% minimal example IM/DD M = 4; fsym = 160e9; apply_pulsef = 1; fdac = 256e9; fadc = 256e9; random_key = 1; rcalpha = 0.05; kover = 16; duob_mode = db_mode.no_db; vbias_rel = 0.5; u_pi = 3; vbias = -vbias_rel*u_pi; laser_wavelength = 1293; laser_linewidth = 0; tx_bw_nyquist = 0.8; % Channel link_length = 1; % RX rop = -9; rx_bw_nyquist = 0.8; vnle_order1 = 50; vnle_order2 = 7; vnle_order3 = 7; vnle_order=[vnle_order1,vnle_order2,vnle_order3]; dfe_order = [0 0 0]; pf_ncoeffs = 1; alpha = 0; len_tr = 4096*2; mu_ffe1 = 0.0001; mu_ffe2 = 0.0008; mu_ffe3 = 0.001; mu_dc = 0.005; % mu_dc = 0; mu_ffe = [mu_ffe1 mu_ffe3 mu_ffe3]; mu_dfe = 0.0004; sf = signalform.prms; Tx_bits = Signalgenerator( ... "form", sf, ... "M", M, ... "order", 16).process(); Symbols = PAMmapper(M,0).map(Tx_bits); Symbols.fs = fsym; Symbols_plain = Symbols; pr = Partialresponse("order", 1,"M",M); Symbols = pr.precode(Symbols); pform = Pulseformer("fsym",fsym,"fdac",4*fsym,"pulse","rc","pulselength",16,"alpha",rcalpha); Digi_sig = pform.process(Symbols); n = 10; Digi_sig = Digi_sig.resample("fs_in",Digi_sig.fs,"fs_out",fdac,"n",n,"beta",5); %%%%% AWG El_sig = M8199A("kover",kover).process(Digi_sig); % El_sig = AWG("fdac",fdac,"f_cutoff",fsym*0.4,"lpf_active",1,"kover",kover,"bit_resolution",12,"upsampling_method","samplehold","precomp_sinc_rolloff",1).process(Digi_sig); tx_bwl = fsym*0.3; El_sig = Filter('filtdegree',4,"f_cutoff",tx_bwl,"fs",fdac*kover,"filterType",filtertypes.butterworth,"active",true).process(El_sig); El_sig.spectrum("displayname",'Digi Spectrum','fignum',1,'normalizeTo0dB',1); xlim([0,130]); ylim([-30,5]); % El_sig = El_sig.setPower(0,"dBm"); %%%%% Electrical Driver Amplifier %%%%%% % El_sig = Amplifier("amp_mode","ideal_no_noise","gain_mode","gain","amplification_db",3).process(El_sig); El_sig = El_sig.normalize("mode","oneone"); scaling = 0.8*(u_pi/2-abs(vbias-u_pi/2)); El_sig = El_sig .* scaling; %%%%% MODULATE E/O CONVERSION %%%%%% [Opt_sig] = EML("mode",eml_mode.im_cosinus,"power",3,"fsimu",El_sig.fs,"lambda",laser_wavelength,"bias",vbias,"u_pi",u_pi,"linewidth",laser_linewidth,"randomkey",random_key+1,"alpha",alpha).process(El_sig); Opt_sig.spectrum("displayname",'Opt Spectrum','fignum',10,'normalizeTo0dB',1); % Opt_sig.eye(fsym,M,"displayname",'eye adter modulator','fignum',2026); 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); %%%%%% ROP %%%%%% Rx_sig = Amplifier("amp_mode","ideal_no_noise","gain_mode","output_power","amplification_db",rop).process(Opt_sig); %%%%%% PD Square Law %%%%%% Rx_sig = Photodiode("fsimu",fdac*kover,"dark_current",2e-08,"responsivity",1,"temperature",20,"nep",1.8e-11).process(Rx_sig); %%%%%% Low-pass RX (PD, El. Connectors and Scope %%%%%% rx_bwl = 80e9; Rx_sig = Filter('filtdegree',4,"f_cutoff",rx_bwl,"fs",fdac*kover,"filterType",filtertypes.butterworth,"active",true).process(Rx_sig); % %%%%%% Low-pass Scope %%%%%% Lp_scpe = Filter('filtdegree',4,"f_cutoff",110e9,"fs",fadc,"filterType",filtertypes.butterworth,"active",true); %%%%%% Scope %%%%%% 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',1,'H_lpf',Lp_scpe).process(Rx_sig); %% % 1) matched filter % pulse is symmetric, hence we can use pulsef firectly as matched filter. % It feels off (bit I think correct) that the fsym is now the output freq.!! % -> output 