File filtering.hpp

class Filtering
#include <filtering.hpp>

Class for filtering.

Public Functions

Filtering() = default
explicit Filtering(std::vector<std::vector<float>> input_filter_taps)

The constructor finds the number of filter taps for each stage and then a lowpass filter for each stage.


input_filter_taps[in] The filter taps sent from radar control.

void save_filter_to_file(const std::vector<std::complex<float>> &filter_taps, std::string name)

Writes out a set of filter taps to file in case they need to be tested.

  • filter_taps[in] A reference to a vector of filter taps.

  • name[in] A output file name.

void mix_first_stage_to_bandpass(const std::vector<double> &rx_freqs, double initial_rx_rate)

Mixes the first stage lowpass filter to bandpass filters for each RX frequency.

Creates a flatbuffer with a bandpass filter for each RX frequency to be used in decimation.

  • rx_freqs[in] rx_freqs A reference to a vector of RX frequencies in Hz.

  • initial_rx_sample_rate[in] initial_rx_sample_rate The USRP RX sampling rate in Hz.

std::vector<std::vector<std::complex<float>>> get_mixed_filter_taps()

Gets the mixed filter taps at each stage.

A temp vector is created. The first stage taps are replaced with the bandpass taps.


The mixed filter taps.

std::vector<std::vector<std::complex<float>>> get_unmixed_filter_taps()

Gets the unmixed filter taps at each stage.

The unmixed filter taps are returned.


The unmixed filter taps.

Private Functions

std::vector<std::complex<float>> fill_filter(std::vector<float> &filter_taps)

Fills the lowpass filter taps with zero to a size that is a power of 2.


filter_taps[in] The filter taps provided, will be real.


A vector of filter taps. Filter is real, but represented using complex<float> form R + i0 for each tap. The vector is filled with zeros at the end to reach a length that is a power of 2 for processing.

Private Members

std::vector<std::vector<std::complex<float>>> filter_taps

Vector that holds the vectors of filter taps at each stage.

std::vector<std::complex<float>> bandpass_taps

A vector to hold the bandpass taps after first stage filter has been mixed.