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Added bpsk_costas_loop_cc base

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ha7ilm 2017-03-14 09:12:09 +01:00
parent eaea93c1e2
commit 2d5c27d3dc
2 changed files with 36 additions and 1 deletions
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2
csdr.c
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@ -2376,7 +2376,7 @@ int main(int argc, char *argv[])
timing_recovery_state_t state = timing_recovery_init(algorithm, decimation, add_q);
int debug_i=0;
state.debug_writefiles = 0;
state.debug_writefiles = 1;
state.debug_force = !!debug_n; //should remove that later
FREAD_C;
for(;;)

35
libcsdr.c
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@ -1820,6 +1820,41 @@ char* timing_recovery_get_string_from_algorithm(timing_recovery_algorithm_t algo
return "INVALID";
}
typedef struct bpsk_costas_loop_state_s
{
float pll_alpha;
float pll_beta;
float pll_iir_temp;
float pll_phase;
} bpsk_costas_loop_state_t;
void init_bpsk_carrier_recovery_cc(bpsk_costas_loop_state_t* state)
{
state->pll_alpha = state->pll_beta = 0; //TODO <--
state->pll_phase = 0;
state->pll_iir_temp = 0;
}
void bpsk_costas_loop_cc(complexf* input, complexf* output, int input_size, bpsk_costas_loop_state_t* state)
{
complexf ejphi; //downconvert with that
for(int i=0;i<input_size;i++)
{
e_powj(&ejphi, -state->pll_phase);
cmult(&output[i], &input[i], &ejphi);
float error = iof(output,i) * qof(output, i);
if(error>2) error=2;
if(error<-2) error=-2;
state->pll_phase = error * state->pll_alpha + state->pll_iir_temp;
state->pll_iir_temp += error * state->pll_beta;
while(state->pll_phase>PI) state->pll_phase-=2*PI;
while(state->pll_phase<-PI) state->pll_phase+=2*PI;
}
}
/*
_____ _ _