gnss-sdr/src/utils/matlab/plot_acq_grid.m

% Reads GNSS-SDR Acquisition dump .mat file using the provided
%  function and plots acquisition grid of acquisition statistic of PRN sat
% Antonio Ramos, 2017. antonio.ramos(at)cttc.es
% -------------------------------------------------------------------------
%
% Copyright (C) 2010-2018  (see AUTHORS file for a list of contributors)
%
% GNSS-SDR is a software defined Global Navigation
%           Satellite Systems receiver
%
% This file is part of GNSS-SDR.
% 
% GNSS-SDR is free software: you can redistribute it and/or modify
% it under the terms of the GNU General Public License as published by
% the Free Software Foundation, either version 3 of the License, or
% at your option) any later version.
% 
% GNSS-SDR is distributed in the hope that it will be useful,
% but WITHOUT ANY WARRANTY; without even the implied warranty of
% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
% GNU General Public License for more details.
%
% You should have received a copy of the GNU General Public License
% along with GNSS-SDR. If not, see <https://www.gnu.org/licenses/>.
%
% -------------------------------------------------------------------------
%

%%%%%%%%% ?????? CONFIGURE !!! %%%%%%%%%%%%%

path = '/home/dmiralles/Documents/gnss-sdr/';
file = 'bds_acq';

sat = 32;

channel = 0;
execution = 3;
% Signal:
%     1 GPS  L1
%     2 GPS  L2M
%     3 GPS  L5
%     4 Gal. E1B
%     5 Gal. E5
%     6 Glo. 1G
%     7 BDS  B1

signal_type = 7;

%%% True for light acq_grid representation
lite_view = true;

%%% If lite_view, it sets the number of samples per chip in the graphical representation
n_samples_per_chip = 3;

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

switch(signal_type)
    case 1
        n_chips = 1023;
        system = 'G';
        signal = '1C';
    case 2
        n_chips = 10230;
        system = 'G';
        signal = '2S';
    case 3
        n_chips = 10230;
        system = 'G';
        signal = 'L5';
    case 4
        n_chips = 4092;
        system = 'E';
        signal = '1B';
    case 5
        n_chips = 10230;
        system = 'E';
        signal = '5X';
    case 6
        n_chips = 511;
        system = 'R';
        signal = '1G';
    case 7
        n_chips = 2046;
        system = 'C';
        signal = 'B1';
end
filename = [path file '_' system '_' signal '_ch_' num2str(channel) '_' num2str(execution) '_sat_' num2str(sat) '.mat'];
load(filename);
[n_fft n_dop_bins] = size(acq_grid);
[d_max f_max] = find(acq_grid == max(max(acq_grid)));
freq = (0 : n_dop_bins - 1) * doppler_step - doppler_max;
delay = (0 : n_fft - 1) / n_fft * n_chips;
figure(1)
if(lite_view == false)
    surf(freq, delay, acq_grid, 'FaceColor', 'interp', 'LineStyle', 'none')
    ylim([min(delay) max(delay)])
else
    delay_interp = (0 : n_samples_per_chip * n_chips - 1) / n_samples_per_chip;
    acq_grid_interp = spline(delay, acq_grid', delay_interp)';
    surf(freq, delay_interp, acq_grid_interp, 'FaceColor', 'interp', 'LineStyle', 'none')
    ylim([min(delay_interp) max(delay_interp)])
end
xlabel('Doppler shift / Hz')
xlim([min(freq) max(freq)])
ylabel('Code delay / chips')
zlabel('Test statistics')
figure(2)
subplot(2,1,1)
plot(freq, acq_grid(d_max, :))
xlim([min(freq) max(freq)])
xlabel('Doppler shift / Hz')
ylabel('Test statistics')
title(['Fixed code delay to ' num2str((d_max - 1) / n_fft * n_chips) ' chips'])
subplot(2,1,2)
normalization = (d_samples_per_code^4) * input_power;
plot(delay, acq_acq_grid(:, f_max)./normalization)
xlim([min(delay) max(delay)])
xlabel('Code delay / chips')
ylabel('Test statistics')
title(['Doppler wipe-off = ' num2str((f_max - 1) * doppler_step - doppler_max) ' Hz'])