dsplib::ChannelSynthesizer Class Reference

Polyphase FFT synthesis filter bank. More...

#include <subband.h>

Public Member Functions
	ChannelSynthesizer (const ChannelSynthesizer &)=delete
	ChannelSynthesizer (span_real filter, int num_bands, int decim_factor)
	Construct ChannelSynthesizer.
	ChannelSynthesizer (std::shared_ptr< const arr_real > filter, int num_bands, int decim_factor)
	Construct ChannelSynthesizer.
	ChannelSynthesizer (int num_bands, int decim_factor, int num_taps)
	Construct ChannelSynthesizer.
arr_real	process (span_cmplx x)
	Filter bank processing (synthesis)
arr_real	operator() (span_cmplx x)
int	frame_len () const noexcept
	Processing frame size.

Detailed Description

Polyphase FFT synthesis filter bank.

Ideally ChannelSynthesizer(Channelizer(x)) == x.

See also

Matlab dsp.ChannelSynthesizer

Warning

This implementation differs from matlab in the decimation parameter. For decim_factor=1, the results should be identical.

Todo:

remove num_taps if filter is calculated

params order (bands, decim, ntaps/coeffs)

Constructor & Destructor Documentation

ChannelSynthesizer() [1/3]

dsplib::ChannelSynthesizer::ChannelSynthesizer ( span_real  filter, int  num_bands, int  decim_factor  )

explicit

Construct ChannelSynthesizer.

Parameters

filter	Multirate FIR coeffs [num_bands * ntaps]
num_bands	Number of frequency bands
decim_factor	Decimation factor [1 : M-1]

ChannelSynthesizer() [2/3]

dsplib::ChannelSynthesizer::ChannelSynthesizer ( std::shared_ptr< const arr_real >  filter, int  num_bands, int  decim_factor  )

explicit

Construct ChannelSynthesizer.

Use this function to save memory if multiple Channelizer/ChannelSynthesizer objects can exist at the same time

Parameters

filter	Pointer to multirate FIR coeffs
num_bands	Number of frequency bands
decim_factor	Decimation factor [1 : M-1]

ChannelSynthesizer() [3/3]

dsplib::ChannelSynthesizer::ChannelSynthesizer ( int  num_bands, int  decim_factor, int  num_taps  )

explicit

Construct ChannelSynthesizer.

The filter will be calculated using the design_multirate_fir(1, num_bands, ceil(num_taps / 2.0))

Parameters

num_bands	Number of frequency bands
decim_factor	Decimation factor [1 : M-1]
num_taps	Number of filter coefficients per frequency band (expected to be even)

Member Function Documentation

frame_len()

int dsplib::ChannelSynthesizer::frame_len ( ) const

noexcept

Processing frame size.

Returns

int frame len

process()

arr_real dsplib::ChannelSynthesizer::process

(

span_cmplx

x

)

Filter bank processing (synthesis)

Parameters

x	Input subband signal [num_bands]

Returns

arr_cmplx Restored broadband signal [num_bands / decim_factor]

---

The documentation for this class was generated from the following file:

• /home/runner/work/dsplib/dsplib/include/dsplib/subband.h