Minor changes from Star PC.

Better plot in channel freq response

imdd_mpi simulation is a good 400G model

DSP offline analysis script

Classes/01_transmit/ChannelFreqResp.m

@@ -240,6 +240,13 @@ classdef ChannelFreqResp < handle
             plot(obj.faxis/1e9, unwrap(angle(1./Havg)),"LineWidth",2,"Color",[0.3467    0.5360    0.6907]) ;
             xlim([0.2 .5*max(obj.faxis)*1e-9]); grid on;
 
+            %%% plot for publication
+            figure(98989);hold all;box on;title('Magnitude Freq. Response');
+            xlim([0.2 .5*max(obj.faxis)*1e-9]);
+            ylim([-20, 2]);
+            plot(obj.faxis/1e9, 20*log10(abs(Havg)),'LineWidth',2);
+            grid on;
+
 
         end