BCJR implementation

WDM code added (Pol Cont., Opt MUX/DEMUX, Opt Atten, DP_Fiber) -> the codebase is not optimized to always work with dp signals!

Classes/00_signals/Opticalsignal.m

@@ -5,6 +5,7 @@ classdef Opticalsignal < Signal
     properties
         nase
         lambda
+        polrot
 
     end
 
@@ -18,6 +19,7 @@ classdef Opticalsignal < Signal
                 options.logbook
                 options.lambda
                 options.nase
+                options.polrot
             end
 
             obj = obj@Signal(signal);