Untemplate MatchedFilter, a different way.

This commit is contained in:
Jared Boone 2015-10-14 17:20:27 -07:00
parent fe94cfa45a
commit 4141d6fe0f
3 changed files with 43 additions and 26 deletions

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@ -24,5 +24,24 @@
namespace dsp { namespace dsp {
namespace matched_filter { namespace matched_filter {
bool MatchedFilter::execute_once(
const sample_t input
) {
samples_[taps_count_ - decimation_factor + decimation_phase] = input;
advance_decimation_phase();
if( is_new_decimation_cycle() ) {
output = std::inner_product(&samples_[0], &samples_[taps_count_], &taps_[0], sample_t { 0.0f, 0.0f });
shift_by_decimation_factor();
return true;
} else {
return false;
}
}
void MatchedFilter::shift_by_decimation_factor() {
std::rotate(&samples_[0], &samples_[decimation_factor], &samples_[taps_count_]);
}
} /* namespace matched_filter */ } /* namespace matched_filter */
} /* namespace dsp */ } /* namespace dsp */

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@ -23,6 +23,7 @@
#define __MATCHED_FILTER_H__ #define __MATCHED_FILTER_H__
#include "baseband_ais.hpp" #include "baseband_ais.hpp"
#include "utility.hpp"
#include <cstddef> #include <cstddef>
@ -36,53 +37,50 @@
namespace dsp { namespace dsp {
namespace matched_filter { namespace matched_filter {
template<size_t N>
class MatchedFilter { class MatchedFilter {
public: public:
using sample_t = std::complex<float>; using sample_t = std::complex<float>;
using tap_t = std::complex<float>; using tap_t = std::complex<float>;
using taps_t = std::array<tap_t, N>; using taps_t = tap_t[];
MatchedFilter( MatchedFilter(
const taps_t& taps, const tap_t* const taps,
const size_t taps_count,
size_t decimation_factor = 1 size_t decimation_factor = 1
) : taps(taps), ) : samples_ { std::make_unique<samples_t>(taps_count) },
taps_ { std::make_unique<taps_t>(taps_count) },
taps_count_ { taps_count },
decimation_factor { decimation_factor } decimation_factor { decimation_factor }
{
std::copy(&taps[0], &taps[taps_count], &taps_[0]);
}
template<typename T>
MatchedFilter(
const T& taps,
size_t decimation_factor = 1
) : MatchedFilter(taps.data(), taps.size(), decimation_factor)
{ {
} }
bool execute_once( bool execute_once(const sample_t input);
const sample_t input
) {
samples[samples.size() - decimation_factor + decimation_phase] = input;
advance_decimation_phase();
if( is_new_decimation_cycle() ) {
output = std::inner_product(samples.cbegin(), samples.cend(), taps.cbegin(), sample_t { 0.0f, 0.0f });
shift_by_decimation_factor();
return true;
} else {
return false;
}
}
sample_t get_output() const { sample_t get_output() const {
return output; return output;
} }
private: private:
using samples_t = std::array<sample_t, N>; using samples_t = sample_t[];
samples_t samples; const std::unique_ptr<samples_t> samples_;
const taps_t taps; const std::unique_ptr<taps_t> taps_;
const size_t taps_count_;
size_t decimation_factor { 1 }; size_t decimation_factor { 1 };
size_t decimation_phase { 0 }; size_t decimation_phase { 0 };
sample_t output; sample_t output;
void shift_by_decimation_factor() { void shift_by_decimation_factor();
std::rotate(samples.begin(), samples.begin() + decimation_factor, samples.end());
}
void advance_decimation_phase() { void advance_decimation_phase() {
decimation_phase = (decimation_phase + 1) % decimation_factor; decimation_phase = (decimation_phase + 1) % decimation_factor;

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@ -57,8 +57,8 @@ private:
const fir_taps_real<64>& channel_filter_taps = taps_64_lp_031_070_tfilter; const fir_taps_real<64>& channel_filter_taps = taps_64_lp_031_070_tfilter;
dsp::decimate::FIRAndDecimateBy2Complex<64> channel_filter { channel_filter_taps.taps }; dsp::decimate::FIRAndDecimateBy2Complex<64> channel_filter { channel_filter_taps.taps };
dsp::matched_filter::MatchedFilter<8> mf_0 { baseband::ais::rrc_taps_8_n, 1 }; dsp::matched_filter::MatchedFilter mf_0 { baseband::ais::rrc_taps_8_n, 1 };
dsp::matched_filter::MatchedFilter<8> mf_1 { baseband::ais::rrc_taps_8_p, 1 }; dsp::matched_filter::MatchedFilter mf_1 { baseband::ais::rrc_taps_8_p, 1 };
clock_recovery::ClockRecovery<clock_recovery::FixedErrorFilter> clock_recovery { clock_recovery::ClockRecovery<clock_recovery::FixedErrorFilter> clock_recovery {
static_cast<float>(sampling_rate / 4), static_cast<float>(sampling_rate / 4),