_current",2e-08, ...
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"responsivity",0.6,"temperature",20,"nep",1.8e-11).process(Rx_sig);
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rx_bwl = 90e9;
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Rx_sig = Filter("filtdegree",4,"f_cutoff",rx_bwl,"fs",fdac*kover, ...
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"filterType",filtertypes.butterworth,"active",true).process(Rx_sig);
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Lp_scpe = Filter("filtdegree",4,"f_cutoff",110e9,"fs",fadc, ...
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"filterType",filtertypes.butterworth,"active",true);
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Rx_sig = Scope("fsimu",fdac*kover,"fadc",fadc, ...
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"delay",0,"fixed_delay",0,"filtertype",filtertypes.butterworth, ...
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"samplingdelay",0,"rand_samplingdelay",0,"freq_offset",0, ...
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"samp_jitter",0,"adcresolution",8,"quantbuffer",0.1, ...
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"block_dc",1,"lpf_active",1,"H_lpf",Lp_scpe).process(Rx_sig);
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txPulseformer = [];
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if apply_pulsef
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txPulseformer = Pform;
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end
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Scpe_sig = preprocessSignal(Rx_sig, Symbols, fsym, ...
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"mode","auto", ...
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"tx_pulseformer",txPulseformer, ...
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"debug_plots",0);
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Scpe_sig.signal = Scpe_sig.signal(1:2*Symbols.length);
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Scpe_sig.signal = real(Scpe_sig.signal);
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%%
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% -------------------- VNLE + MLSE --------------------
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pf_ncoeffs = 1;
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ffe_order3 = [50, 0, 0];
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eq_ = FFE("epochs_tr",5,"epochs_dd",5,"len_tr",len_tr, ...
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"mu_dd",1e-3,"mu_tr",0.4,"order",50, ...
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"sps",2,"decide",0,"optmize_mus",0,"dd_mode",1, ...
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"adaption_technique","nlms","mu_dc",1e-3);
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pf_ = Postfilter("ncoeff",pf_ncoeffs,"useBurg",1);
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mlse_ = MLSE("duobinary_output",0,'M',M,'trellis_states',PAMmapper(M,0).levels);
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[vnle_results, mlse_results] = vnle_postfilter_mlse(eq_, pf_, mlse_, M, Scpe_sig, Symbols, Bits, ...
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"precode_mode", duob_mode, 'showAnalysis', 1, "postFFE", [], "eth_style_symbol_mapping", 0);
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end
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241
projects/Diss/simulation_nonlin_dsp.m
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241
projects/Diss/simulation_nonlin_dsp.m
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@@ -0,0 +1,241 @@
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%%% Run parameters
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% TX
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M = 4;
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m = floor(log2(M)*10)/10;
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fsym = 160e9;
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apply_pulsef = 0;
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fdac = 256e9;
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fadc = 256e9;
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random_key = 1;
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rcalpha = 0.05;
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kover = 16;
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vbias_rel = 0.5;
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u_pi = 3.2;
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vbias = -vbias_rel*u_pi;
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laser_wavelength = 1310;
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laser_linewidth = 0;
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eml_alpha = 0;
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% Channel
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link_length = 0;
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vnle_order1 = 50;
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vnle_order2 = 0;
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vnle_order3 = 0;
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vnle_order=[vnle_order1,vnle_order2,vnle_order3];
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dfe_order = [0 0 0];
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alpha = 0;
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len_tr = 4096*2;
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mu_ffe1 = 0.0001;
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mu_ffe2 = 0.0008;
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mu_ffe3 = 0.001;
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mu_dc = 0.005;
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% mu_dc = 0;
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mu_ffe = [mu_ffe1 mu_ffe3 mu_ffe3];
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mu_dfe = 0.0004;
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dfe_ = sum(dfe_order)>0;
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duob_mode = db_mode.no_db;
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cols = linspecer(6);
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rop = -6;
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bwl = 0.5:0.1:1.5;
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nonlin_mod = 0.5:0.025:0.7;
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fsym = ones(size(nonlin_mod)).*fsym;
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ffe_results = {};
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mlse_results_lin= {};
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vnle_results= {};
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mlse_results_nonlin= {};
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mlse_results_nonlin_states= {};
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g_eye = GifWriter('Name','eye','Parallel',true);
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g_mod = GifWriter('Name','modulator','Parallel',true);
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for r = 1:length(nonlin_mod)
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Pform = Pulseformer("fsym",fsym(r),"fdac",4*fsym(r),"pulse","rc","pulselength",16,"alpha",rcalpha);
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apply_pulsef = 0;
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[Digi_sig,Symbols,Tx_bits] = PAMsource(...
