condor_data_sim_154a.m

source Matlab traites the UWB

%
%
function [num_err,ber_sim] = ...
    condor_data_sim_154a(FS_CONT,...
                         DATA_LENGTH,RSCODE,PACKET_LENGTH, ...
                         TC,BURST_LENGTH,SYMBOL_LENGTH, ...
                         compound_channel, channel_mask, ...
                         snr_dB,s2,B, ...
                         T_INT,N_INT, ...
                         timing_offset, ...
                         rx_pre_overlap)

% $$$ %
% $$$ % Necessary path
% $$$ addpath ../../matlab/util ../../matlab/rng ../../matlab/pulse ...
% $$$     ../../matlab/receiver ../../matlab/data_signal ...
% $$$     ../../src/channel ../../src/scrambling_timehopping;


fprintf('FS_CONT = %2.0e, DATA_LENGTH = %d\n', ...
        FS_CONT,DATA_LENGTH);
fprintf('TC = %2.1e, BURST_LENGTH = %d, SYMBOL_LENGTH = %d\n', ...
        TC,BURST_LENGTH,SYMBOL_LENGTH);
fprintf('Length of the channel mask = %d\n',length(channel_mask));
fprintf('snr  = %d [dB], B = %2.1e\n',snr_dB,B);
fprintf('T_INT = %2.1e, N_INT = %d\n',T_INT,N_INT);
fprintf('timing_offset = %2.1e\n',timing_offset);
fprintf('Channel Mask = [');
fprintf('%d ',channel_mask);
fprintf(']\n');

if RSCODE == 1
  fullblock = floor(DATA_LENGTH/330);
  PACKET_LENGTH = fullblock*378 + (DATA_LENGTH-fullblock*330) + 48;
  fprintf('RS coding enabled, ');
else
  PACKET_LENGTH = DATA_LENGTH;
  fprintf('No RS coding, ');
end
fprintf('PACKET_LENGTH = %d\n',PACKET_LENGTH);


% Variance of the noise
% $$$ snr    = 10.^(snr_dB/10);
% $$$ Eb     = 1;
% $$$ s2     = Eb ./ (2*snr);

t0 = clock;

% Pre-construction of the data signal of interest
samples = get_samples_values(TC,FS_CONT, ...
                                BURST_LENGTH, ...
                                SYMBOL_LENGTH, ...
                                PACKET_LENGTH);

[ep] = get_ep(PACKET_LENGTH, ...
              SYMBOL_LENGTH, ...
              BURST_LENGTH, ...
              samples);

symbol_start = get_symbol_start(PACKET_LENGTH,samples);

[burst, burstlength] ...
    = condor_init_data_signal(FS_CONT, PACKET_LENGTH, ...
                              TC,BURST_LENGTH,SYMBOL_LENGTH, ...
                              ep.ths, ep.scrambling, samples, ...
                              compound_channel);


% Get the data bit (coded or uncoded)
[tx_bit,data_bit] =  get_tx_bit(DATA_LENGTH,RSCODE,ep.interleaver_seed);

% Get the data signal of interest
[rx_data] ... 
    = get_data_signal(PACKET_LENGTH, ...
                      samples.burst, samples.symbol, burstlength, ...
                      burst,ep.ths,symbol_start,tx_bit);

% Add AWGN
fprintf('add noise, ');
% Parameters for the generation of the Gaussian noise
ALPHA = PACKET_LENGTH/2;
Ts    = TC * SYMBOL_LENGTH;
Nt    = Ts * FS_CONT;
s2    = s2*(2*B)/FS_CONT;
[noise_0 noise_1] = randn_bl(ALPHA,Ts,Nt,B,s2);
rx_data = rx_data + [noise_0 noise_1];
clear noise_0 noise_1;

% Add the end of the preamble at the beginning of the packet
Lch = length(compound_channel);
Lrp = length(rx_pre_overlap);
rx_data = [zeros(1,Lrp-Lch+1) rx_data];
rx_data(1:Lrp) = rx_data(1:Lrp)+rx_pre_overlap;
clear rx_pre_overlap;
% Add noise at the end of the signal
ALPHA = 2;
Nt    = Lrp/2;
Ts    = Nt / FS_CONT;
s2    = s2*(2*B)/FS_CONT;
[noise_0 noise_1] = randn_bl(ALPHA,Ts,Nt,B,s2);
rx_data = [rx_data noise_0 noise_1];
clear noise_0 noise_1;

% Related to the channel mask, necessary for the decoder
channel_mask_unit  = T_INT*N_INT;
% Timing-error stemming from the timing acquisition
timing_offset_samples = (timing_offset*FS_CONT) + (Lrp-Lch+1);
fprintf('timing_offset = %d (samples)\n',timing_offset_samples);


% Receiver
%
fprintf('receive\n');
demod_bit = ed_decoder(rx_data, ep.ths, ...
                       symbol_start, ...
                       0,samples.burst,samples.symbol, ...
                       channel_mask, channel_mask_unit, ...
                       timing_offset_samples, ...
                       PACKET_LENGTH, FS_CONT, T_INT, N_INT);
if RSCODE == 1
  % RS decoding
  dec_bit = rs_decoder_154a(demod_bit,ep.interleaver_seed);
else
  dec_bit = demod_bit;
end

% Compute the BER
num_err = sum(abs(data_bit-dec_bit));
ber_sim = num_err/PACKET_LENGTH;

dt=etime(clock,t0);
fprintf('(dt = %.2f), avg. ber = %.12f\n',dt,mean(ber_sim));