duobinary cleanup (currently it is a mess)

test/memoryless_decoding.m

@@ -0,0 +1,75 @@
+% einstellungen
+M = 4;
+apply_precode_at_tx = 0;
+emulate_precode = 1;
+
+% daten erzeugen
+bitpattern = [];
+s = RandStream('twister','Seed',1);
+for i = 1:log2(M)
+    N = 2^(17-1); %length of prbs
+    bitpattern(:,i) = randi(s,[0 1], N, 1);
+end
+
+if M == 6
+    bitpattern = reshape(bitpattern',[],1);
+    bitpattern = bitpattern(1:end-mod(length(bitpattern),5));
+end
+
+tx_bits = Informationsignal(bitpattern);
+tx_symbols = PAMmapper(M,0).map(tx_bits);
+
+if apply_precode_at_tx
+
+    tx_symbols = Duobinary().precode(tx_symbols);
+
+    if emulate_precode
+        % ansatz 1B) Omit precode (einfach precoded empfangen, nichts weiter machen und normal prozessieren - möglich weil konstellation sich nicht ändert)
+        rx_symbols = tx_symbols;
+        bits_rx = PAMmapper(M,0).demap(rx_symbols);
+        % beachten, dass man die tx_bits anpassen muss, da man ja mit precoded symbolen vergleicht
+        tx_bits = PAMmapper(M,0).demap(tx_symbols);
+    else
+        % ansatz 1A) Precode normal:
+        % Entschiedene Symbole codieren: d_DB(n) = d(n) + d(n-1)    (im Fall von PAM4 7 level [0 1 2 3 4 5 6])
+        symbols_db = Duobinary().encode(tx_symbols);
+        % Entschiedene codierte Symbole decodieren: d_dec(n) = d_DB(n) mod4
+        rx_symbols = Duobinary().decode(symbols_db);
+        bits_rx = PAMmapper(M,0).demap(rx_symbols);
+    end
+
+    [~,~,ber,~] = calc_ber(tx_bits.signal,bits_rx.signal,"skip_front",0,"skip_end",0,"returnErrorLocation",1);
+    disp(['BER: ',sprintf('%.1E',ber)]);
+    assert(ber == 0)
+
+else
+
+    if emulate_precode
+        % emulate precode:
+        % Entschiedene Symbole codieren: d_DB(n) = d(n) + d(n-1)    (im Fall von PAM4 7 level [0 1 2 3 4 5 6])
+        symbols_db = Duobinary().encode(tx_symbols); % das wäre der FFE mit db target
+
+        % Entschiedene codierte Symbole decodieren: d_dec(n) = d_DB(n) mod4
+        rx_symbols = Duobinary().decode(symbols_db); % modulo
+        bits_rx = PAMmapper(M,0).demap(rx_symbols); % demappen
+
+        % ref symbole precoden, auch hier muss man wieder etwas fummeln wegen der emulation:
+        % encode + decode == remove precoding (mathematisch die gleiche operation)
+        tx_symbols_ref = Duobinary().encode(tx_symbols);
+        tx_symbols_ref = Duobinary().decode(tx_symbols_ref);
+        tx_bits = PAMmapper(M,0).demap(tx_symbols_ref);
+        
+    else
+        % normal detection without any precode stuff
+        symbols_db = Duobinary().encode(tx_symbols);
+        
+        rx_symbols = tx_symbols;
+        bits_rx = PAMmapper(M,0).demap(rx_symbols);
+    end
+
+
+    [~,~,ber,~] = calc_ber(tx_bits.signal,bits_rx.signal,"skip_front",1,"skip_end",1,"returnErrorLocation",1);
+    disp(['BER: ',sprintf('%.1E',ber)]);
+    assert(ber == 0)
+end
+