/* 
 * File:   demodulator.h
 */

#ifndef DEMODULATOR_H
#define	DEMODULATOR_H

#ifdef __XC16
#include <dsp.h>
#else
typedef int16_t _Q0_15;
typedef int32_t _Q15_16;

typedef _Q0_15 _Q15;
typedef _Q15_16 _Q16;

typedef int16_t fractional;
#endif

#include <stdint.h>
#include "modem_types.h"

#define MAX_PHASE_SKEW                  10000L
#define ADC_MAX_AMPLITUDE               10000L

typedef struct {
    fractional frequency;
    fractional phase;
    fractional amplitude;
} detector_symbol;

extern detector_symbol detector_constellation[MAX_MODULATION_ALPHABET_SIZE], symbol_error, min_symbol_distance;

// TODO 

typedef struct {
    uint8_t buffer[MAX_SYMBOL_BUFFER_SIZE];
    uint8_t index;
    uint8_t length;
} symbol_buffer;

// extern symbol_buffer rx_symbol_buffer;

// buffer dei simboli
extern uint8_t rx_symbol_buffer[MAX_SYMBOL_BUFFER_SIZE];
extern uint8_t rx_symbol_buffer_index, rx_symbol_buffer_lenght;

extern uint8_t rx_sample_buffers_buffer[MAX_BUFFERS_PER_SYMBOL], rx_sample_buffer_index;

extern uint8_t volatile process_input_sample_buffer;

// zona del simbolo da esaminare:
extern uint8_t rx_symbol_detected_part_offset, rx_symbol_detected_part_length;

// NCO
extern fractional tanlock_nco_rotor_inc;

#ifdef __DSP_LIB__
extern FIRStruct ph_det_lpFilterI, ph_det_lpFilterQ, ph_det_lpFilterFreq;
#endif

void demodulator_setup(void);
void demodulator_sample_buffer_demodulate(fractional *buffer, detector_symbol* outsymbol);

symbol find_constellation_center_values(symbol *constellation);
int16_t get_angular_frequency(uint16_t frequency);
void demodulator_prepare_constellation_symbols(symbol *constellation, detector_symbol *demod_constellation);
detector_symbol demodulator_find_min_symbol_distance(detector_symbol *demod_constellation);
uint8_t demodulator_most_frequent_value(uint8_t *serie, uint8_t range, uint8_t len);
uint8_t demodulator_find_nearest_symbol(detector_symbol *in_symbol, detector_symbol *target_constellation, detector_symbol *moderror);

fractional demodulator_phase_detector(fractional sig_in);
fractional demodulator_frequency_detector(fractional phase);

fractional _Q15atan2circle(fractional Y, fractional X);
void FIR_init(void);


#endif	/* DEMODULATOR_H */