Initial commitHEADmaster

* codec2 cut-down version 1.2.0
* Remove codebook and generation of sources
* remove c2dec c2enc binaries
* prepare for emscripten

1 files changed, 272 insertions, 0 deletions

diff --git a/octave/tofdm.m b/octave/tofdm.m
new file mode 100644
index 0000000..d2b80ce
--- /dev/null
+++ b/octave/tofdm.m
@@ -0,0 +1,272 @@
+% tofdm.m
+% David Rowe and Steve Sampson June 2017
+%
+% Octave script for comparing Octave and C versions of OFDM modem
+%
+% If running from the Octave command line a good idea to clear globals before
+% each run:
+%
+%   octave> clear; tofdm;
+
+% ------------------------------------------------------------------
+
+Nframes = 10;
+sample_clock_offset_ppm = 100;
+foff_hz = 0.5;
+
+more off; format;
+ofdm_lib;
+autotest;
+ldpc
+global passes = 0;
+global fails = 0;
+
+init_cml()
+cml_support = 1
+
+% ---------------------------------------------------------------------
+% Run Octave version 
+% ---------------------------------------------------------------------
+
+% useful to test the modem at other Nc's, but if Nc != 17 we aren't set up for
+% LDPC testing so disable
+if getenv("NC")
+  Nc = str2num(getenv("NC"));
+  cml_support = 0;
+else
+  Nc = 17;
+end
+printf("Nc = %d LDPC testing: %d\n", Nc, cml_support);
+
+config = ofdm_init_mode("700D");
+config.Nc = Nc;
+states = ofdm_init(config);
+states.verbose = 0;
+ofdm_load_const;
+
+printf("Nbitsperframe: %d\n", Nbitsperframe);
+
+if cml_support
+  Nuwtxtsymbolsperframe = (states.Nuwbits+states.Ntxtbits)/bps;
+  S_matrix = [1, j, -j, -1];
+  EsNo = 10;
+  symbol_likelihood_log = bit_likelihood_log = detected_data_log = [];
+
+  % Set up LDPC code
+
+  mod_order = 4; bps = 2; modulation = 'QPSK'; mapping = 'gray';
+  demod_type = 0; decoder_type = 0; max_iterations = 100;
+
+  load HRA_112_112.txt
+  [code_param framesize rate] = ldpc_init_user(HRA_112_112, modulation, mod_order, mapping);
+  assert(Nbitsperframe == (code_param.coded_bits_per_frame + states.Nuwbits + states.Ntxtbits));
+end
+
+tx_bits = zeros(1,Nbitsperframe);
+rand('seed',1);
+
+payload_data_bits = round(rand(1,(Nbitsperframe-Nuwbits-Ntxtbits)/2));
+states.mean_amp = 1;  % start this with something sensible otherwise LDPC decode fails
+if cml_support
+  ibits = payload_data_bits;
+  codeword = LdpcEncode(ibits, code_param.H_rows, code_param.P_matrix);
+  tx_bits(Nuwbits+Ntxtbits+1:end) = codeword;
+  tx_bits(1:Nuwbits+Ntxtbits) = [states.tx_uw zeros(1,Ntxtbits)];
+else
+  tx_bits = create_ldpc_test_frame(states, coded_frame=0);
+end
+
+% Run tx loop
+
+tx_bits_log = []; tx_log = [];
+for f=1:Nframes
+  tx_bits_log = [tx_bits_log tx_bits];
+  tx_log = [tx_log ofdm_mod(states, tx_bits)];
+end
+
+% Channel simulation ----------------------------------------------
+
+rx_log = sample_clock_offset(tx_log, sample_clock_offset_ppm);
+rx_log = freq_shift(rx_log, foff_hz, Fs);
+
+% Rx ---------------------------------------------------------------
+
+% Init rx with ideal timing so we can test with timing estimation disabled
+
+Nsam = length(rx_log);
+prx = 1;
+nin = Nsamperframe+2*(M+Ncp);
+states.rxbuf(Nrxbuf-nin+1:Nrxbuf) = rx_log(prx:nin);
+prx += nin;
+
+rxbuf_log = []; rxbuf_in_log = []; rx_sym_log = []; foff_hz_log = []; 
+timing_est_log = timing_valid_log = timing_mx_log = [];
+coarse_foff_est_hz_log = []; sample_point_log = [];
+phase_est_pilot_log = []; rx_amp_log = [];
+rx_np_log = []; rx_bits_log = [];
+snr_log = []; mean_amp_log = [];
+
+states.timing_en = 1;
+states.foff_est_en = 1;
+states.phase_est_en = 1;
+
+if states.timing_en == 0
+  % manually set ideal timing instant
