44 lines
1.2 KiB
C
44 lines
1.2 KiB
C
#ifndef __DSSS_DEMOD_H__
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#define __DSSS_DEMOD_H__
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#define DSSS_GOLD_CODE_LENGTH ((1<<DSSS_GOLD_CODE_NBITS) - 1)
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#define DSSS_GOLD_CODE_COUNT ((1<<DSSS_GOLD_CODE_NBITS) + 1)
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#define DSSS_CORRELATION_LENGTH (DSSS_GOLD_CODE_LENGTH * DSSS_DECIMATION)
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struct iir_biquad {
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float a[2];
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float b[3];
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};
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struct iir_biquad_state {
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float reg[2];
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};
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struct cwt_iir_filter_state {
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struct iir_biquad_state st[3];
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};
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struct dsss_demod_state {
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float signal[DSSS_CORRELATION_LENGTH];
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size_t signal_wpos;
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float correlation[DSSS_GOLD_CODE_COUNT][DSSS_WAVELET_LUT_SIZE];
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size_t correlation_wpos;
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struct cwt_iir_filter_state cwt_filter[DSSS_GOLD_CODE_COUNT];
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struct {
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int len; /* length of group in samples */
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float max; /* signed value of largest peak in group on any channel */
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int max_idx; /* position of above peak counted from start of group */
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int max_ch; /* channel (gold sequence index) of above peak */
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} group;
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};
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#ifdef SIMULATION
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void dsss_demod_step(struct dsss_demod_state *st, float new_value, size_t sim_pos, int record_channel);
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#else /* SIMULATION */
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void dsss_demod_step(struct dsss_demod_state *st, float new_value);
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#endif /* SIMULATION */
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#endif /* __DSSS_DEMOD_H__ */
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