mirrors
/
gnss-sdr
mirror of https://github.com/gnss-sdr/gnss-sdr
1
0
Fork 0
Code Issues Releases Wiki Activity

Improving SPIR GSS6450 signal source

This commit is contained in:
Javier Arribas 2018-11-29 17:53:01 +01:00
parent 514b9dd35f
commit 1302614613
3 changed files with 77 additions and 47 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
src/algorithms/signal_source/adapters/spir_gss6450_file_signal_source.cc
View File

@ -153,7 +153,8 @@ SpirGSS6450FileSignalSource::SpirGSS6450FileSignalSource(ConfigurationInterface*
valve_vec_.push_back(gnss_sdr_make_valve(sizeof(gr_complex), samples_, queue_));
if (dump_)
{
sink_vec_.push_back(gr::blocks::file_sink::make(sizeof(gr_complex), dump_filename_.c_str()));
std::string tmp_str = dump_filename_ + "_ch" + std::to_string(i);
sink_vec_.push_back(gr::blocks::file_sink::make(sizeof(gr_complex), tmp_str.c_str()));
}
if (enable_throttle_control_)
{

112
src/algorithms/signal_source/gnuradio_blocks/unpack_spir_gss6450_samples.cc
View File

@ -3,6 +3,7 @@
*
* \brief Unpacks SPIR int samples
* \author Antonio Ramos, antonio(at)cttc.es
* \author Javier Arribas jarribas (at) cttc.es
* -------------------------------------------------------------------------
*
* Copyright (C) 2010-2018 (see AUTHORS file for a list of contributors)
@ -45,10 +46,6 @@ unpack_spir_gss6450_samples::unpack_spir_gss6450_samples(unsigned int adc_nbit)
{
adc_bits = adc_nbit;
samples_per_int = 16 / adc_bits;
i_data.resize(adc_bits, false);
q_data.resize(adc_bits, false);
adc_bits_two_pow = static_cast<int>(std::exp2(adc_bits));
two_compl_thres = adc_bits_two_pow / 2;
}
@ -56,50 +53,87 @@ unpack_spir_gss6450_samples::~unpack_spir_gss6450_samples()
{
}
int unpack_spir_gss6450_samples::compute_two_complement(unsigned long data)
void unpack_spir_gss6450_samples::decode_4bits_word(uint32_t input_uint32, gr_complex* out, int adc_bits)
{
int res = 0;
if (static_cast<int>(data) < two_compl_thres)
int8_t tmp_char;
float Q;
float I;
switch (adc_bits)
{
res = static_cast<int>(data);
}
else
{
res = static_cast<int>(data) - adc_bits_two_pow;
}
return res;
}
case 2:
//four bits per complex sample (2 I + 2 Q), 8 samples per int32[s0,s1,s2,s3,s4,s5,s6,s7]
for (int i = 0; i < 8; i++)
{
tmp_char = input_uint32 & 3;
if (tmp_char >= 2)
{
I = (tmp_char - 4);
}
else
{
I = tmp_char;
}
input_uint32 = input_uint32 >> 2;
tmp_char = input_uint32 & 3;
if (tmp_char >= 2)
{
Q = (tmp_char - 4);
}
else
{
Q = tmp_char;
}
input_uint32 = input_uint32 >> 2;
out[7 - i] = gr_complex(I, Q);
}
break;
case 4:
//eight bits per complex sample (4 I + 4 Q), 4 samples per int32= [s0,s1,s2,s3]
for (int i = 0; i < 4; i++)
{
tmp_char = input_uint32 & 0x0F;
if (tmp_char >= 8)
{
I = (tmp_char - 16);
}
else
{
I = tmp_char;
}
input_uint32 = input_uint32 >> 4;
tmp_char = input_uint32 & 0x0F;
if (tmp_char >= 8)
{
Q = (tmp_char - 16);
}
else
{
Q = tmp_char;
}
input_uint32 = input_uint32 >> 4;
out[3 - i] = gr_complex(I, Q);
}
break;
}
}
int unpack_spir_gss6450_samples::work(int noutput_items,
gr_vector_const_void_star& input_items, gr_vector_void_star& output_items)
{
const int* in = reinterpret_cast<const int*>(input_items[0]);
const int32_t* in = reinterpret_cast<const int32_t*>(input_items[0]);
gr_complex* out = reinterpret_cast<gr_complex*>(output_items[0]);
unsigned int n_sample = 0;
unsigned int in_counter = 0;
std::bitset<32> bs;
for (int i = 0; i < noutput_items; i++)
int n_sample = 0;
int in_counter = 0;
do
{
bs = in[in_counter];
int i_shift = adc_bits * 2 * (samples_per_int - n_sample - 1) + adc_bits;
int q_shift = adc_bits * 2 * (samples_per_int - n_sample - 1);
for (unsigned int k = 0; k < adc_bits; k++)
{
i_data[k] = bs[i_shift + k];
q_data[k] = bs[q_shift + k];
}
//out[i] = gr_complex(static_cast<float>(compute_two_complement(i_data.to_ulong())) + 0.5,
// static_cast<float>(compute_two_complement(q_data.to_ulong())) + 0.5);
out[i] = gr_complex(static_cast<float>(compute_two_complement(q_data.to_ulong())) + 0.5,
static_cast<float>(compute_two_complement(i_data.to_ulong())) + 0.5);
n_sample++;
if (n_sample == samples_per_int)
{
n_sample = 0;
in_counter++;
}
decode_4bits_word(in[in_counter++], &out[n_sample], adc_bits);
n_sample += samples_per_int;
}
while (n_sample < noutput_items);
return noutput_items;
}

9
src/algorithms/signal_source/gnuradio_blocks/unpack_spir_gss6450_samples.h
View File

@ -3,6 +3,7 @@
*
* \brief Unpacks SPIR int samples
* \author Antonio Ramos, antonio.ramos(at)cttc.es
* \author Javier Arribas jarribas (at) cttc.es
* -------------------------------------------------------------------------
*
* Copyright (C) 2010-2018 (see AUTHORS file for a list of contributors)
@ -32,7 +33,6 @@
#define GNSS_SDR_UNPACK_SPIR_GSS6450_SAMPLES_H
#include <gnuradio/sync_interpolator.h>
#include <boost/dynamic_bitset.hpp>
class unpack_spir_gss6450_samples;
@ -47,18 +47,13 @@ public:
int work(int noutput_items,
gr_vector_const_void_star &input_items, gr_vector_void_star &output_items);
friend unpack_spir_gss6450_samples_sptr make_unpack_spir_gss6450_samples_sptr(unsigned int adc_nbit);
void decode_4bits_word(uint32_t input_int32, gr_complex *out, int adc_bits);
unpack_spir_gss6450_samples(unsigned int adc_nbit);
~unpack_spir_gss6450_samples();
private:
int compute_two_complement(unsigned long data);
unsigned int adc_bits;
unsigned int samples_per_int;
int two_compl_thres;
int adc_bits_two_pow;
boost::dynamic_bitset<> i_data;
boost::dynamic_bitset<> q_data;
};
#endif