Many changes

Functions/EQ_structures/duobinary_target.m

@@ -1,17 +1,77 @@
-function [eq_signal,eq_noise,ber,numErrors] = duobinary_target(EQ, MLSE,M, rx_signal, tx_symbols, tx_bits)
+function [eq_package] = duobinary_target(eq_, mlse_,M, rx_signal, tx_symbols, tx_bits, options)
+
+arguments
+    eq_ 
+    mlse_ 
+    M 
+    rx_signal 
+    tx_symbols 
+    tx_bits 
+    options.precode_mode db_mode
+    options.showAnalysis = 0;
+end
     
     %Duobinary Targeting
 
-    [eq_signal, eq_noise] = EQ.process(rx_signal,Duobinary().encode(tx_symbols));
+    [eq_signal, eq_noise] = eq_.process(rx_signal,Duobinary().encode(tx_symbols));
 
     % dir = [1,1];
-    eq_signal = MLSE.process(eq_signal);
+    mlse_sig_sd = mlse_.process(eq_signal);
 
-    eq_signal = Duobinary().decode(eq_signal);
+    mlse_sig_hd = PAMmapper(M,0).quantize(mlse_sig_sd);
+    
+    % precoding to mitigate error propagation, most prominently used in
+    % combination with duobinary signaling to avoid catastrophic error
+    % behavior (see J.W.M. Bergmans, Digital Baseband Transmission and Recording -> partial response signaling)
+
+    % takes: 
+    %   -> eq_signal_hd: hard decision signal after eq
+    %   -> tx_symbols: that where used as reference for eq 
+
+    switch options.precode_mode
+        case db_mode.db_emulate
+
+        mlse_sig_hd = Duobinary().encode(mlse_sig_hd,"M",M);
+        mlse_sig_hd = Duobinary().decode(mlse_sig_hd,"M",M);
+
+        tx_symbols_precoded = Duobinary().encode(tx_symbols);
+        tx_symbols_precoded = Duobinary().decode(tx_symbols_precoded);
+
+        tx_bits = PAMmapper(M,0).demap(tx_symbols_precoded);
+
+        case db_mode.db_discard
+
+        % normal dsp for precoded sequence == discard/omit/ignore precode
+        tx_bits = PAMmapper(M,0).demap(tx_symbols);
+
+        case db_mode.db_encoded
+
+        % normal DB encoded data (only for 10KM)
+
+        case db_mode.db_precoded
+
+        mlse_sig_hd = Duobinary().encode(mlse_sig_hd,"M",M);
+        mlse_sig_hd = Duobinary().decode(mlse_sig_hd,"M",M);
+
+    end
 
     % M = numel(unique(tx_symbols.signal));
-    rx_bits = PAMmapper(M,0).demap(eq_signal);
+    rx_bits = PAMmapper(M,0).demap(mlse_sig_hd);
 
     [~,numErrors,ber,~] = calc_ber(rx_bits.signal,tx_bits.signal,"skip_front",100,"skip_end",150,"returnErrorLocation",1);
+
     
+    eq_package.ber          = ber;
+
+    if options.showAnalysis
+        eq_noise = eq_noise - mean(eq_noise.signal);
+
+rx_signal.spectrum("normalizeTo0dB",1,"fignum",250);
+
+        showEQNoisePSD(eq_noise,"fignum",250,"displayname",'Duobinary Target Noise');
+
+          Duobinary().encode(tx_symbols).spectrum("normalizeTo0dB",1,"fignum",250);
+    end
+
+
 end