fep=fopen("errors_450.bin","wb"); fwrite(fep, sim_qpsk_hf.ldpc_errors_log, "short"); fclose(fep);
endfunction
+% Rate Fs test
+
+function test_rate_Fs(tx_filename)
+ sim_in = standard_init();
+
+ sim_in.verbose = 1;
+ sim_in.plot_scatter = 1;
+
+ sim_in.framesize = 576;
+ sim_in.Nc = 2;
+ sim_in.Rs = 250;
+ sim_in.Ns = 6;
+ sim_in.Np = 4;
+ sim_in.Nchip = 1;
+ sim_in.ldpc_code_rate = 0.5;
+ sim_in.ldpc_code = 1;
+
+ sim_in.Ntrials = 10;
+ sim_in.Esvec = 7;
+ sim_in.hf_sim = 1;
+ sim_in.hf_mag_only = 0;
+ sim_in.modulation = 'qpsk';
+
+ sim_in = symbol_rate_init(sim_in);
+
+ prev_sym_tx = sim_in.prev_sym_tx;
+ prev_sym_rx = sim_in.prev_sym_rx;
+ code_param = sim_in.code_param;
+ tx_bits_buf = sim_in.tx_bits_buf;
+ framesize = sim_in.framesize;
+ rate = sim_in.ldpc_code_rate;
+ Ntrials = sim_in.Ntrials;
+ Rs = sim_in.Rs;
+ Fs = sim_in.Fs;
+ Nc = sim_in.Nc;
+
+ M = Fs/Rs;
+
+ EsNodB = sim_in.Esvec(1);
+ EsNo = 10^(EsNodB/10);
+
+ rx_symb_log = []; av_tx_pwr = [];
+ Terrs = Tbits = 0;
+ errors_log = []; Nerrs_log = [];
+ ldpc_Nerrs_log = []; ldpc_errors_log = [];
+ Ferrsldpc = Terrsldpc = Tbitsldpc = 0;
+
+ rn_coeff = gen_rn_coeffs(0.5, 1/Fs, Rs, 6, M);
+ tx_symb_buf = [];
+
+ for nn=1:Ntrials+2
+
+ % modulator ---------------------------------------------------------------------
+
+ tx_bits = round(rand(1,framesize*rate));
+ [tx_symb tx_bits prev_sym_tx] = symbol_rate_tx(sim_in, tx_bits, code_param, prev_sym_tx);
+ tx_bits_buf(1:framesize) = tx_bits_buf(framesize+1:2*framesize);
+ tx_bits_buf(framesize+1:2*framesize) = tx_bits;
+ tx_symb_buf = [tx_symb_buf; tx_symb];
+
+ s_ch = tx_symb;
+ [rx_symb rx_bits rx_symb_linear amp_linear amp_ phi_ prev_sym_rx sim_in] = symbol_rate_rx(sim_in, s_ch, prev_sym_rx);
+
+ % wait 2 frames so phi_ and amp_ are valid
+
+ if nn > 2
+ rx_symb_log = [rx_symb_log rx_symb_linear];
+
+ % Measure BER
+
+ error_positions = xor(rx_bits, tx_bits_buf(1:framesize));
+ Nerrs = sum(error_positions);
+ Terrs += Nerrs;
+ Tbits += length(tx_bits);
+ errors_log = [errors_log error_positions];
+ Nerrs_log = [Nerrs_log Nerrs];
+
+ % LDPC decode
+
+ detected_data = ldpc_dec(code_param, sim_in.max_iterations, sim_in.demod_type, sim_in.decoder_type, ...
+ rx_symb_linear, min(100,EsNo), amp_linear);
+ error_positions = xor( detected_data(1:framesize*rate), tx_bits_buf(1:framesize*rate) );
+ Nerrs = sum(error_positions);
+ ldpc_Nerrs_log = [ldpc_Nerrs_log Nerrs];
+ ldpc_errors_log = [ldpc_errors_log error_positions];
+ if Nerrs
+ Ferrsldpc++;
+ end
+ Terrsldpc += Nerrs;
+ Tbitsldpc += framesize*rate;
+ end
+ end
+
+ printf("EsNo (dB): %3.1f Terrs: %d BER %4.2f QPSK BER theory %4.2f av_tx_pwr: %3.2f", EsNodB, Terrs,
+ Terrs/Tbits, 0.5*erfc(sqrt(EsNo/2)), av_tx_pwr);
+ printf("\n LDPC: Terrs: %d BER: %4.2f Ferrs: %d FER: %4.2f\n",
+ Terrsldpc, Terrsldpc/Tbitsldpc, Ferrsldpc, Ferrsldpc/Ntrials);
+
+ % zero pad and tx filter
+
+ [m n] = size(tx_symb_buf);
+ zp = [];
+ for i=1:m
+ zrow = M*tx_symb_buf(i,:);
+ zp = [zp; zrow; zeros(M-1,Nc)];
+ end
+
+ for c=1:Nc
+ tx_filt(:,c) = filter(rn_coeff, 1, zp(:,c));
+ end
+
+ % upconvert to real IF and save to disk
+
+ [m n] = size(tx_filt);
+ tx_fdm = zeros(1,m);
+ Fc = 1500;
+ freq(1) = exp(j*2*pi*(Fc - Rs*0.75)/Fs);
+ freq(2) = exp(j*2*pi*(Fc + Rs*0.75)/Fs);
+ phase_tx = ones(1,Nc);
+
+ for c=1:Nc
+ for i=1:m
+ phase_tx(c) = phase_tx(c) * freq(c);
+ tx_fdm(i) = tx_fdm(i) + tx_filt(i,c)*phase_tx(c);
+ end
+ end
+
+ Ascale = 10000;
+ figure(1);
+ clf;
+ plot(Ascale*real(tx_fdm))
+
+ ftx=fopen(tx_filename,"wb"); fwrite(ftx, Ascale*real(tx_fdm), "short"); fclose(ftx);
+
+endfunction
% Start simulations ---------------------------------------
more off;
%test_curves();
-test_single();
+%test_single();
+test_rate_Fs("tx.raw");