gnss-sdr/src/algorithms/tracking/libs/fpga_multicorrelator_8sc.cc

430 lines
13 KiB
C++

/*!
* \file fpga_multicorrelator_8sc.cc
* \brief High optimized FPGA vector correlator class
* \authors <ul>
* <li> Marc Majoral, 2017. mmajoral(at)cttc.cat
* <li> Javier Arribas, 2015. jarribas(at)cttc.es
* </ul>
*
* Class that controls and executes a high optimized vector correlator
* class in the FPGA
*
* -------------------------------------------------------------------------
*
* Copyright (C) 2010-2017 (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 <http://www.gnu.org/licenses/>.
*
* -------------------------------------------------------------------------
*/
#include "fpga_multicorrelator_8sc.h"
#include <cmath>
// FPGA stuff
#include <new>
// libraries used by DMA test code and GIPO test code
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
// libraries used by DMA test code
#include <sys/stat.h>
#include <stdint.h>
#include <unistd.h>
#include <assert.h>
// libraries used by GPIO test code
#include <stdlib.h>
#include <signal.h>
#include <sys/mman.h>
// logging
#include <glog/logging.h>
// string manipulation
#include <string>
#define PAGE_SIZE 0x10000
#define MAX_LENGTH_DEVICEIO_NAME 50
#define CODE_RESAMPLER_NUM_BITS_PRECISION 20
#define CODE_PHASE_STEP_CHIPS_NUM_NBITS CODE_RESAMPLER_NUM_BITS_PRECISION
#define pwrtwo(x) (1 << (x))
#define MAX_CODE_RESAMPLER_COUNTER pwrtwo(CODE_PHASE_STEP_CHIPS_NUM_NBITS) // 2^CODE_PHASE_STEP_CHIPS_NUM_NBITS
#define PHASE_CARR_NBITS 32
#define PHASE_CARR_NBITS_INT 1
#define PHASE_CARR_NBITS_FRAC PHASE_CARR_NBITS - PHASE_CARR_NBITS_INT
#define LOCAL_CODE_FPGA_CORRELATOR_SELECT_COUNT 0x20000000
#define LOCAL_CODE_FPGA_CLEAR_ADDRESS_COUNTER 0x10000000
#define LOCAL_CODE_FPGA_ENABLE_WRITE_MEMORY 0x0C000000
#define TEST_REGISTER_TRACK_WRITEVAL 0x55AA
void fpga_multicorrelator_8sc::set_initial_sample(int samples_offset)
{
d_initial_sample_counter = samples_offset;
}
bool fpga_multicorrelator_8sc::set_local_code_and_taps(int code_length_chips,
const lv_16sc_t* local_code_in, float* shifts_chips)
{
d_local_code_in = local_code_in;
d_shifts_chips = shifts_chips;
d_code_length_chips = code_length_chips;
fpga_multicorrelator_8sc::fpga_configure_tracking_gps_local_code();
return true;
}
bool fpga_multicorrelator_8sc::set_output_vectors(lv_16sc_t* corr_out)
{
// Save CPU pointers
d_corr_out = corr_out;
return true;
}
void fpga_multicorrelator_8sc::update_local_code(float rem_code_phase_chips)
{
d_rem_code_phase_chips = rem_code_phase_chips;
fpga_multicorrelator_8sc::fpga_compute_code_shift_parameters();
fpga_multicorrelator_8sc::fpga_configure_code_parameters_in_fpga();
}
bool fpga_multicorrelator_8sc::Carrier_wipeoff_multicorrelator_resampler(
float rem_carrier_phase_in_rad, float phase_step_rad,
float rem_code_phase_chips, float code_phase_step_chips,
int signal_length_samples)
{
update_local_code(rem_code_phase_chips);
d_rem_carrier_phase_in_rad = rem_carrier_phase_in_rad;
d_code_phase_step_chips = code_phase_step_chips;
d_phase_step_rad = phase_step_rad;
d_correlator_length_samples = signal_length_samples;
fpga_multicorrelator_8sc::fpga_compute_signal_parameters_in_fpga();
fpga_multicorrelator_8sc::fpga_configure_signal_parameters_in_fpga();
fpga_multicorrelator_8sc::fpga_launch_multicorrelator_fpga();
int irq_count;
ssize_t nb;
// wait for interrupt
nb = read(d_device_descriptor, &irq_count, sizeof(irq_count));
if (nb != sizeof(irq_count))
{
printf("Tracking_module Read failed to retrive 4 bytes!\n");
printf("Tracking_module Interrupt number %d\n", irq_count);
}
fpga_multicorrelator_8sc::read_tracking_gps_results();
return true;
}