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"fsym",fsym(r),"M",M,"order",18,"useprbs",0,...
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"fs_out",fdac,...
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"applyclipping",0,"clipfactor",1.5,...
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"applypulseform",apply_pulsef,"pulseformer",Pform,...
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"randkey",random_key,...
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"mrds_code",0,"mrds_blocklength",512,"duobinary_mode",duob_mode).process();
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% El_sig = AWG("fdac",fdac,"f_cutoff",fsym(r),"lpf_active",0,"kover",kover,"bit_resolution",12,"upsampling_method","samplehold","precomp_sinc_rolloff",0).process(Digi_sig);
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El_sig = M8199B("kover",kover).process(Digi_sig);
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% AWG("fdac",fdac,"f_cutoff",fsym(r),"lpf_active",0,"kover",kover,"bit_resolution",12,"upsampling_method","samplehold","precomp_sinc_rolloff",0).process(Digi_sig);
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%%%%% Low-pass el. components %%%%%%
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tx_bwl = 85e9;
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El_sig = Filter("filtdegree",4,"f_cutoff",tx_bwl,"fs",fdac*kover, ...
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"filterType",filtertypes.bessel_inp,"active",true).process(El_sig);
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%%%%% Electrical Driver Amplifier %%%%%%
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El_sig = El_sig.normalize("mode","oneone");
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% El_sig = El_sig.setPower(1,"dBm");
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% figure;histogram(El_sig.signal);
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%%%%% MODULATE E/O CONVERSION %%%%%
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% scaling = nonlin_mod(r)*(u_pi/2-abs(vbias-u_pi/2));
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% El_sig = El_sig .* scaling;
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vbias = -nonlin_mod(r)*u_pi;
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[Opt_sig] = EML("mode",eml_mode.im_cosinus,"power",3,"fsimu",El_sig.fs, ...
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"lambda",laser_wavelength,"bias",vbias,"u_pi",u_pi, ...
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"linewidth",laser_linewidth,"randomkey",random_key+1, ...
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"alpha",eml_alpha).process(El_sig);
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if 1
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figure(15);
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hold on
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scatter(El_sig.signal(1:100000)+vbias,(abs(Opt_sig.signal(1:100000)).^2)*1e3,0.1,'.','DisplayName','Modulator TF')
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xlabel('Input in V')
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ylabel('abs(Eopt)2 in mW','Interpreter','latex')
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ylim([0 2]);
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xlim([-3 0]);
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g_mod.addFrame(15, r);
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Opt_sig.eye(fsym(r), M, "fignum", 103837);
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g_eye.addFrame(103837, r);
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end
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%%%%%% Fiber %%%%%%
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Opt_sig = Fiber("fsimu",Opt_sig.fs,"fiber_length",link_length,"alpha",0.3,"D",0,"lambda0",1310,"gamma",0,"Dslope",0.07).process(Opt_sig);
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%%%%%% ROP %%%%%%
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Opt_sig = Amplifier("amp_mode","ideal_no_noise","gain_mode","output_power","amplification_db",rop).process(Opt_sig);
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%%%%%% PD Square Law %%%%%%
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PD_sig = Photodiode("fsimu",fdac*kover,"dark_current",2e-08,"responsivity",0.6,"temperature",20,"nep",1.8e-11).process(Opt_sig);
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%%%%%% Low-pass RX (PD, El. Connectors and Scope %%%%%%
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rx_bwl = 90e9;
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PD_sig = Filter("filtdegree",4,"f_cutoff",rx_bwl,"fs",fdac*kover, ...
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"filterType",filtertypes.butterworth,"active",true).process(PD_sig);
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% %%%%%% Low-pass Scope %%%%%%
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Lp_scpe = Filter("filtdegree",4,"f_cutoff",110e9,"fs",fadc, ...
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"filterType",filtertypes.butterworth,"active",true);
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%%%%%% Scope %%%%%%
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Scpe_sig = Scope("fsimu",fdac*kover,"fadc",fadc,...
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"delay",0,"fixed_delay",0,"filtertype",filtertypes.butterworth,...
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"samplingdelay",0,"rand_samplingdelay",0,"freq_offset",0,"samp_jitter",0,...
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"adcresolution",8,"quantbuffer",0.1,'block_dc',1,'lpf_active',1,'H_lpf',Lp_scpe).process(PD_sig);
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txPulseformer = [];
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if apply_pulsef
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txPulseformer = Pform;
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end
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Rx_sig = preprocessSignal(Scpe_sig, Symbols, fsym(r), ...