2 sps to omit timing recovery!? if 0 Pform = Pulseformer("fsym",fsym,"fdac",2*fsym,"pulse","rrc","pulselength",16,"alpha",rcalpha,"matched",1); Scpe_sig = Pform.process(Scpe_sig); end % Scpe_sig.spectrum("displayname",'Signal after matched filter','fignum',1,'normalizeTo0dB',1); % % %% % %%%%%% Sample to 2x fsym %%%%%% Scpe_sig = Scpe_sig.resample("fs_out",2*fsym); Scpe_sig.signal = Scpe_sig.signal(1:2*length(Symbols)); %% %%%%%% Sync Rx signal with reference %%%%%% [Scpe_sig,~] = Scpe_sig.tsynch("reference",Symbols,"fs_ref",fsym,"debug_plots",0); % Scpe_sig.spectrum("displayname",'Opt Spectrum','fignum',11,'normalizeTo0dB',1); % Scpe_sig = Filter('filtdegree',4,"f_cutoff",Symbols.fs.*0.5,"fs",Scpe_sig.fs,"filterType",filtertypes.gaussian,"active",true).process(Scpe_sig); Scpe_sig = Scpe_sig - mean(Scpe_sig.signal); Scpe_sig.signal = Scpe_sig.signal(1:2*length(Symbols)); %% -------------------- MLSE -------------------- mlse_ = MLSE("DIR",[1,1],"duobinary_output",0,"M",M,'trellis_states',PAMmapper(M,0).levels); ffe_order = [50, 2, 2]; 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); %Duobinary Targeting db_ref_sequence = Duobinary().encode(Symbols); [eq_signal, eq_noise] = eq_.process(Scpe_sig,db_ref_sequence); showLevelHistogram(eq_signal,db_ref_sequence) [mlse_sig_sd,LLR,GMI_MLSE] = mlse_.process(eq_signal,Symbols); Rx_bits = PAMmapper(M,0).demap(mlse_sig_sd); Tx_bits_omitprecode = PAMmapper(M,0).demap(Symbols); [bits,errors,ber_wo,errorIndice] = calc_ber(Rx_bits.signal,Tx_bits_omitprecode.signal); fprintf(["BER w/o precode: %.2d \n"],ber_wo); showErrorBurstCount(mlse_sig_sd, Symbols,"displayname",'MLSE DB w/o Precode','fignum',4); % prior to coding %% mlse_sig_sd = pr.encode(mlse_sig_sd); mlse_sig_sd = pr.decode(mlse_sig_sd); Rx_bits = PAMmapper(M,0).demap(mlse_sig_sd); [bits,errors,ber,errorIndice] = calc_ber(Rx_bits.signal,Tx_bits.signal); fprintf(["BER w/ precode: %.2d \n"],ber); showErrorBurstCount(mlse_sig_sd, Symbols_plain,"displayname",'MLSE DB w/ Precode','fignum',5); %% -------------------- FFE -------------------- ffe_order = [50, 0, 0]; eq_ = EQ("Ne",ffe_order,"Nb",[2,0,0], ... "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("epochs_tr",4,"epochs_dd",5,"len_tr",4096,"mu_dd",0.01,"mu_tr",0.01,"order",50,"sps",2,"decide",0, "adaption",adaption_method.nlms,"dd_mode",1); % eq_ = FFE_DFE("epochs_tr",5,"epochs_dd",5,"len_tr",512,"ffe_mu_dd",1e-4,"dfe_mu_dd",5e-4,"ffe_mu_tr",0,"dfe_mu_tr",0,"ffe_order",99,"dfe_order",99,"sps",2,"decide",0); [eq_signal_sd, eq_noise] = eq_.process(Scpe_sig, Symbols); eq_signal_hd = PAMmapper(M,0).quantize(eq_signal_sd); Rx_bits = PAMmapper(M,0).demap(eq_signal_hd); Tx_bits_omitprecode = PAMmapper(M,0).demap(Symbols); [bits,errors,ber_wo,errorIndice] = calc_ber(Rx_bits.signal,Tx_bits_omitprecode.signal); fprintf(["BER w/o precode: %.2d \n"],ber_wo); showErrorBurstCount(eq_signal_hd, Symbols,"displayname",'No Precode','fignum',8); % prior to coding eq_signal_hd = pr.encode(eq_signal_hd); eq_signal_hd = pr.decode(eq_signal_hd); Rx_bits = PAMmapper(M,0).demap(eq_signal_hd); [bits,errors,ber,errorIndice] = calc_ber(Rx_bits.signal,Tx_bits.signal); fprintf(["BER w/ precode: %.2d \n"],ber); showErrorBurstCount(eq_signal_hd, Symbols_plain,"displayname",'Incl. Precode','fignum',7);