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gnss-sdr/utils/matlab/plot_acq_grid_gsoc.m

81 lines
2.2 KiB
Matlab

% Reads GNSS-SDR Acquisition dump binary file using the provided
% function and plots acquisition grid of acquisition statistic of PRN sat
%
% This function analyzes a experiment performed by Luis Esteve in the framework
% of the Google Summer of Code (GSoC) 2012, with the collaboration of Javier Arribas
% and Carles Fern??ndez, related to the extension of GNSS-SDR to Galileo.
%
% Luis Esteve, 2012. luis(at)epsilon-formacion.com
% -------------------------------------------------------------------------
%
% GNSS-SDR is a Global Navigation Satellite System software-defined receiver.
% This file is part of GNSS-SDR.
%
% Copyright (C) 2010-2019 (see AUTHORS file for a list of contributors)
% SPDX-License-Identifier: GPL-3.0-or-later
%
% -------------------------------------------------------------------------
%
function plot_acq_grid_gsoc(sat)
file=['test_statistics_E_1C_sat_' num2str(sat) '_doppler_0.dat'];
sampling_freq_Hz=4E6
Doppler_max_Hz = 9875
Doppler_min_Hz = -10000
Doppler_step_Hz = 125
% read files
x=read_complex_binary (file);
l_y=length(x);
Doppler_axes=Doppler_min_Hz:Doppler_step_Hz:Doppler_max_Hz;
l_x=length(Doppler_axes);
acq_grid = zeros(l_x,l_y);
index=0;
for k=Doppler_min_Hz:Doppler_step_Hz:Doppler_max_Hz
index=index+1;
filename=['test_statistics_E_1C_sat_' num2str(sat) '_doppler_' num2str(k) '.dat'];
acq_grid(index,:)=abs(read_complex_binary (filename));
end
maximum_correlation_peak = max(max(acq_grid))
[fila,col]=find(acq_grid==max(max(acq_grid)));
delay_error_sps = col -1
Doppler_error_Hz = Doppler_axes(fila)
noise_grid=acq_grid;
delay_span=floor(3*sampling_freq_Hz/(1.023e6));
Doppler_span=floor(500/Doppler_step_Hz);
noise_grid(fila-Doppler_span:fila+Doppler_span,col-delay_span:col+delay_span)=0;
n=numel(noise_grid)-(2*delay_span+1)*(2*Doppler_span+1);
noise_floor= sum(sum(noise_grid))/n
Gain_dbs = 10*log10(maximum_correlation_peak/noise_floor)
%% Plot 3D FULL RESOLUTION
[X,Y] = meshgrid(Doppler_axes,1:1:l_y);
figure;
surf(X,Y,acq_grid');
xlabel('Doppler(Hz)');ylabel('Code Delay(samples)');title(['GLRT statistic of Galileo Parallel Code Phase Search Acquisition. Local replica: E1C cboc PRN ' num2str(sat)]);
end