fpga_multicorrelator_8sc::fpga_multicorrelator_8sc(int n_correlators,
std::string device_name, unsigned int device_base)
{
d_n_correlators = n_correlators;
d_device_name = device_name;
d_device_base = device_base;
d_device_descriptor = 0;
d_map_base = nullptr;
// instantiate variable length vectors
d_initial_index = static_cast<unsigned*>(volk_gnsssdr_malloc(
n_correlators * sizeof(unsigned), volk_gnsssdr_get_alignment()));
d_initial_interp_counter = static_cast<unsigned*>(volk_gnsssdr_malloc(
n_correlators * sizeof(unsigned), volk_gnsssdr_get_alignment()));
d_local_code_in = nullptr;
d_shifts_chips = nullptr;
d_corr_out = nullptr;
d_code_length_chips = 0;
d_rem_code_phase_chips = 0;
d_code_phase_step_chips = 0;
d_rem_carrier_phase_in_rad = 0;
d_phase_step_rad = 0;
d_rem_carr_phase_rad_int = 0;
d_phase_step_rad_int = 0;
d_initial_sample_counter = 0;
d_channel = 0;
d_correlator_length_samples = 0;
}
fpga_multicorrelator_8sc::~fpga_multicorrelator_8sc()
{
close(d_device_descriptor);
}
bool fpga_multicorrelator_8sc::free()
{
// unlock the hardware
fpga_multicorrelator_8sc::unlock_channel(); // unlock the channel
// free the FPGA dynamically created variables
if (d_initial_index != nullptr)
{
volk_gnsssdr_free(d_initial_index);
d_initial_index = nullptr;
}
if (d_initial_interp_counter != nullptr)
{
volk_gnsssdr_free(d_initial_interp_counter);
d_initial_interp_counter = nullptr;
}
return true;
}
void fpga_multicorrelator_8sc::set_channel(unsigned int channel)
{
char device_io_name[MAX_LENGTH_DEVICEIO_NAME]; // driver io name
d_channel = channel;
// open the device corresponding to the assigned channel
std::string mergedname;
std::stringstream devicebasetemp;
int numdevice = d_device_base + d_channel;
devicebasetemp << numdevice;
mergedname = d_device_name + devicebasetemp.str();
strcpy(device_io_name, mergedname.c_str());
printf("Opening Device Name : %s\n", device_io_name);
if ((d_device_descriptor = open(device_io_name, O_RDWR | O_SYNC)) == -1)
{
LOG(WARNING) << "Cannot open deviceio" << device_io_name;
}
d_map_base = reinterpret_cast<volatile unsigned*>(mmap(NULL, PAGE_SIZE,
PROT_READ | PROT_WRITE, MAP_SHARED, d_device_descriptor, 0));
if (d_map_base == reinterpret_cast<void*>(-1))
{
LOG(WARNING) << "Cannot map the FPGA tracking module "
<< d_channel << "into user memory";
}
// sanity check : check test register
unsigned writeval = TEST_REGISTER_TRACK_WRITEVAL;
unsigned readval;
readval = fpga_multicorrelator_8sc::fpga_acquisition_test_register(writeval);
if (writeval != readval)
{
LOG(WARNING) << "Test register sanity check failed";
}
else
{
LOG(INFO) << "Test register sanity check success !";
}
}
unsigned fpga_multicorrelator_8sc::fpga_acquisition_test_register(
unsigned writeval)
{
unsigned readval;
// write value to test register
d_map_base[15] = writeval;
// read value from test register
readval = d_map_base[15];
// return read value
return readval;
}
void fpga_multicorrelator_8sc::fpga_configure_tracking_gps_local_code(void)
{
int k, s;
unsigned code_chip;
unsigned select_fpga_correlator;
select_fpga_correlator = 0;
for (s = 0; s < d_n_correlators; s++)
{
d_map_base[11] = LOCAL_CODE_FPGA_CLEAR_ADDRESS_COUNTER;
for (k = 0; k < d_code_length_chips; k++)
{
if (lv_creal(d_local_code_in[k]) == 1)
{
code_chip = 1;
}
else
{
code_chip = 0;
}
// copy the local code to the FPGA memory one by one
d_map_base[11] = LOCAL_CODE_FPGA_ENABLE_WRITE_MEMORY | code_chip | select_fpga_correlator;
}
select_fpga_correlator = select_fpga_correlator + LOCAL_CODE_FPGA_CORRELATOR_SELECT_COUNT;
}
}
void fpga_multicorrelator_8sc::fpga_compute_code_shift_parameters(void)
{
float temp_calculation;
int i;
for (i = 0; i < d_n_correlators; i++)
{
