Narrowband beamforming in transmission

Hi everybody. I am studying at university the concept of beamforming and I would like to design a simple beamformer in matlab/simulink for a transmitting system. I am studying matlab documentation, but it sems to me that the most of the exampes and functions are specifics for a receiving system. Can anyone please help me to understand how to implement it? For now, it should be just a very simple system, e.g. linear or cirular antenna array with few sensors and using as signal to transmit a sine/cosine or something like that.

Thanks to anyone will help!

[Valerio Gloria]

Edit: Maybe I could use the provided function both for Tx and Rx? For example this function.

Answer 1

[Bjorn Gustavsson]

In the direction of yor transmitted beam the waves from the different antennas have to interfere constructively. To achieve this you have to shift the transmitted signals. Something like this (barring sign-errors and whatnot...):

r0 = [0 0 0]; % reference antenna
r1 = [x1,y1,z1]; % one of the other antennas
dr = r1 - r0;
e_n = [randn(1,2),rand(1)];
e_n = e_n/norm(e_n); % some random direction to transmitt towards
S0 = A*exp(1i*w*t)
dphi = 2*pi/lambda*dot(dr,e_n);
S1 = A*exp(1i*(w*t-dphi));

From that you should be able to loop over your antenna array.

HTH