System object: phased.BeamspaceESPRITEstimator
Perform DOA estimation
ANG = step(H,X)
Starting in R2016b, instead of using the
to perform the operation defined by the System
object™, you can
call the object with arguments, as if it were a function. For example,
= step(obj,x) and
y = obj(x) perform
ANG = step(H,X) estimates the DOAs from
the DOA estimator
a matrix whose columns correspond to channels.
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.
The object performs an initialization the first time the
is executed. This initialization locks nontunable
properties (MATLAB) 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
to unlock the object.
Estimate the directions of arrival (DOA) 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° in azimuth and 20° in elevation. The direction of the second signal is 45° in azimuth and 60° in elevation.
Create the two signals arriving at the array.
fs = 8000; t = (0:1/fs:1).'; x1 = cos(2*pi*t*300); x2 = cos(2*pi*t*400); array = phased.ULA('NumElements',10,'ElementSpacing',1); array.Element.FrequencyRange = [100e6 300e6]; fc = 150e6; x = collectPlaneWave(array,[x1 x2],[10 20;45 60]',fc); noise = 0.1/sqrt(2)*(randn(size(x)) + 1i*randn(size(x)));
Set up the beamspace ESPRIT estimator and solve for the DOAs.
estimator = phased.BeamspaceESPRITEstimator('SensorArray',array, ... 'OperatingFrequency',fc,'NumSignalsSource','Property','NumSignals',2); doas = estimator(x + noise); az = broadside2az(sort(doas),[20 60])
az = 9.9972 45.0061