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"mode","auto", ...
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"tx_pulseformer",txPulseformer, ...
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"debug_plots",0,"gaussian_cutoff_factor",0.55,"apply_gaussian_filter",true);
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Rx_sig = Rx_sig.normalize("mode","rms");
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Rx_sig.signal = Rx_sig.signal(1:2*Symbols.length);
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Rx_sig.spectrum()
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if 1
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%% FFE
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% ffe_order = [50, 0, 0];
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% 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);
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%
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% ffe_results = ffe(eq_ffe,M,Rx_sig,Symbols,Tx_bits,...
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% "precode_mode",duob_mode,...
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% 'showAnalysis',0,...
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% "postFFE",[],...
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% "eth_style_symbol_mapping",0);
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%
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% ffe_results.metrics.print;
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% ffe_results.config.equalizer_structure = "ffe";
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%
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%% MLSE linear
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pf_ncoeffs = 1;
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ffe_order = [50, 0, 0];
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eq_ = 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",1);
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pf_ = Postfilter("ncoeff",pf_ncoeffs,"useBurg",1);
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mlse_ = MLSE("duobinary_output",0,'M',M,'trellis_states',PAMmapper(M,0).levels,'scale_mode',2,'trellis_exclusion',0,'trellis_state_mode',2,'debug',0);
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[ffe_results{r}, mlse_results_lin{r}] = vnle_postfilter_mlse(eq_, pf_, mlse_, M, Rx_sig, Symbols, Tx_bits, ...
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"precode_mode", duob_mode,...
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'showAnalysis', 0, ...
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"postFFE", [],...
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"eth_style_symbol_mapping", 0);
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mlse_results_lin{r}.metrics.print;
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ffe_results{r}.metrics.print;
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%% MLSE nonlinear pre
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pf_ncoeffs = 1;
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ffe_order = [50, 1, 0];
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eq_ = 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",1);
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pf_ = Postfilter("ncoeff",pf_ncoeffs,"useBurg",1);
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mlse_ = MLSE("duobinary_output",0,'M',M,'trellis_states',PAMmapper(M,0).levels,'scale_mode',2,'trellis_exclusion',0,'trellis_state_mode',2);
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[vnle_results{r}, mlse_results_nonlin{r}] = vnle_postfilter_mlse(eq_, pf_, mlse_, M, Rx_sig, Symbols, Tx_bits, ...
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"precode_mode", duob_mode,...
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'showAnalysis', 0, ...
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"postFFE", [],...
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"eth_style_symbol_mapping", 0);
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mlse_results_nonlin{r}.metrics.print;
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vnle_results{r}.metrics.print;
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%% nonlinear states MLSE linear pre
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pf_ncoeffs = 1;
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ffe_order = [50, 0, 0];
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eq_ = 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",1);
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pf_ = Postfilter("ncoeff",pf_ncoeffs,"useBurg",1);
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mlse_ = MLSE("duobinary_output",0,'M',M,'trellis_states',PAMmapper(M,0).levels,'scale_mode',2,'trellis_exclusion',0,'trellis_state_mode',3);
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[~, mlse_results_nonlin_states{r}] = vnle_postfilter_mlse(eq_, pf_, mlse_, M, Rx_sig, Symbols, Tx_bits, ...
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"precode_mode", duob_mode,...
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'showAnalysis', 0, ...
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"postFFE", [],...
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"eth_style_symbol_mapping", 0);
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mlse_results_nonlin_states{r}.metrics.print;
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end
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end
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g_mod.compile(15);
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g_eye.compile(103837);
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%%
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figure();hold on;
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plot(nonlin_mod,cellfun(@(x) x.metrics.BER, ffe_results),'DisplayName','FFE')
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plot(nonlin_mod,cellfun(@(x) x.metrics.BER, vnle_results),'DisplayName','VNLE')
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plot(nonlin_mod,cellfun(@(x) x.metrics.BER, mlse_results_lin),'DisplayName','FFE+MLSE')
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plot(nonlin_mod,cellfun(@(x) x.metrics.BER, mlse_results_nonlin_states),'DisplayName','FFE+nonlin. states MLSE')
|
||||
plot(nonlin_mod,cellfun(@(x) x.metrics.BER, mlse_results_nonlin),'DisplayName','VNLE+MLSE')
|
||||
xlabel('Nonlinear Driving');
|
||||
ylabel('BER')
|
||||
set(gca,'YScale','log');
|
||||
legend;
|
||||
ylim([1e-4 1e-1]);
|
||||
beautifyBERplot;
|
||||
|
||||
|
||||
Reference in New Issue
Block a user