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restructure and organize

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This commit is contained in:
Silas Oettinghaus
2026-06-22 22:58:35 +02:00
parent 3603fd7853
commit c4f75b7ec4
10 changed files with 108 additions and 116 deletions
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189
Functions/EQ_blocks/duobinary_target.m Normal file
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function [db_results] = 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;
options.eth_style_symbol_mapping = 0;
options.postFFE = [];
options.decoding_mode db_decoder = db_decoder.sequencedetection;
end
%Duobinary Targeting
db_ref_sequence = Duobinary().encode(tx_symbols);
db_ref_constellation = unique(db_ref_sequence.signal);
[eq_signal, eq_noise] = eq_.process(rx_signal,db_ref_sequence);
if ~isempty(options.postFFE)
[eq_signal,eq_noise] = options.postFFE.process(eq_signal,db_ref_sequence);
end
%
switch options.decoding_mode
case db_decoder.sequencedetection %MLSE
mlse_.DIR = [1,1];
if isa(mlse_,'MLSE_viterbi')
mlse_sig_sd = mlse_.process(eq_signal);
else
[mlse_sig_sd,LLR,GMI_MLSE] = mlse_.process(eq_signal,tx_symbols);
end
pam_sig_hd = PAMmapper(M,0,"eth_style",options.eth_style_symbol_mapping).quantize(mlse_sig_sd);
case db_decoder.memoryless %DB Target FFE
% Hard decision on FFE output
eq_signal_hd = PAMmapper(M, 0).quantize(eq_signal,'custom_const',db_ref_constellation.');
eq_signal_hd = Duobinary().decode(eq_signal_hd);
pam_sig_hd = eq_signal_hd;
% tx_symbols = Duobinary().encode(tx_symbols);
% tx_symbols = Duobinary().decode(tx_symbols.*db_const_scale_factor);
end
% 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)
switch options.precode_mode
case db_mode.no_db
% TX Data is not precoded:
% A) Emulate diff precoding
switch options.decoding_mode
case db_decoder.sequencedetection %MLSE
mlse_sig_hd_precoded = Duobinary().encode(pam_sig_hd);
mlse_sig_hd_precoded = Duobinary().decode(mlse_sig_hd_precoded);
case db_decoder.memoryless %DB Target FFE
% mlse_sig_hd_precoded = Duobinary().encode(pam_sig_hd);
% mlse_sig_hd_precoded = Duobinary().decode(mlse_sig_hd_precoded);
mlse_sig_hd_precoded = pam_sig_hd;
end
tx_symbols_precoded = Duobinary().encode(tx_symbols);
tx_symbols_precoded = Duobinary().decode(tx_symbols_precoded);
tx_bits_precoded = PAMmapper(M,0,"eth_style",options.eth_style_symbol_mapping).demap(tx_symbols_precoded);
rx_bits_mlse = PAMmapper(M,0,"eth_style",options.eth_style_symbol_mapping).demap(mlse_sig_hd_precoded);
[~,errors_db_diff_precoded,ber_db_diff_precoded,~] = calc_ber(rx_bits_mlse.signal,tx_bits_precoded.signal,"skip_front",100,"skip_end",150,"returnErrorLocation",1);
%B) Just determine BER
rx_bits_mlse = PAMmapper(M,0,"eth_style",options.eth_style_symbol_mapping).demap(pam_sig_hd);
tx_bits = PAMmapper(M,0,"eth_style",options.eth_style_symbol_mapping).demap(tx_symbols);
[bits_mlse,errors_mlse,ber_db,~] = calc_ber(rx_bits_mlse.signal,tx_bits.signal,"skip_front",100,"skip_end",150,"returnErrorLocation",1);
case db_mode.db_precoded
% Daten SIND TATSÄCHLICH precoded auf TX Seite:
% A) Decode at Rx if no DB targeting was applied (we are in VNLE or MLSE EQ structure here!
