82 lines
2.5 KiB
Matlab
82 lines
2.5 KiB
Matlab
function [eq_package] = duobinary_target(eq_, mlse_,M, rx_signal, tx_symbols, tx_bits, options)
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arguments
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eq_
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mlse_
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M
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rx_signal
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tx_symbols
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tx_bits
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options.precode_mode db_mode
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options.showAnalysis = 0;
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options.eth_style_symbol_mapping = 0;
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end
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%Duobinary Targeting
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[eq_signal, eq_noise] = eq_.process(rx_signal,Duobinary().encode(tx_symbols));
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% dir = [1,1];
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mlse_sig_sd = mlse_.process(eq_signal);
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mlse_sig_hd = PAMmapper(M,0,"eth_style",options.eth_style_symbol_mapping).quantize(mlse_sig_sd);
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% precoding to mitigate error propagation, most prominently used in
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% combination with duobinary signaling to avoid catastrophic error
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% behavior (see J.W.M. Bergmans, Digital Baseband Transmission and Recording -> partial response signaling)
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% takes:
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% -> eq_signal_hd: hard decision signal after eq
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% -> tx_symbols: that where used as reference for eq
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switch options.precode_mode
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case db_mode.db_emulate
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mlse_sig_hd = Duobinary().encode(mlse_sig_hd,"M",M);
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mlse_sig_hd = Duobinary().decode(mlse_sig_hd,"M",M);
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tx_symbols_precoded = Duobinary().encode(tx_symbols);
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tx_symbols_precoded = Duobinary().decode(tx_symbols_precoded);
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tx_bits = PAMmapper(M,0,"eth_style",options.eth_style_symbol_mapping).demap(tx_symbols_precoded);
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case db_mode.db_discard
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% normal dsp for precoded sequence == discard/omit/ignore precode
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tx_bits = PAMmapper(M,0,"eth_style",options.eth_style_symbol_mapping).demap(tx_symbols);
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case db_mode.db_encoded
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% normal DB encoded data (only for 10KM)
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case db_mode.db_precoded
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mlse_sig_hd = Duobinary().encode(mlse_sig_hd,"M",M);
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mlse_sig_hd = Duobinary().decode(mlse_sig_hd,"M",M);
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end
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% M = numel(unique(tx_symbols.signal));
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rx_bits = PAMmapper(M,0,"eth_style",options.eth_style_symbol_mapping).demap(mlse_sig_hd);
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[~,numErrors,ber,~] = calc_ber(rx_bits.signal,tx_bits.signal,"skip_front",100,"skip_end",150,"returnErrorLocation",1);
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eq_package.ber = ber;
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if options.showAnalysis
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eq_noise = eq_noise - mean(eq_noise.signal);
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rx_signal.spectrum("normalizeTo0dB",1,"fignum",250,"displayname","Rx Spectrum");
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Duobinary().encode(tx_symbols).spectrum("normalizeTo0dB",1,"fignum",250,"displayname","DB encoded reference");
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showEQNoisePSD(eq_noise,"fignum",250,"displayname",'Duobinary Target Noise after Equalization');
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fprintf('DB tgt BER: %.2e \n',ber);
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end
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end |