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# fft beamforming - RF Cafe Forums

Because of the high maintenance needed to monitor and filter spammers from the RF Cafe Forums, I decided that it would be best to just archive the pages to make all the good information posted in the past available for review. It is unfortunate that the scumbags of the world ruin an otherwise useful venue for people wanting to exchanged useful ideas and views. It seems that the more formal social media like Facebook pretty much dominate this kind of venue anymore anyway, so if you would like to post something on RF Cafe's Facebook page, please do.

Below are all of the forum threads, including all the responses to the original posts.

 Post subject: fft beamforming Posted: Tue Apr 12, 2005 3:09 am
i'm a beginner in this area.
i just learned about the basic algorithm of fft beamforming from internet.and want to implement the algorithm by using matlab,but i don't know how to start(ps,i'm also a new user of matlab).

can anyone give me some sample souce code, even segments are okay.
I'm really stuck in mud.

 Post subject: Beamformer Posted: Mon May 09, 2005 5:51 am
 Dear Here I give you a sample code for creating the filter coefficients of a Delay and Sum beamformer. if you have any question you can contact me on my email palange@hotmail.fr Have a nice day.[code] c = 340; % m/snfft = 128; % nfft lengthi_omega = -i*2*pi/c; % f will be variablen_mic = 7; mics = [ (-10*3:10:10*3)' zeros(7,1) ]/100;source = [-0.2 0.63]; % to be measuredfs = 22050; % Sampling Frequencyf = (0:nfft-1)*fs/nfft; % Frequency binsW = zeros(n_mic,nfft);d = zeros(n_mic,1);w = zeros(n_mic,1);r = zeros(n_mic,1); u = zeros(n_mic,1);bp = zeros(nfft,181); bps = zeros(1,181);% Filter Coeffor k = 1:n_micr(k) = norm( source - mics(k,:)); endindex = 1;for p=fd = exp(i_omega*p*r)./r; w=d.*r;w=w/abs(w'*d);W(:,index) = w; theta_v=[-90:1:90];source_n=norm(source); for theta = theta_vs=[source_n*sin(theta*pi/180) source_n*cos(theta*pi/180)];for k=1:n_mic u(k) = norm(s-mics(k,:));endd=exp(i_omega*p*u)./u; bps(theta+91)=20*log10(abs(w'*d));endbp(index,:)=bps; index = index + 1;end% here you can plot the BP as a function of DoA for any frequency. % Implementing the Beamformingstart = 1;skiprate = nfft/2;window = triang(nfft)'; num_samples = size(data,2); % data size num_blocks = ceil((num_samples-nfft)/skiprate); frame = 1:nfft;data_frame = zeros(n_mic,nfft); % frame of data ( from each mic)data_fft = zeros(nfft,n_mic); % FFT of the frames = zeros(1,nfft); % frame data (time)S = zeros(1,(n_blocks+1)*nfft/2);for m = 1 : n_blocksdata_frame = data(:,frame); data_fft = fft(data_frame'); s = sum(conj(W).*data_fft'); S(frame) = S(frame) + real(ifft(s.*window)); frame = frame + skiprate;end[\code]

Posted  11/12/2012
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