FSK demodulator: Also report bits that have duration < 0.5
This commit is contained in:
parent
445af0c0a2
commit
830794bae4
|
@ -324,6 +324,18 @@ void fsk_demod_receive(fsk_demod_t *fsk, sample_t *sample, int length)
|
|||
if (fsk->rx_bitpos < 0.5)
|
||||
fsk->rx_bitpos = 0.5;
|
||||
}
|
||||
/* if we have a pulse before we sampled a bit after last pulse */
|
||||
if (fsk->rx_change) {
|
||||
/* peak level is the length of I/Q vector
|
||||
* since we filter out the unwanted modulation product, the vector is only half of length */
|
||||
level = sqrt(I[i] * I[i] + Q[i] * Q[i]) * 2.0;
|
||||
#ifdef DEBUG_FILTER
|
||||
printf("prematurely bit change (level=%.3f)\n", level / fsk->level);
|
||||
#endif
|
||||
/* quality is 0.0, because a prematurely level change is caused by noise and has nothing to measure. */
|
||||
fsk->receive_bit(fsk->inst, fsk->rx_bit, 0.0, level);
|
||||
}
|
||||
fsk->rx_change = 1;
|
||||
}
|
||||
/* if bit counter reaches 1, we subtract 1 and sample the bit */
|
||||
if (fsk->rx_bitpos >= 1.0) {
|
||||
|
@ -344,6 +356,7 @@ void fsk_demod_receive(fsk_demod_t *fsk, sample_t *sample, int length)
|
|||
/* adjust the values, because this is best we can get from fm demodulator */
|
||||
fsk->receive_bit(fsk->inst, bit, quality / 0.95, level);
|
||||
fsk->rx_bitpos -= 1.0;
|
||||
fsk->rx_change = 0;
|
||||
}
|
||||
fsk->rx_bitpos += fsk->bits_per_sample;
|
||||
}
|
||||
|
|
|
@ -30,6 +30,7 @@ typedef struct fsk_demod {
|
|||
int rx_bit; /* current receiving bit (-1 if not yet measured) */
|
||||
double rx_bitpos; /* current receive position in bit (sampleclock) */
|
||||
double rx_bitadjust; /* how much does a bit change cause the sample clock to be adjusted in phase */
|
||||
int rx_change; /* set, if we have a level change before sampling the bit */
|
||||
} fsk_demod_t;
|
||||
|
||||
int fsk_mod_init(fsk_mod_t *fsk, void *inst, int (*send_bit)(void *inst), int samplerate, double bitrate, double f0, double f1, double level, int coherent, int filter);
|
||||
|
|
Loading…
Reference in New Issue