get_compound_channel.m

source Matlab traites the UWB

function [compound_channel, ch_len] = get_compound_channel(TC,FS_CONT,channel_p,PLOT_DEBUG)

%channel_p.seed depends on RUN, we have to add some more randomness so that it
%is also unique inside this run
channel_p.seed = channel_p.seed + round(100000*rand);

samples_per_chip = TC * FS_CONT;
fs_cont_GHz = FS_CONT / 1e9;

alpha = channel_p.pulse_width; %determines pulse width
[monopulse,t] = get_monopulse(1,channel_p.chip_span,alpha,TC,samples_per_chip);
%monopulse = monopulse./norm(monopulse); %normalize it
% if(PLOT_DEBUG)
%     figure
%     plot(t,monopulse)
% end

% determine pulse -10dB bandwidth
% threshold_dB = -10;
% [Ess,f_high,f_low,BW] = ...
%              cp0702_bandwidth(monopulse,1/FS_CONT,threshold_dB);
%fprintf('-10dB BW = %d [Hz]\n',BW);


%multipath channel
[channel_cont, channel_discr] = ...
  mex_channel(channel_p.model,fs_cont_GHz,channel_p.thld,channel_p.seed);
uoi_channel_discr = channel_discr(:,4)';
%uoi_channel_discr = rand(1,120*fs_cont_GHz);
%uoi_channel_discr = uoi_channel_discr./norm(uoi_channel_discr); %normalize
%apply channel

%calculate the compound channel of pulse shape and channel imp response
compound_channel = conv(uoi_channel_discr,monopulse);
compound_channel = compound_channel ./ norm(compound_channel);
% if(PLOT_DEBUG)
%     figure
%     plot(compound_channel)
%     %also plot its accumulated version
%     
%     squared_channel = compound_channel.^2;
%     
%     %integrate pieces of T ns
%     samples_per_tint = 8e-9 * FS_CONT;
%     %pad the end with zeros so that we can do the reshape
%     squared_channel = zero_pad_reshape(squared_channel,samples_per_tint * 8);
%     channel_int = sum(reshape(squared_channel, samples_per_tint, length(squared_channel) / ...
%                      samples_per_tint),1);
%     channel_int = reshape(repmat(channel_int,samples_per_tint,1),1,length(channel_int)*samples_per_tint);
%     hold on
%     plot(channel_int,'r')
%     
% end

%check whether we have ISI
ch_len = length(compound_channel);

return;