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Simplify PhaseEstimator.

pull/3/head
Rob Riggs 2020-11-30 18:58:16 -06:00
rodzic 091e423d98
commit b4c99648b9
1 zmienionych plików z 9 dodań i 24 usunięć
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33
PhaseEstimator.h
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@ -17,22 +17,17 @@ namespace mobilinkd
* these errors have not affected the performance of clock
* recovery.
*/
template <typename T>
template <typename FloatType>
struct PhaseEstimator
{
using float_type = T;
using samples_t = std::array<float_type, 3>; // 3 samples in length
using minmax_t = std::array<float_type, 32>; // 32 symbols in length
using float_type = FloatType;
using samples_t = std::array<FloatType, 3>; // 3 samples in length
float_type dx_;
minmax_t symbols_{0};
size_t index_ = 0;
PhaseEstimator(float_type sample_rate, float_type symbol_rate)
PhaseEstimator(FloatType sample_rate, FloatType symbol_rate)
: dx_(2.0 * symbol_rate / sample_rate)
{
symbols_.fill(0.0);
}
{}
/**
* This performs a rolling estimate of the phase.
@ -43,21 +38,11 @@ struct PhaseEstimator
float_type operator()(const samples_t& samples)
{
assert(dx_ > 0.0);
symbols_[index_++] = samples[1];
if (index_ == std::tuple_size<minmax_t>::value) index_ = 0;
auto symbol_min = *std::min_element(std::begin(symbols_), std::end(symbols_));
auto symbol_max = *std::max_element(std::begin(symbols_), std::end(symbols_));
auto y_scale = (symbol_max - symbol_min) * 0.5;
auto dy = y_scale != 0 ? (samples.at(2) - samples.at(0)) / y_scale : 0;
auto ratio = dy / dx_;
auto ratio = ((samples.at(2) - samples.at(0)) / 3) / dx_;
// Clamp +/-5.
ratio = std::min(float_type(5.0), ratio);
ratio = std::max(float_type(-5.0), ratio);
ratio = std::min(FloatType(5.0), ratio);
ratio = std::max(FloatType(-5.0), ratio);
return ratio;
}