+  states.sample_point = Ncp;
+end
+
+
+for f=1:Nframes
+
+  % insert samples at end of buffer, set to zero if no samples
+  % available to disable phase estimation on future pilots on last
+  % frame of simulation
+ 
+  nin = states.nin;
+  lnew = min(Nsam-prx+1,nin);
+  rxbuf_in = zeros(1,nin);
+  %printf("nin: %d prx: %d lnew: %d\n", nin, prx, lnew);
+  if lnew
+    rxbuf_in(1:lnew) = rx_log(prx:prx+lnew-1);
+  end
+  prx += lnew;
+
+  [states rx_bits achannel_est_pilot_log arx_np arx_amp] = ofdm_demod(states, rxbuf_in);
+  
+  % log some states for comparison to C
+
+  rxbuf_in_log = [rxbuf_in_log rxbuf_in];
+  rxbuf_log = [rxbuf_log states.rxbuf];
+  rx_sym_log = [rx_sym_log; states.rx_sym];
+  phase_est_pilot_log = [phase_est_pilot_log; angle(achannel_est_pilot_log)];
+  rx_amp_log = [rx_amp_log arx_amp];
+  foff_hz_log = [foff_hz_log; states.foff_est_hz];
+  timing_est_log = [timing_est_log; states.timing_est];
+  timing_valid_log = [timing_valid_log; states.timing_valid];
+  timing_mx_log = [timing_mx_log; states.timing_mx];
+  coarse_foff_est_hz_log = [coarse_foff_est_hz_log; states.coarse_foff_est_hz];
+  sample_point_log = [sample_point_log; states.sample_point];
+  rx_np_log = [rx_np_log arx_np];
+  rx_bits_log = [rx_bits_log rx_bits];
+  mean_amp_log = [mean_amp_log; states.mean_amp];
+  EsNo_estdB = esno_est_calc(arx_np);
+  SNR_estdB = snr_from_esno(states, EsNo_estdB);
+  snr_log = [snr_log; SNR_estdB];
+  
+  % Optional testing of LDPC functions
+
+  if cml_support
+    mean_amp = states.mean_amp;
+    %mean_amp = 1;
+    symbol_likelihood = Demod2D(arx_np(Nuwtxtsymbolsperframe+1:end)/mean_amp, S_matrix, EsNo, arx_amp(Nuwtxtsymbolsperframe+1:end)/mean_amp);
+    bit_likelihood = Somap(symbol_likelihood);
+
+    [x_hat paritychecks] = MpDecode(-bit_likelihood(1:code_param.coded_bits_per_frame), code_param.H_rows, code_param.H_cols, max_iterations, decoder_type, 1, 1);
+    [mx mx_ind] = max(paritychecks);
+    detected_data = x_hat(mx_ind,:);
+    
+    % make sure LDPC decoding is working OK
+    
+    % assert(codeword == detected_data);
+    
+    [m n] = size(symbol_likelihood);
+    symbol_likelihood_log = [symbol_likelihood_log; reshape(symbol_likelihood,m*n,1)];
+    bit_likelihood_log = [bit_likelihood_log; bit_likelihood'];
+    detected_data_log = [detected_data_log detected_data];
+  end
+  
+end
+
+% ---------------------------------------------------------------------
+% Run C version and plot Octave and C states and differences 
+% ---------------------------------------------------------------------
+
+printf("\nRunning C version....\n");
+
+% Override default path by:
+%   1. if running from octave CLI: setting path_to_tofdm = "/your/path/to/tofdm"
+%   2. If running from shell....." set PATH_TO_OFDM = "/your/path/to/tofdm"
+
+if exist("path_to_tofdm", "var") == 0
+  path_to_tofdm = "../build_linux/unittest/tofdm"
+end
+
+if getenv("PATH_TO_TOFDM")
+  path_to_tofdm = getenv("PATH_TO_TOFDM")
+  printf("setting path from env var\n");
+end
+
+path_to_tofdm = sprintf("%s --nc %d", path_to_tofdm, Nc); % append Nc for variable Nc tests
+
+if cml_support == 0
+  path_to_tofdm = sprintf("%s --noldpc", path_to_tofdm);
+end
+
+system(path_to_tofdm);
+load tofdm_out.txt;
+
+fg = 1;
+
+f = figure(fg++); clf; plot(rx_np_log,'+'); title('Octave Scatter Diagram'); axis([-1.5 1.5 -1.5 1.5]);
+f = figure(fg++); clf; plot(rx_np_log_c,'+'); title('C Scatter Diagram'); axis([-1.5 1.5 -1.5 1.5]);
+
+stem_sig_and_error(fg++, 111, tx_bits_log_c, tx_bits_log - tx_bits_log_c, 'tx bits', [1 length(tx_bits_log) -1.5 1.5])
+