// initial index calculation
temp_calculation = floor(
d_shifts_chips[i] + d_rem_code_phase_chips);
if (temp_calculation < 0)
{
temp_calculation = temp_calculation + d_code_length_chips; // % operator does not work as in Matlab with negative numbers
}
d_initial_index[i] = static_cast<unsigned>((static_cast<int>(temp_calculation)) % d_code_length_chips);
// initial interpolator counter calculation
temp_calculation = fmod(d_shifts_chips[i] + d_rem_code_phase_chips,
1.0);
if (temp_calculation < 0)
{
temp_calculation = temp_calculation + 1.0; // fmod operator does not work as in Matlab with negative numbers
}
d_initial_interp_counter[i] = static_cast<unsigned>(floor(MAX_CODE_RESAMPLER_COUNTER * temp_calculation));
}
}
void fpga_multicorrelator_8sc::fpga_configure_code_parameters_in_fpga(void)
{
int i;
for (i = 0; i < d_n_correlators; i++)
{
d_map_base[1 + i] = d_initial_index[i];
d_map_base[1 + d_n_correlators + i] = d_initial_interp_counter[i];
}
d_map_base[8] = d_code_length_chips - 1; // number of samples - 1
}
void fpga_multicorrelator_8sc::fpga_compute_signal_parameters_in_fpga(void)
{
float d_rem_carrier_phase_in_rad_temp;
d_code_phase_step_chips_num = static_cast<unsigned>(roundf(MAX_CODE_RESAMPLER_COUNTER * d_code_phase_step_chips));
if (d_rem_carrier_phase_in_rad > M_PI)
{
d_rem_carrier_phase_in_rad_temp = -2 * M_PI + d_rem_carrier_phase_in_rad;
}
else if (d_rem_carrier_phase_in_rad < -M_PI)
{
d_rem_carrier_phase_in_rad_temp = 2 * M_PI + d_rem_carrier_phase_in_rad;
}
else
{
d_rem_carrier_phase_in_rad_temp = d_rem_carrier_phase_in_rad;
}
d_rem_carr_phase_rad_int = static_cast<int>(roundf(
(fabs(d_rem_carrier_phase_in_rad_temp) / M_PI) * pow(2, PHASE_CARR_NBITS_FRAC)));
if (d_rem_carrier_phase_in_rad_temp < 0)
{
d_rem_carr_phase_rad_int = -d_rem_carr_phase_rad_int;
}
d_phase_step_rad_int = static_cast<int>(roundf(
(fabs(d_phase_step_rad) / M_PI) * pow(2, PHASE_CARR_NBITS_FRAC))); // the FPGA accepts a range for the phase step between -pi and +pi
if (d_phase_step_rad < 0)
{
d_phase_step_rad_int = -d_phase_step_rad_int;
}
}
void fpga_multicorrelator_8sc::fpga_configure_signal_parameters_in_fpga(void)
{
d_map_base[0] = d_code_phase_step_chips_num;
d_map_base[7] = d_correlator_length_samples - 1;
d_map_base[9] = d_rem_carr_phase_rad_int;
d_map_base[10] = d_phase_step_rad_int;
d_map_base[13] = d_initial_sample_counter;
}
void fpga_multicorrelator_8sc::fpga_launch_multicorrelator_fpga(void)
{
// enable interrupts
int reenable = 1;
write(d_device_descriptor, reinterpret_cast<void*>(&reenable), sizeof(int));
d_map_base[14] = 0; // writing anything to reg 14 launches the tracking
}
void fpga_multicorrelator_8sc::read_tracking_gps_results(void)
{
int readval_real;
int readval_imag;
int k;
for (k = 0; k < d_n_correlators; k++)
{
readval_real = d_map_base[1 + k];
if (readval_real >= 1048576) // 0x100000 (21 bits two's complement)
{
readval_real = -2097152 + readval_real;
}
readval_real = readval_real * 2; // the results are shifted two bits to the left due to the complex multiplier in the FPGA
readval_imag = d_map_base[1 + d_n_correlators + k];
if (readval_imag >= 1048576) // 0x100000 (21 bits two's complement)
{
readval_imag = -2097152 + readval_imag;
}
readval_imag = readval_imag * 2; // the results are shifted two bits to the left due to the complex multiplier in the FPGA
d_corr_out[k] = lv_cmake(readval_real, readval_imag);
}
}
void fpga_multicorrelator_8sc::unlock_channel(void)
{
// unlock the channel to let the next samples go through
d_map_base[12] = 1; // unlock the channel
}
void fpga_multicorrelator_8sc::lock_channel(void)
{
// lock the channel for processing
d_map_base[12] = 0; // lock the channel
}