How can I find the incident angle of a 4x4 array that is divided from 1 Tx and 1 Rx channel using Phased Array Toolbox?

We are designing a phased array system using 4x4 elements from 1 Tx and 1 Rx on a transceiver. Each of the 16 elements have an individual phase shifter on Rx and Tx line; a total of 32 phase shifters- 16 on Tx and 16 on Rx.

The system we are designing is meant to accomplish adaptive beamforming in two stages:

1. Find the direction of receiving signal and maximize it using signal strength/SNR.
2. Transmit a signal in the same direction of maximum signal strenght/SNR received on the array.

We tried using subarray configuration to achieve the sinlgle Tx and Rx signal from transceiver (see the config below,) but we quickly realized with the subarray configuration we cannot use MVDREstimator2D which in our understanding is the best signal search algorithm. Is there another signal search algorithm that can be used in our case for adaptive beamforming?

% SubArray and Array design constants 
sizeElementsA = [4,4]; %Size of SubArray
rxArray.Element = phased.CosineAntennaElement; %Element type
rxArray.ElementSpacing = [lambda/2,lambda/2]; %Spacing in between elements
rxArray.ArrayNormal = 'Z'; %Axis array is normal to
rxArray.Selection = [1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1];
numElementsS = 1; %number of subarrays in the full array

%SubArray design
sURA = phased.URA('Size',sizeElementsA,'ElementSpacing',rxArray.ElementSpacing,...
    'ArrayNormal',rxArray.ArrayNormal,'Element',rxArray.Element);

%Array design
aURA = phased.PartitionedArray('Array',sURA,'SubarraySelection',rxArray.Selection,...
    'SubarraySteering','Custom');

Answer 1

[Honglei Chen]

If all you care is just this 4x4 array, then you may just want to use a regular URA. It's not clear why you opt in a PartitionedArray when all elements are in the same partition.

HTH

[Nicholas Sacco]

We used PartionedArray to use the single subarray we created in to a URA. The reason why we used subarray is to make sure that the algorithm only gets one SNR/RSSI; which according to my understanding in case of a simple 4x4 URA would require 16 distinct SNR/RSSI from each recieving element.

We have a single point where we can measure SNR/RSSI of the recieved signal even though we have 16 antenna elements, they are merged to connect to one Rx channell. That said, we do have individual phase shifters on each channel to add weights to indivdual phase shift resulting in steering the beam.

I am looking for a DOA and Beamformer algorithm that can work with our system design.

[Honglei Chen]

Thanks for the clarification, I agree with your choice of subarray then. But this being said, as you mentiond in your comment, such an array ahs only one Rx channel so there is no way for you to use a typical DOA algorithm. Assuming the scene is stationary, you can try to scan all the directions and then pick the direction that gives you the maximum power return.

HTH

Answer 2

[Hind Thanoon]

Excuse me please,

Can I Know if their is any deferent between phased array system toolbox in matlab 2019a from any other version?

[Honglei Chen]

I'm not sure if I can pin point what you are looking for but you can see the updates in 2019a through release notes

https://www.mathworks.com/help/phased/release-notes.html

HTH

[Hind Thanoon]

Thank you sir.