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Improved Notch Filter Lite

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Updated version of the filter
This commit is contained in:
Antonio Ramos 2017-08-22 13:21:28 +02:00
parent 630ec1e77b
commit 3536bce55c
6 changed files with 142 additions and 32 deletions
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8
src/algorithms/input_filter/adapters/notch_filter.cc
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@ -53,6 +53,10 @@ NotchFilter::NotchFilter(ConfigurationInterface* configuration, std::string role
float default_p_c_factor = 0.9;
int length_;
int default_length_ = 32;
int n_segments_est;
int default_n_segments_est = 12500;
int n_segments_reset;
int default_n_segments_reset = 5000000;
std::string default_item_type = "gr_complex";
std::string default_dump_file = "./data/input_filter.dat";
item_type_ = configuration->property(role + ".item_type", default_item_type);
@ -62,10 +66,12 @@ NotchFilter::NotchFilter(ConfigurationInterface* configuration, std::string role
pfa = configuration->property(role + ".pfa", default_pfa);
p_c_factor = configuration->property(role + ".p_c_factor", default_p_c_factor);
length_ = configuration->property(role + ".length", default_length_);
n_segments_est = configuration->property(role + ".segments_est", default_n_segments_est);
n_segments_reset = configuration->property(role + ".segments_reset", default_n_segments_reset);
if (item_type_.compare("gr_complex") == 0)
{
item_size_ = sizeof(gr_complex);
notch_filter_ = make_notch_filter(pfa, p_c_factor, length_);
notch_filter_ = make_notch_filter(pfa, p_c_factor, length_, n_segments_est, n_segments_reset);
DLOG(INFO) << "Item size " << item_size_;
DLOG(INFO) << "input filter(" << notch_filter_->unique_id() << ")";

23
src/algorithms/input_filter/adapters/notch_filter_lite.cc
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@ -31,6 +31,7 @@
#include "notch_filter_lite.h"
#include <string>
#include <cmath>
#include <memory>
#include <vector>
#include <boost/lexical_cast.hpp>
@ -49,6 +50,18 @@ NotchFilterLite::NotchFilterLite(ConfigurationInterface* configuration, std::str
size_t item_size_;
float p_c_factor;
float default_p_c_factor = 0.9;
float pfa;
float default_pfa = 0.001;
int length_;
int default_length_ = 32;
int n_segments_est;
int default_n_segments_est = 12500;
int n_segments_reset;
int default_n_segments_reset = 5000000;
float default_samp_freq = 4000000;
float samp_freq = configuration->property("SignalSource.sampling_frequency", default_samp_freq);
float default_coeff_rate = samp_freq * 0.1;
float coeff_rate;
std::string default_item_type = "gr_complex";
std::string default_dump_file = "./data/input_filter.dat";
item_type_ = configuration->property(role + ".item_type", default_item_type);
@ -56,13 +69,19 @@ NotchFilterLite::NotchFilterLite(ConfigurationInterface* configuration, std::str
DLOG(INFO) << "dump_ is " << dump_;
dump_filename_ = configuration->property(role + ".dump_filename", default_dump_file);
p_c_factor = configuration->property(role + ".p_c_factor", default_p_c_factor);
pfa = configuration->property(role + ".pfa", default_pfa);
coeff_rate = configuration->property(role + ".coeff_rate", default_coeff_rate);
length_ = configuration->property(role + ".length", default_length_);
n_segments_est = configuration->property(role + ".segments_est", default_n_segments_est);
n_segments_reset = configuration->property(role + ".segments_reset", default_n_segments_reset);
int n_segments_coeff = (int) ((samp_freq / coeff_rate) / ((float) length_));
n_segments_coeff = std::max(1, n_segments_coeff);
if (item_type_.compare("gr_complex") == 0)
{
item_size_ = sizeof(gr_complex);
notch_filter_lite_ = make_notch_filter_lite(p_c_factor);
notch_filter_lite_ = make_notch_filter_lite(p_c_factor, pfa, length_, n_segments_est, n_segments_reset, n_segments_coeff);
DLOG(INFO) << "Item size " << item_size_;
DLOG(INFO) << "input filter(" << notch_filter_lite_->unique_id() << ")";
}
else
{