switch options.decoding_mode
case db_decoder.sequencedetection %MLSE
mlse_sig_hd_decoded = Duobinary().encode(pam_sig_hd,"M",M);
mlse_sig_hd_decoded = Duobinary().decode(mlse_sig_hd_decoded,"M",M);
case db_decoder.memoryless %DB Target FFE
mlse_sig_hd_decoded = pam_sig_hd;
end
tx_symbols_precoded = Duobinary().encode(tx_symbols,"M",M);
tx_symbols_precoded = Duobinary().decode(tx_symbols_precoded,"M",M);
tx_bits_precoded = PAMmapper(M,0,"eth_style",options.eth_style_symbol_mapping).demap(tx_symbols_precoded);
rx_bits_mlse_decoded = PAMmapper(M,0,"eth_style",options.eth_style_symbol_mapping).demap(mlse_sig_hd_decoded);
[~,errors_db_diff_precoded,ber_db_diff_precoded,a] = calc_ber(rx_bits_mlse_decoded.signal,tx_bits_precoded.signal,"skip_front",100,"skip_end",150,"returnErrorLocation",1);
burst_db_precoded = count_error_bursts(a, 40);
% B) Omit the Coding by comparing with demapped TX symbol sequence
tx_bits = PAMmapper(M,0,"eth_style",options.eth_style_symbol_mapping).demap(tx_symbols);
rx_bits_mlse = PAMmapper(M,0,"eth_style",options.eth_style_symbol_mapping).demap(pam_sig_hd);
[bits_db,errors_db,ber_db,a] = calc_ber(rx_bits_mlse.signal,tx_bits.signal,"skip_front",100,"skip_end",150,"returnErrorLocation",1);
burst_db = count_error_bursts(a, 40);
cols = linspecer(8);
figure();hold on;
stem(1:40,burst_db,'LineWidth',1,'Color',cols(4,:),'Marker','_','DisplayName','w/o diff. precoder');
stem(1:40,burst_db_precoded,'LineWidth',1,'Color',cols(3,:),'Marker','.','LineStyle','-','DisplayName','w diff. precoder');
xlabel('Bit Error Burst Length')
ylabel('Occurence')
set(gca, 'yscale', 'log');
end
% M = numel(unique(tx_symbols.signal));
rx_bits = PAMmapper(M,0,"eth_style",options.eth_style_symbol_mapping).demap(pam_sig_hd);
[bits_db,errors_db,ber_db,errorIndice_db] = calc_ber(rx_bits.signal,tx_bits.signal,"skip_front",100,"skip_end",150,"returnErrorLocation",1);
alpha = arburg(eq_noise.signal,1);%pf_.coefficients(2);
alpha = alpha(2);
switch options.decoding_mode
case db_decoder.sequencedetection %MLSE
if isa(mlse_,'MLSE_viterbi')
gmi_mlse = NaN;
air_mlse = NaN;
else
gmi_mlse = GMI_MLSE;
air_mlse = tx_symbols.fs .* floor(log2(double(M))*10)/10 .* gmi_mlse ./ log2(double(M));
end
case db_decoder.memoryless %DB Target FFE
% [gmi] = calc_air(eq_signal_sd, tx_symbols, "skip_front", 10000, "skip_end", 10000);
[gmi] = calc_ngmi(eq_signal,tx_symbols);
gmi_mlse = max(gmi,0);
air_mlse = tx_symbols.fs .* floor(log2(double(M))*10)/10 .* gmi ./ log2(double(M));
end
db_results = struct();
db_results.metrics = Metricstruct;
db_results.metrics.result_id = NaN;
db_results.metrics.run_id = NaN;
db_results.metrics.eqParam_id = NaN;
db_results.metrics.date_of_processing = datetime('now');
db_results.metrics.BER = ber_db;
db_results.metrics.numBits = bits_db;
db_results.metrics.numBitErr = errors_db;
db_results.metrics.BER_precoded = ber_db_diff_precoded;
db_results.metrics.numBitErr_precoded = errors_db_diff_precoded;
db_results.metrics.GMI = gmi_mlse;
db_results.metrics.AIR = air_mlse;
db_results.metrics.MLSE_dir = mlse_.DIR;
db_results.metrics.Alpha = alpha;
% Create DB results structure
db_results.config = Equalizerstruct();
eq_.e = [];
eq_.e2 = [];
eq_.e3 = [];
db_results.config.eq = jsonencode(eq_);
% mlse_.DIR = [];
db_results.config.mlse = jsonencode(mlse_);
db_results.config.equalizer_structure = int32(equalizer_structure.vnle_db_mlse);
db_results.config.comment = 'function: Duobinary tgt. (VNLE -> MLSE)';
if options.showAnalysis
eq_signal.eye(eq_signal.fs,M,"fignum",249);
eq_noise = eq_noise - mean(eq_noise.signal);
rx_signal.spectrum("normalizeTo0dB",1,"fignum",250,"displayname","Rx Spectrum");
Duobinary().encode(tx_symbols).spectrum("normalizeTo0dB",1,"fignum",250,"displayname","DB encoded reference");
showEQNoisePSD(eq_noise,"fignum",250,"displayname",'Duobinary Target Noise after Equalization');
fprintf('DB tgt BER: %.2e \n',ber_db);
figure(341); clf;
tx_symbols_uncoded = Duobinary().decode(db_ref_sequence);
showLevelHistogram(eq_signal, db_ref_sequence, "fignum", 341,"ref_symbol_uncoded",tx_symbols_uncoded);
end
end