System object: phased.TimeDelayBeamformer
Perform time delay beamforming
Y = step(H,X)
Y = step(H,X,ANG)
[Y,W] = step(___)
Y = step(H,X) performs time delay beamforming
on the input,
X, and returns the beamformed output
X is an M-by-N matrix
where N is the number of elements of the sensor array.
a column vector of length M.
Y = step(H,X,ANG) uses
the beamforming direction. This syntax is available when you set the
ANG is a column
vector of length 2 in the form of
[AzimuthAngle; ElevationAngle] (in
degrees). The azimuth angle must be between –180 and 180 degrees,
and the elevation angle must be between –90 and 90 degrees.
[Y,W] = step(___) returns additional
W, as the beamforming weights. This syntax
is available when you set the
W is a column vector
of length N. For a time delay beamformer, the weights are constant
because the beamformer simply adds all the channels together and scales
the result to preserve the signal power.
The object performs an initialization the first time the
Apply a time delay beamformer to an 11-element array. The incident angle of the signal is –50 degrees in azimuth and 30 degrees in elevation.
% Signal simulation ha = phased.ULA('NumElements',11,'ElementSpacing',0.04); ha.Element.FrequencyRange = [20 20000]; fs = 8e3; t = 0:1/fs:0.3; x = chirp(t,0,1,500); c = 340; % Wave propagation speed (m/s) hc = phased.WidebandCollector('Sensor',ha,... 'PropagationSpeed',c,'SampleRate',fs,'ModulatedInput',false); incidentAngle = [-50;30]; x = step(hc,x.',incidentAngle); noise = 0.2*randn(size(x)); rx = x+noise; % Beamforming hbf = phased.TimeDelayBeamformer('SensorArray',ha,... 'SampleRate',fs,'PropagationSpeed',c,... 'Direction',incidentAngle); y = step(hbf,rx);