Files
imdd_silas/projects/db_minimal_example.m
magf 3676d92b30 +++ Changes +++
+ duobinary_target now supports memoryless decoding (FFE targets DB response without MLSE)
+ PAMmapper.quantize now supports custom constellations for quantization
+ Added a new folder 'Documentations' for pdfs, slides, etc.
+ Added new FSO evaluation scripts in projects/FSO transmission/Evaluation Scripts
+ Added ffe_db (rudimentary module, not important anymore)
2026-03-05 10:41:36 +01:00

71 lines
2.3 KiB
Matlab

% einstellungen
M = 2;
apply_precode_at_tx = 0;
% 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
% Precode
tx_symbols_precoded = Duobinary().precode(tx_symbols);
% 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_precoded);
% 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);
figure(1)
clf
hold on
stairs(tx_symbols.signal(1:100),'DisplayName','Tx Symbols','LineStyle','-','LineWidth',2);
stairs(rx_symbols.signal(1:100),'DisplayName','Rx Symbols','LineStyle',':','LineWidth',1);
legend
ylim([-2 2])
[~,~,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
% 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);
% ref symbole precoden:
tx_symbols_ref = Duobinary().encode(tx_symbols);
tx_symbols_ref = Duobinary().decode(tx_symbols_ref);
tx_bits_ref = PAMmapper(M,0).demap(tx_symbols_ref);
% step plot to check visually if symbols overlap
figure(1)
clf
hold on
stairs(tx_symbols_ref.signal(1:100),'DisplayName','Tx Symbols','LineStyle','-','LineWidth',2);
stairs(rx_symbols.signal(1:100),'DisplayName','Rx Symbols','LineStyle',':','LineWidth',1);
legend
ylim([-2 2])
[~,~,ber,~] = calc_ber(tx_bits_ref.signal,bits_rx.signal,"skip_front",1,"skip_end",1,"returnErrorLocation",1);
disp(['BER: ',sprintf('%.1E',ber)]);
assert(ber == 0)
end