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collectPlaneWave

System object: phased.ReplicatedSubarray
Namespace: phased

Simulate received plane waves

Syntax

Y = collectPlaneWave(H,X,ANG)
Y = collectPlaneWave(H,X,ANG,FREQ)
Y = collectPlaneWave(H,X,ANG,FREQ,C)

Description

Y = collectPlaneWave(H,X,ANG) returns the received signals at the sensor array, H, when the input signals indicated by X arrive at the array from the directions specified in ANG.

Y = collectPlaneWave(H,X,ANG,FREQ), in addition, specifies the incoming signal carrier frequency in FREQ.

Y = collectPlaneWave(H,X,ANG,FREQ,C), in addition, specifies the signal propagation speed in C.

Input Arguments

H

Array object.

X

Incoming signals, specified as an M-column matrix. Each column of X represents an individual incoming signal.

ANG

Directions from which incoming signals arrive, in degrees. ANG can be either a 2-by-M matrix or a row vector of length M.

If ANG is a 2-by-M matrix, each column specifies the direction of arrival of the corresponding signal in X. Each column of ANG is in the form [azimuth; elevation]. The azimuth angle must be between –180° and 180°, inclusive. The elevation angle must be between –90° and 90°, inclusive.

If ANG is a row vector of length M, each entry in ANG specifies the azimuth angle. In this case, the corresponding elevation angle is assumed to be 0°.

FREQ

Carrier frequency of signal in hertz. FREQ must be a scalar.

Default: 3e8

C

Propagation speed of signal in meters per second.

Default: Speed of light

Output Arguments

Y

Received signals. Y is an N-column matrix, where N is the number of subarrays in the array H. Each column of Y is the received signal at the corresponding subarray, with all incoming signals combined.

Examples

expand all

Simulate the received signal at a 16-element ULA composed of four 4-element ULAs.

array = phased.ULA('NumElements',4);
subarrays = phased.ReplicatedSubarray('Subarray',array,'GridSize',[4 1]);

Simulate two signals received from 10° azimuth and 30° azimuth. Both signals have an elevation angle of 0°. Assume the propagation speed is the speed of light and the carrier frequency of the signal is 100 MHz.

y = collectPlaneWave(subarrays,randn(4,2),[10 30],100.0e6,...
    physconst('LightSpeed'));

Algorithms

collectPlaneWave modulates the input signal with a phase corresponding to the delay caused by the direction of arrival. This method does not account for the response of individual elements in the array and only models the array factor among subarrays. Therefore, the result does not depend on whether the subarray is steered.