System object: phased.BeamscanEstimator
Perform spatial spectrum estimation
Y = step(H,X)
[Y,ANG] = step(H,X)
Starting in R2016b, instead of using the
Y = step(H,X) estimates the spatial spectrum
X using the estimator,
a matrix whose columns correspond to channels.
a column vector representing the magnitude of the estimated spatial
The size of the first dimension of this input matrix can vary to simulate a changing signal length, such as a pulse waveform with variable pulse repetition frequency.
[Y,ANG] = step(H,X) returns additional
ANG as the signal's direction of arrival
(DOA) when the
DOAOutputPort property is
a row vector of the estimated broadside angles (in degrees).
The object performs an initialization the first time the
Estimate the DOAs of two signals received by a standard 10-element ULA with element spacing 1 meter. The antenna operating frequency is 150 MHz. The actual direction of the first signal is 10 degrees in azimuth and 20 degrees in elevation. The direction of the second signal is 60 degrees in azimuth and -5 degrees in elevation.
fs = 8000; t = (0:1/fs:1).'; x1 = cos(2*pi*t*300); x2 = cos(2*pi*t*400); ha = phased.ULA('NumElements',10,'ElementSpacing',1); ha.Element.FrequencyRange = [100e6 300e6]; fc = 150e6; x = collectPlaneWave(ha,[x1 x2],[10 20;60 -5]',fc); noise = 0.1*(randn(size(x))+1i*randn(size(x))); hdoa = phased.BeamscanEstimator('SensorArray',ha,... 'OperatingFrequency',fc,... 'DOAOutputPort',true,'NumSignals',2); [y,doas] = step(hdoa,x+noise); doas = broadside2az(sort(doas),[20 -5]);