10
src/algorithms/input_filter/gnuradio_blocks/notch_cc.cc
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@ -43,12 +43,12 @@
using google::LogMessage;
notch_sptr make_notch_filter(float pfa, float p_c_factor,
int length_)
int length_, int n_segments_est, int n_segments_reset)
{
return notch_sptr(new Notch(pfa, p_c_factor, length_));
return notch_sptr(new Notch(pfa, p_c_factor, length_, n_segments_est, n_segments_reset));
}
Notch::Notch(float pfa, float p_c_factor, int length_) : gr::block("Notch",
Notch::Notch(float pfa, float p_c_factor, int length_, int n_segments_est, int n_segments_reset) : gr::block("Notch",
gr::io_signature::make (1, 1, sizeof(gr_complex)),
gr::io_signature::make (1, 1, sizeof(gr_complex)))
{
@ -63,8 +63,8 @@ Notch::Notch(float pfa, float p_c_factor, int length_) : gr::block("Notch",
filter_state_ = false; //Initial state of the filter
n_deg_fred = 2 * length_; //Number of dregrees of freedom
n_segments = 0;
n_segments_est = 8; // Set the number of segments for noise power estimation
n_segments_reset = 10000; // Set the period (in segments) when the noise power is estimated
this->n_segments_est = n_segments_est; // Set the number of segments for noise power estimation
this->n_segments_reset = n_segments_reset; // Set the period (in segments) when the noise power is estimated
z_0 = gr_complex(0 , 0);
boost::math::chi_squared_distribution<float> my_dist_(n_deg_fred);
thres_ = boost::math::quantile(boost::math::complement(my_dist_, pfa));

4
src/algorithms/input_filter/gnuradio_blocks/notch_cc.h
View File

@ -39,7 +39,7 @@ class Notch;
typedef boost::shared_ptr<Notch> notch_sptr;
notch_sptr make_notch_filter(float pfa, float p_c_factor,
int length_);
int length_, int n_segments_est, int n_segments_reset);
/*!
* \brief This class implements a real-time software-defined multi state notch filter
@ -67,7 +67,7 @@ private:
public:
Notch(float pfa, float p_c_factor, int length_);
Notch(float pfa, float p_c_factor, int length_, int n_segments_est, int n_segments_reset);
~Notch();

