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System object: phased.BeamspaceESPRITEstimator
Package: phased

Perform DOA estimation


ANG = step(H,X)


    Note:   Starting in R2016b, instead of using the step method to perform the operation defined by the System object™, you can call the object with arguments, as if it were a function. For example, y = step(obj,x) and y = obj(x) perform equivalent operations.

ANG = step(H,X) estimates the DOAs from X using the DOA estimator H. X is a matrix whose columns correspond to channels. ANG is a row vector of the estimated broadside angles (in degrees).

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.

    Note:   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.


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 45 degrees in azimuth and 60 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;45 60]',fc);
rng default;
noise = 0.1/sqrt(2)*(randn(size(x))+1i*randn(size(x)));
% construct beamspace ESPRIT estimator
hdoa = phased.BeamspaceESPRITEstimator('SensorArray',ha,...
% use the step method to obtain the direction of arrival estimates
doas = step(hdoa,x+noise);
az = broadside2az(sort(doas),[20 60]);
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