106 lines
2.8 KiB
Matlab
106 lines
2.8 KiB
Matlab
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datarate = 112e9;
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M = 6;
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laser_linewidth = 0;
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kover = 32;
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fsym = round(datarate*1e-9 / log2(M))*1e9;
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fdac = 256e9;
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% 1) PRBS Generation
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O = 18; %order of prbs
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N = 2^(O-1); %length of prbs
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[~,seed] = prbs(O,1); %initialize first seed of prbs
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bitpattern=[];
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for i = 1:log2(M)
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[bitpattern(:,i),seed] = prbs(O,N,seed);
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end
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if M == 6
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bitpattern = reshape(bitpattern,[],1);
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bitpattern = bitpattern(1:end-mod(length(bitpattern),5));
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end
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% 2 ) Build Inf. signal class
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bits = Informationsignal(bitpattern);
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alphas = flip([0.01,0.05,0.1,0.2,0.3,0.4]);
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LP_awg = Filter('filtdegree',5,"f_cutoff",70e9,"fs",fdac*kover,"filterType",filtertypes.butterworth);
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AWG_=AWG("fdac",fdac,"dac_min",-1,"dac_max",1,"H_lpf",LP_awg,"kover",kover,"bit_resolution",16,"lpf_active",1,"normalize2dac",1,"upsampling_method","samplehold");
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% 3) Digi modulation -> PAM-M signal
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digimod_out = PAMmapper(M,0).map(bits);
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digimod_out.fs = fsym;
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X = Pulseformer("fsym",fsym,"fdac",fdac,"pulse","rrc","pulselength",16,"rrcalpha",alphas(a)).process(digimod_out);
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% plot_eye(X.signal,X.fs,fsym);
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% 5) AWG (lowpass, quantization, sample and hold)
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X = AWG_.process(X);
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f=figure(12);
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f.Name = 'spectrum';
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spectrum_plot(X.signal,X.fs,'spectrum');
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figure(4)
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LP_awg.showHere();
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disp(['El. power: ',num2str(X.power),' dBm (into 50 Ohm)']);
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disp(['El. RMS voltage: ',num2str(sqrt(mean(X.signal.^2))),' V']);
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disp(['max voltage: ',num2str(max(X.signal)),' V']);
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rms_ = rms(X.signal);
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max_ = max(X.signal);
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min_ = min(X.signal);
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figure(1);
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hold on
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plot(X.signal,'LineWidth',0.1);
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yline([max_, min_],'LineWidth',2,'LineStyle','--');
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yline([rms_, -rms_],'LineWidth',2,'LineStyle',':');
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ylim([-3 3]);
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title(['AWG output: ',num2str(X.power), 'dBm']);
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f=figure(12);
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f.Name = 'spectrum';
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spectrum_plot(X.signal,X.fs,'spectrum');
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% 6) Lowpass behavior before laser
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LP_modulator= Filter('filtdegree',4,"f_cutoff",70e9,"fs",fdac*kover,"filterType",filtertypes.butterworth);
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X = LP_modulator.process(X);
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% 7) Normalize signal to 0dB rms
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figure(1);subplot(1,2,1);plot(X.signal,'LineWidth',0.1);ylim([-3 3]);title(['AWG output: ',num2str(X.power), 'dBm into 50 Ohm']);
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% 1) Laser; Modulation -> OPTICAL DOMAIN
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u_pi = 2;
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vbias = -1;
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extmodlaser = EML("mode",eml_mode.im_cosinus,"power",0,"fsimu",X.fs,"lambda",1290,"bias",vbias,"u_pi",u_pi,"linewidth",laser_linewidth,"randomkey",5);
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E = X.normalize("mode","oneone");
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figure(1);subplot(1,2,2);plot(E.signal,'LineWidth',0.1);ylim([-3 3]);title(['scaled to modulator; ',num2str(E.power), 'dBm']);
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disp(['El. power: ',num2str(E.power),' dBm (into 50 Ohm)']);
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[Opt,extmodlaser] = extmodlaser.process(E);
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f=figure(12);
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f.Name = 'spectrum';
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spectrum_plot(X.signal,X.fs,'spectrum');
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plot_eye(E.signal,E.fs,fsym);
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figure(111)
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hold on
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scatter(E.signal(1:100000),(abs(Opt.signal(1:100000)).^2)*1e3,0.1,'.','DisplayName','Modulator TF')
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xlabel('Input in V')
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ylabel('Output in mW')
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