105
src/algorithms/input_filter/gnuradio_blocks/notch_lite_cc.cc
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@ -37,15 +37,17 @@
#include <volk/volk.h>
#include <iostream>
#include <glog/logging.h>
#include <boost/math/distributions/chi_squared.hpp>
#include <armadillo>
using google::LogMessage;
notch_lite_sptr make_notch_filter_lite(float p_c_factor)
notch_lite_sptr make_notch_filter_lite(float p_c_factor, float pfa, int length_, int n_segments_est, int n_segments_reset, int n_segments_coeff)
{
return notch_lite_sptr(new NotchLite(p_c_factor));
return notch_lite_sptr(new NotchLite(p_c_factor, pfa, length_, n_segments_est, n_segments_reset, n_segments_coeff));
}
NotchLite::NotchLite(float p_c_factor) : gr::block("NotchLite",
NotchLite::NotchLite(float p_c_factor, float pfa, int length_, int n_segments_est, int n_segments_reset, int n_segments_coeff) : gr::block("NotchLite",
gr::io_signature::make (1, 1, sizeof(gr_complex)),
gr::io_signature::make (1, 1, sizeof(gr_complex)))
{
@ -53,28 +55,97 @@ NotchLite::NotchLite(float p_c_factor) : gr::block("NotchLite",
set_alignment(std::max(1, alignment_multiple));
set_history(2);
this->p_c_factor = gr_complex(p_c_factor , 0);
this->n_segments_est = n_segments_est;
this->n_segments_reset = n_segments_reset;
this->n_segments_coeff_reset = n_segments_coeff;
this->n_segments_coeff = 0;
this->length_ = length_;
set_output_multiple(length_);
this->pfa = pfa;
n_segments = 0;
n_deg_fred = 2 * length_;
noise_pow_est = 0.0;
filter_state_ = false;
z_0 = gr_complex(0 , 0);
last_out = gr_complex(0,0);
last_out = gr_complex(0, 0);
boost::math::chi_squared_distribution<float> my_dist_(n_deg_fred);
thres_ = boost::math::quantile(boost::math::complement(my_dist_, pfa));
c_samples = gr_complex(0, 0);
angle_ = 0.0;
power_spect = static_cast<float *>(volk_malloc(length_ * sizeof(float), volk_get_alignment()));
}
NotchLite::~NotchLite()
{
volk_free(power_spect);
}
int NotchLite::general_work(int noutput_items __attribute__((unused)), gr_vector_int &ninput_items __attribute__((unused)),
gr_vector_const_void_star &input_items, gr_vector_void_star &output_items)
{
int index_out = 0;
float sig2dB = 0.0;
float sig2lin = 0.0;
lv_32fc_t dot_prod_;
gr_complex* in = (gr_complex *) input_items[0];
gr_complex* out = (gr_complex *) output_items[0];
c_samples = static_cast<gr_complex *>(volk_malloc(noutput_items * sizeof(gr_complex), volk_get_alignment()));
angle_ = static_cast<float *>(volk_malloc(noutput_items * sizeof(float), volk_get_alignment()));
volk_32fc_x2_multiply_conjugate_32fc(c_samples, (in + 1), in, noutput_items);
volk_32fc_s32f_atan2_32f(angle_, c_samples, ((float)1.0), noutput_items);
for (int aux = 0; aux < noutput_items; aux++)
in++;
arma::cx_fvec signal_segment;
arma::cx_fvec signal_segment_fft;
while((index_out + length_) < noutput_items)
{
z_0 = std::exp(gr_complex(0,1) * (*(angle_ + aux)));
*(out + aux) = *(in + aux + 1) - z_0 * (*(in + aux)) + p_c_factor * z_0 * last_out;
last_out = *(out + aux);
if((n_segments < n_segments_est) && (filter_state_ == false))
{
signal_segment = arma::cx_fvec(in, length_, false, false);
signal_segment_fft = arma::fft(signal_segment);
volk_32fc_s32f_power_spectrum_32f(power_spect, signal_segment_fft.memptr(), 1.0, length_);
volk_32f_s32f_calc_spectral_noise_floor_32f(&sig2dB, power_spect, 15.0, length_);
sig2lin = std::pow(10.0, (sig2dB / 10.0)) / ((float) n_deg_fred);
noise_pow_est = (((float) n_segments) * noise_pow_est + sig2lin) / ((float)(n_segments + 1));
memcpy(out, in, sizeof(gr_complex) * length_);
}
else
{
volk_32fc_x2_conjugate_dot_prod_32fc(&dot_prod_, in, in, length_);
if( (lv_creal(dot_prod_) / noise_pow_est) > thres_)
{
if(filter_state_ == false)
{
filter_state_ = true;
last_out = gr_complex(0,0);
n_segments_coeff = 0;
}
if(n_segments_coeff == 0)
{
volk_32fc_x2_multiply_conjugate_32fc(&c_samples, in, (in - 1), 1);
volk_32fc_s32f_atan2_32f(&angle_, &c_samples, ((float)1.0), 1);
z_0 = std::exp(gr_complex(0,1) * angle_);
}
for(int aux = 0; aux < length_; aux++)
{
*(out + aux) = *(in + aux) - z_0 * (*(in + aux - 1)) + p_c_factor * z_0 * last_out;
last_out = *(out + aux);
}
n_segments_coeff++;
n_segments_coeff = n_segments_coeff % n_segments_coeff_reset;
}
else
{
if (n_segments > n_segments_reset)
{
n_segments = 0;
}
filter_state_ = false;
memcpy(out, in, sizeof(gr_complex) * length_);
}
}
index_out += length_;
n_segments++;
in += length_;
out += length_;
}
volk_free(c_samples);
volk_free(angle_);
consume_each(noutput_items);
return noutput_items;
consume_each(index_out);
return index_out;
}

24
src/algorithms/input_filter/gnuradio_blocks/notch_lite_cc.h
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@ -38,7 +38,7 @@ class NotchLite;
typedef boost::shared_ptr<NotchLite> notch_lite_sptr;
notch_lite_sptr make_notch_filter_lite(float p_c_factor);
notch_lite_sptr make_notch_filter_lite(float p_c_factor, float pfa, int length_, int n_segments_est, int n_segments_reset, int n_segments_coeff);
/*!
* \brief This class implements a real-time software-defined single state notch filter
@ -48,15 +48,29 @@ class NotchLite : public gr::block
{
private:
int length_;
int n_segments;
int n_segments_est;
int n_segments_reset;
int n_segments_coeff_reset;
int n_segments_coeff;
int n_deg_fred;
float pfa;
float thres_;
float noise_pow_est;
bool filter_state_;
gr_complex last_out;
gr_complex z_0;
gr_complex p_c_factor;
gr_complex* c_samples;
float* angle_;
gr_complex c_samples;
float angle_;
float* power_spect;
public:
NotchLite(float p_c_factor);
NotchLite(float p_c_factor, float pfa, int length_, int n_segments_est, int n_segments_reset, int n_segments_coeff);
~NotchLite();
int general_work (int noutput_items, gr_vector_int &ninput_items,
gr_vector_const_void_star &input_items,