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/*---------------------------------------------------------------------------*\
FILE........: cohpsk_internal.h
AUTHOR......: David Rowe
DATE CREATED: March 2015
Functions that implement a coherent PSK FDM modem.
\*---------------------------------------------------------------------------*/
/*
Copyright (C) 2015 David Rowe
All rights reserved.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License version 2.1, as
published by the Free Software Foundation. This program 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 Lesser General Public License
along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#ifndef __COHPSK_INTERNAL__
#define __COHPSK_INTERNAL__
#define NCT_SYMB_BUF (2*NSYMROWPILOT+2)
#define COHPSK_ND 2 /* diversity factor ND 1 is no diveristy, ND we have original plus
one copy */
#define NSW 4 /* number of sync window frames */
#define COHPSK_M 100 /* oversampling rate */
#define COHPSK_NSYM 6
#define COHPSK_NFILTER (COHPSK_NSYM*COHPSK_M)
#define COHPSK_EXCESS_BW 0.5 /* excess BW factor of root nyq filter */
#define COHPSK_NT 5 /* number of symbols we estimate timing over */
#include "fdmdv_internal.h"
#include "kiss_fft.h"
struct COHPSK {
COMP ch_fdm_frame_buf[NSW*NSYMROWPILOT*COHPSK_M]; /* buffer of several frames of symbols from channel */
float pilot2[2*NPILOTSFRAME][COHPSK_NC];
float phi_[NSYMROWPILOT][COHPSK_NC*COHPSK_ND]; /* phase estimates for this frame of rx data symbols */
float amp_[NSYMROW][COHPSK_NC*COHPSK_ND]; /* amplitude estimates for this frame of rx data symbols */
COMP rx_symb[NSYMROWPILOT][COHPSK_NC*COHPSK_ND]; /* demodulated symbols */
float f_est;
COMP rx_filter_memory[COHPSK_NC*COHPSK_ND][COHPSK_NFILTER];
COMP ct_symb_buf[NCT_SYMB_BUF][COHPSK_NC*COHPSK_ND];
int ct; /* coarse timing offset in symbols */
float rx_timing; /* fine timing for last symbol in frame */
int nin; /* number of samples to input for next symbol */
float f_fine_est;
COMP ff_rect;
COMP ff_phase;
COMP ct_symb_ff_buf[NSYMROWPILOT+2][COHPSK_NC*COHPSK_ND];
int sync;
int sync_timer;
int frame;
float ratio;
float sig_rms;
float noise_rms;
struct FDMDV *fdmdv;
int verbose;
int *ptest_bits_coh_tx;
int *ptest_bits_coh_rx[2];
int *ptest_bits_coh_end;
/* counting bit errors using pilots */
int npilotbits;
int npilotbiterrors;
/* optional log variables used for testing Octave to C port */
COMP *rx_baseband_log;
int rx_baseband_log_col_index;
int rx_baseband_log_col_sz;
COMP *rx_filt_log;
int rx_filt_log_col_index;
int rx_filt_log_col_sz;
COMP *ch_symb_log;
int ch_symb_log_r;
int ch_symb_log_col_sz;
float *rx_timing_log;
int rx_timing_log_index;
/* demodulated bits before diversity combination for test/instrumentation purposes */
float rx_bits_lower[COHPSK_BITS_PER_FRAME];
float rx_bits_upper[COHPSK_BITS_PER_FRAME];
/* tx amplitude weights for each carrier for test/instrumentation */
float carrier_ampl[COHPSK_NC*COHPSK_ND];
/* Flag enabling simple freq est mode */
int freq_est_mode_reduced;
};
void bits_to_qpsk_symbols(COMP tx_symb[][COHPSK_NC*COHPSK_ND], int tx_bits[], int nbits);
void qpsk_symbols_to_bits(struct COHPSK *coh, float rx_bits[], COMP ct_symb_buf[][COHPSK_NC*COHPSK_ND]);
void tx_filter_and_upconvert_coh(COMP tx_fdm[], int Nc, const COMP tx_symbols[],
COMP tx_filter_memory[][COHPSK_NSYM],
COMP phase_tx[], COMP freq[],
COMP *fbb_phase, COMP fbb_rect);
void fdm_downconvert_coh(COMP rx_baseband[][COHPSK_M+COHPSK_M/P], int Nc, COMP rx_fdm[], COMP phase_rx[], COMP freq[], int nin);
void frame_sync_fine_freq_est(struct COHPSK *coh, COMP ch_symb[][COHPSK_NC*COHPSK_ND], int sync, int *next_sync);
void fine_freq_correct(struct COHPSK *coh, int sync, int next_sync);
int sync_state_machine(struct COHPSK *coh, int sync, int next_sync);
int cohpsk_fs_offset(COMP out[], COMP in[], int n, float sample_rate_ppm);
#endif
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