Y = step(H,X) Y = step(H,X,XT) Y = step(H,X,ANG) Y = step(H,X,XT,ANG) [Y,W] =
step(___)

Description

Y = step(H,X) performs
MVDR beamforming on the input, X, and returns
the beamformed output in Y. This syntax uses X as
the training samples to calculate the beamforming weights.

Y = step(H,X,XT) uses XT as
the training samples to calculate the beamforming weights. This syntax
is available when you set the TrainingInputPort property
to true.

Y = step(H,X,ANG) uses ANG as
the beamforming direction. This syntax is available when you set the DirectionSource property
to 'Input port'.

Y = step(H,X,XT,ANG) combines
all input arguments. This syntax is available when you set the TrainingInputPort property
to true and set the DirectionSource property
to 'Input port'.

[Y,W] =
step(___) returns the beamforming weights, W.
This syntax is available when you set the WeightsOutputPort property
to true.

Note:H specifies the System object™ on which
to run this step method.

The object performs an initialization the first time the step method
is executed. This initialization locks nontunable
properties and input specifications, such as dimensions, complexity,
and data type of the input data. If you change a nontunable property
or an input specification, the System object issues an error.
To change nontunable properties or inputs, you must first call the release method
to unlock the object.

Input Arguments

H

Beamformer object.

X

Input signal, specified as an M-by-N matrix.
If the sensor array contains subarrays, N is the
number of subarrays; otherwise, N is the number
of elements. If you set the TrainingInputPort to false,
M must be larger than N; otherwise, M can
be any positive integer.

XT

Training samples, specified as a P-by-N matrix.
If the sensor array contains subarrays, N is the
number of subarrays; otherwise, N is the number
of elements. P must be larger than N.

ANG

Beamforming directions, specified as a two-row matrix. Each
column has the form [AzimuthAngle; ElevationAngle], in degrees. Each
azimuth angle must be between –180 and 180 degrees, and each
elevation angle must be between –90 and 90 degrees.

Output Arguments

Y

Beamformed output. Y is an M-by-L matrix,
where M is the number of rows of X and L is
the number of beamforming directions.

W

Beamforming weights. W is an N-by-L matrix,
where L is the number of beamforming directions.
If the sensor array contains subarrays, N is the
number of subarrays; otherwise, N is the number
of elements.

Examples

Apply an MVDR beamformer to a 5-element ULA. The incident angle
of the signal is 45 degrees in azimuth and 0 degree in elevation.

% Signal simulation
t = (0:1000)';
x = sin(2*pi*0.01*t);
c = 3e8; Fc = 3e8;
incidentAngle = [45; 0];
ha = phased.ULA('NumElements',5);
x = collectPlaneWave(ha,x,incidentAngle,Fc,c);
noise = 0.1*(randn(size(x)) + 1j*randn(size(x)));
rx = x+noise;
% Beamforming
hbf = phased.MVDRBeamformer('SensorArray',ha,...'PropagationSpeed',c,'OperatingFrequency',Fc,...'Direction',incidentAngle,'WeightsOutputPort',true);
[y,w] = step(hbf,rx);