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Problem in Beam Steering

Started by matlab2015 4 months ago4 replieslatest reply 4 months ago113 views

I am involved in steering the main beam in desired direction and producting nulls in unwanted direction. I have the following MATLAB code but when I run it , it gives me a polar plot. Also it doesn't give me the desired plot. I want to get a plot of type shown in image and to make the pattern such that it meets my requirement.

radiation pattern plot_31349.png


% Generalized Null Steering Broadside Beam former Weights Vector

clear all;close all;clc

a = 4; % Antenna elements

d = 0.5; %Spacing

f = 3e9; % operating frequency

%Input Received Signals Arrival

b = input ('The Angle of Incidence of The Desired Source Signal  : ') ;

msgbox ('Enter The Angle of Incidence of The Interference Un-Desired Source Signals Respectively ') ;

pause

for I = 1 : a-1

    A(I) = input ('The Angle of Incidence of the Undesired Interference Source Signal : ') ;

end

%Estimation of The Weight Vector of A Null Steering Beamformer

for I = 1 : a

    for J = 1 : a

        if I ==1

            S ( I , J ) = exp ( i*( 2*pi*f*d*( J-1 )*cos ( b ))/( 3*10^8 )) ;

            Z ( I ) = 1 ;

        else  

            S ( I , J ) = exp ( i*(2*pi*f*d*( J-1 )*cos ( A(I-1) ))/( 3*10^8 ))  ;

            Z ( I )= 0 ;

        end

    end

end

W = ( pinv ( S ) * Z' ) ;

%Plot of The Output Radiation Pattern

% t = 0 : 0.05 : 2*pi ;

t = 0 : 0.05 : pi ;

M = 0 ;

for I = 1 : a

    H = exp ( i*(2*pi*f*d*( I-1 )*cos ( t ))/( 3*10^8 ))  ;

    M = M + ( H * W(I) ) ;

end

M = abs ( M ) ;

polar ( t , M , '-r' ) , title ( 'The Generalized Null Steering Beam Former Output Radiation Pattern ') , 

grid on ;


[ - ]
Reply by fharrisJune 14, 2021

make the following changes

% M=abs(M);

M = 20*log10(abs ( M )) ;

%polar ( t , M , '-r' ) ,

plot(t,M,'r')


fred h

[ - ]
Reply by matlab2015June 15, 2021

Thank you very much for your kind response. I made the changes as you directed and ran the program, but it gave me the following error:


To use 'fred', the following product must be both licensed and installed:

  Datafeed Toolbox

Error in steerer1 (line 51)

fred h

[ - ]
Reply by kazJune 15, 2021

"fred h" is not a header and is not part of matlab keywords yet. It is a string meaning Fred Harris:


https://www.dsprelated.com/user/fharris

[ - ]
Reply by matlab2015June 16, 2021

Thank you very much for your kind response. Ok that's right. But now what should I do? I mean to say how can I get my desired result?