SNR Estimator using 2nd and 4th-order moments. More...

#include <gnuradio/digital/mpsk_snr_est.h>

Public Member Functions
	mpsk_snr_est_m2m4 (double alpha)

	~mpsk_snr_est_m2m4 () override

int	update (int noutput_items, const gr_complex *input) override
	Update the current registers. More...

double	snr () override
	Use the register values to compute a new estimate. More...

Public Member Functions inherited from gr::digital::mpsk_snr_est
	mpsk_snr_est (double alpha)

virtual	~mpsk_snr_est ()

double	alpha () const
	Get the running-average coefficient. More...

void	set_alpha (double alpha)
	Set the running-average coefficient. More...

virtual double	signal ()
	Returns the signal power estimate. More...

virtual double	noise ()
	Returns the noise power estimate. More...

Additional Inherited Members
Protected Attributes inherited from gr::digital::mpsk_snr_est
double	d_alpha

double	d_beta

double	d_signal

double	d_noise

Detailed Description

SNR Estimator using 2nd and 4th-order moments.

An SNR estimator for M-PSK signals that uses 2nd (M2) and 4th (M4) order moments. This estimator uses knowledge of the kurtosis of the signal ( $k_a)$ and noise ( $k_w$ ) to make its estimation. We use Beaulieu's approximations here to M-PSK signals and AWGN channels such that $k_a=1$ and $k_w=2$ . These approximations significantly reduce the complexity of the calculations (and computations) required.

Reference: D. R. Pauluzzi and N. C. Beaulieu, "A comparison of SNR estimation techniques for the AWGN channel," IEEE Trans. Communications, Vol. 48, No. 10, pp. 1681-1691, 2000.

Constructor & Destructor Documentation

◆ mpsk_snr_est_m2m4()

gr::digital::mpsk_snr_est_m2m4::mpsk_snr_est_m2m4 ( double alpha )

Constructor

Parameters:

Parameters

alpha the update rate of internal running average calculations.

◆ ~mpsk_snr_est_m2m4()

gr::digital::mpsk_snr_est_m2m4::~mpsk_snr_est_m2m4 ( )

inlineoverride

Member Function Documentation

◆ snr()

double gr::digital::mpsk_snr_est_m2m4::snr ( )

overridevirtual

Use the register values to compute a new estimate.

Reimplemented from gr::digital::mpsk_snr_est.

◆ update()

int gr::digital::mpsk_snr_est_m2m4::update	(	int	noutput_items,
		const gr_complex *	input
	)

overridevirtual

Update the current registers.