+stem_sig_and_error(fg, 211, real(tx_log_c), real(tx_log - tx_log_c), 'tx re', [1 length(tx_log_c) -0.1 0.1])
+stem_sig_and_error(fg++, 212, imag(tx_log_c), imag(tx_log - tx_log_c), 'tx im', [1 length(tx_log_c) -0.1 0.1])
+
+stem_sig_and_error(fg, 211, real(rx_log_c), real(rx_log - rx_log_c), 'rx re', [1 length(rx_log_c) -0.1 0.1])
+stem_sig_and_error(fg++, 212, imag(rx_log_c), imag(rx_log - rx_log_c), 'rx im', [1 length(rx_log_c) -0.1 0.1])
+
+stem_sig_and_error(fg, 211, real(rxbuf_in_log_c), real(rxbuf_in_log - rxbuf_in_log_c), 'rxbuf in re', [1 length(rxbuf_in_log_c) -0.1 0.1])
+stem_sig_and_error(fg++, 212, imag(rxbuf_in_log_c), imag(rxbuf_in_log - rxbuf_in_log_c), 'rxbuf in im', [1 length(rxbuf_in_log_c) -0.1 0.1])
+
+stem_sig_and_error(fg, 211, real(rxbuf_log_c), real(rxbuf_log - rxbuf_log_c), 'rxbuf re', [1 length(rxbuf_log_c) -0.1 0.1])
+stem_sig_and_error(fg++, 212, imag(rxbuf_log_c), imag(rxbuf_log - rxbuf_log_c), 'rxbuf im', [1 length(rxbuf_log_c) -0.1 0.1])
+
+stem_sig_and_error(fg, 211, real(rx_sym_log_c), real(rx_sym_log - rx_sym_log_c), 'rx sym re', [1 length(rx_sym_log_c) -1.5 1.5])
+stem_sig_and_error(fg++, 212, imag(rx_sym_log_c), imag(rx_sym_log - rx_sym_log_c), 'rx sym im', [1 length(rx_sym_log_c) -1.5 1.5])
+
+% for angles pi and -pi are the same
+
+d = phase_est_pilot_log - phase_est_pilot_log_c; d = angle(exp(j*d));
+
+stem_sig_and_error(fg, 211, phase_est_pilot_log_c, d, 'phase est pilot', [1 length(phase_est_pilot_log_c) -1.5 1.5])
+stem_sig_and_error(fg++, 212, rx_amp_log_c, rx_amp_log - rx_amp_log_c, 'rx amp', [1 length(rx_amp_log_c) -1.5 1.5])
+
+stem_sig_and_error(fg  , 211, foff_hz_log_c, (foff_hz_log - foff_hz_log_c), 'foff hz', [1 length(foff_hz_log_c) -1.5 1.5])
+
+stem_sig_and_error(fg++, 212, timing_mx_log_c, (timing_mx_log - timing_mx_log_c), 'timing mx', [1 length(timing_mx_log_c) 0 2])
+
+stem_sig_and_error(fg,   211, timing_est_log_c, (timing_est_log - timing_est_log_c), 'timing est', [1 length(timing_est_log_c) -1.5 1.5])
+stem_sig_and_error(fg++, 212, sample_point_log_c, (sample_point_log - sample_point_log_c), 'sample point', [1 length(sample_point_log_c) -1.5 1.5])
+
+stem_sig_and_error(fg++, 111, rx_bits_log_c, rx_bits_log - rx_bits_log_c, 'rx bits', [1 length(rx_bits_log) -1.5 1.5])
+
+% Run through checklist -----------------------------
+
+check(states.rate_fs_pilot_samples, pilot_samples_c, 'pilot_samples');
+check(tx_bits_log, tx_bits_log_c, 'tx_bits');
+check(tx_log, tx_log_c, 'tx');
+check(rx_log, rx_log_c, 'rx');
+check(rxbuf_in_log, rxbuf_in_log_c, 'rxbuf in');
+check(rxbuf_log, rxbuf_log_c, 'rxbuf');
+check(rx_sym_log, rx_sym_log_c, 'rx_sym', tol=10E-3);
+check(phase_est_pilot_log, phase_est_pilot_log_c, 'phase_est_pilot', tol=1E-2, its_an_angle=1);
+check(rx_amp_log, rx_amp_log_c, 'rx_amp');
+check(timing_est_log, timing_est_log_c, 'timing_est');
+check(timing_valid_log, timing_valid_log_c, 'timing_valid');
+check(timing_mx_log, timing_mx_log_c, 'timing_mx');
+check(coarse_foff_est_hz_log, coarse_foff_est_hz_log_c, 'coarse_foff_est_hz');
+check(sample_point_log, sample_point_log_c, 'sample_point');
+check(foff_hz_log, foff_hz_log_c, 'foff_est_hz');
+check(rx_bits_log, rx_bits_log_c, 'rx_bits');
+if cml_support
+  check(symbol_likelihood_log, symbol_likelihood_log_c, 'symbol_likelihood_log', tol=1E-2);
+  check(bit_likelihood_log, bit_likelihood_log_c, 'bit_likelihood_log');
+  check(detected_data_log, detected_data_log_c, 'detected_data');
+end
+check(mean_amp_log, mean_amp_log_c, 'mean_amp_log');
+check(snr_log, snr_log_c, 'snr_log');
+printf("\npasses: %d fails: %d\n", passes, fails);
+