% minimal example IM/DD M = 4; fsym = 180e9; 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; Pform = Pulseformer("fsym",fsym,"fdac",4*fsym,"pulse","rrc","pulselength",16,"alpha",rcalpha); [Digi_sig,Symbols,Tx_bits] = PAMsource(... "fsym",fsym,"M",M,"order",18,"useprbs",0,... "fs_out",fdac,... "applyclipping",0,"clipfactor",1.5,... "applypulseform",apply_pulsef,"pulseformer",Pform,... "randkey",random_key,... 'duobinary_mode',duob_mode,... "mrds_code",0,"mrds_blocklength",512).process(); %%%%% AWG El_sig = M8199B("kover",kover).process(Digi_sig); % El_sig = AWG("fdac",fdac,"f_cutoff",fsym,"lpf_active",0,"kover",kover,"bit_resolution",12,"upsampling_method","samplehold","precomp_sinc_rolloff",1).process(Digi_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 = 0.6*(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!? Pform = Pulseformer("fsym",fsym,"fdac",2*fsym,"pulse","rrc","pulselength",16,"alpha",rcalpha,"matched",1); Scpe_sig = Pform.process(Scpe_sig); 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",1); 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)); %% if 1 % -------------------- FFE -------------------- ffe_order = [150, 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); % mu_tr_rls = 9.805e-01; mu_dd_rls = 0.999989348903919; eq_ = FFE("epochs_tr",5,"epochs_dd",5,"len_tr",4096*2,"mu_dd",1e-4,"mu_tr",1.933e-04,"order",ffe_order(1),"sps",2,"decide",0,"optmize_mus",1,"dd_mode",1,"adaption_technique","nlms"); % 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); output.ffe_results = ffe(eq_,M,Scpe_sig,Symbols,Tx_bits, ... "precode_mode",duob_mode,'showAnalysis',1,"postFFE",[], ... "eth_style_symbol_mapping",0); output.ffe_results.metrics.print("description",'DFE'); end %% % -------------------- VNLE + MLSE -------------------- pf_ncoeffs = 1; ffe_order3 = [50, 5, 5]; eq_v = EQ("Ne",ffe_order3,"Nb",dfe_order, ... "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); pf_ = Postfilter("ncoeff",pf_ncoeffs,"useBurg",1); mlse_ = MLSE("duobinary_output",0,'M',M,'trellis_states',PAMmapper(M,0).levels); [output.vnle_results, output.mlse_results] = vnle_postfilter_mlse(eq_v, pf_, mlse_, M, Scpe_sig, Symbols, Tx_bits, ... "precode_mode", duob_mode, 'showAnalysis', 1, "postFFE", [], "eth_style_symbol_mapping", 0); output.mlse_results.metrics.print("description",'MLSE'); %% % -------------------- DB target -------------------- mlse_db_ = MLSE("DIR",[1,1],"duobinary_output",0,"M",M,'trellis_states',PAMmapper(M,0).levels); ffe_order = [50, 5, 5]; eq_ = EQ("Ne",ffe_order,"Nb",dfe_order,"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); output.dbt_results = duobinary_target(eq_,mlse_db_, M, Scpe_sig, Symbols, Tx_bits, ... "precode_mode", duob_mode, 'showAnalysis', 0, "postFFE", []); output.dbt_results.metrics.print("description",'Duobinary');