## Forums Search for: Beamforming

## Which micros should I buy?

inHi, I need some help to decide which type of microphone would be best suitable for a 1D linear audio array for sound source localisation...

Hi, I need some help to decide which type of microphone would be best suitable for a 1D linear audio array for sound source localisation and beamforming. In the moment I have pretty cheap omnidirectional electret condenser microphones. But the problem is that the computet AOA is only quite accurate really close (

## Beamforming literature???

inHey Everyone, Has anyone got any good suggestions on reading material on beam steering/forming/profiles (not sure what the correct term is)? ...

Hey Everyone, Has anyone got any good suggestions on reading material on beam steering/forming/profiles (not sure what the correct term is)? I?m trying to implement simple algorithms in matlab and the results aren?t looking as expected (even for delay and sum techniques). I?m using Sonar Signal Processing by Richard O. Nielsen at the moment, but having no joy! I don?t seem able to generate ...

## Acoustic Beamforming Question

inI always assumed that sensors for a beamformer had to be spaced at least lambda/2 (half a wavelength) apart else we get spatial aliasing. Is...

I always assumed that sensors for a beamformer had to be spaced at least lambda/2 (half a wavelength) apart else we get spatial aliasing. Is this true for acoustic arrays too? I have seen papers on small arrays (circular say) for mobiles and such like. Let us asume that the mics are 1cm apart giving a wavelenth of 0.02m and a frequency (min) of 16.5kHz. Not much use is it? Hardy

## MUSIC Aglorithm (Source Localization)

inHi, I am trying to understand the MUISC (Multiple Signal Classification) algorithm. I am new in this topic. So, I am sorry if my questions seem...

Hi, I am trying to understand the MUISC (Multiple Signal Classification) algorithm. I am new in this topic. So, I am sorry if my questions seem so elementry. First of all, I would like to make sure that Source Localization is different than beamforming. Even though in Source Localization, we are dealing with phase arrays, but the goal is not to form (amplify) the beam in one direction and suppr...

## summer school/course

Hi guys, I am looking for some summer school/courses in Euro or USA 2007 regarding: multirate, subband signal processing OR beamforming,...

Hi guys, I am looking for some summer school/courses in Euro or USA 2007 regarding: multirate, subband signal processing OR beamforming, microphone array But it is really hard to find those summer school/courses. Does anybody have any clue? Your help is really appreciated! Best regards

## Locally Incoherent Scattering

Dear all, I am a research student. I am trying to simulate third example from this paper "Robust Adaptive Beamforming For General Rank Signal...

Dear all, I am a research student. I am trying to simulate third example from this paper "Robust Adaptive Beamforming For General Rank Signal Models". I do not know how to simulate the recieved data at the sensor elements. Is it that I just use a some number of angles and obtain the corresponding direction vectors and multiply with the signal? But that seems like coherent local scattering from ...

## matlab code?

inI need help with implementing a beamformer in matlab. I have a received field on an array. From what I understand I should do a fft and then...

I need help with implementing a beamformer in matlab. I have a received field on an array. From what I understand I should do a fft and then multiply with a exponential function that represents the phase shift. I´m having trouble with the code-writing in matlab, does anyone have a some easy beamforming example code in matlab? My goal is to make a BTR (bearing-time-recorder) Help would...

## Wimax 802.16e preamble...

hi, I've been reading the 802.16e standar because I need to know how the Uplink frame preamble is...I need to used it as a "training...

hi, I've been reading the 802.16e standar because I need to know how the Uplink frame preamble is...I need to used it as a "training sequence" because I don't have anything more to use for implementing adaptive beamforming on Wimax Mobile Scenario. Could someone explain me how is this preamble made?I'm not being able to understand it...but I need it Thanks a lot!!!!!

## beamforming question/help...

inI've got a question regarding weight calculation in a beamformer... In previous work, I was able to ADAPTIVELY determine weights...

I've got a question regarding weight calculation in a beamformer... In previous work, I was able to ADAPTIVELY determine weights using something like LMS, but I needed to generate an actual inbound signal, noise, reference, interferers and what-not... What I'd like to do now is pick a few directions in which to intentionally form beams, and other directions to intentionally form nulls. Th...

## Zeroforcing precoding/beamforming

inHi, I am trying to implement broadcast MIMO channels. In that i am using zeroforcing precoding which is calculated as: W = H' *...

Hi, I am trying to implement broadcast MIMO channels. In that i am using zeroforcing precoding which is calculated as: W = H' * inv(H'*H); where H is the channel matrix. To my understanding, H * W should then be I (identity Matrix). the problem that i am facing is whenever i run the above equation in matlab, i get the following warning message. Warning: Matrix is close to singu...

## Covariance matrix for MUSIC

inhi guys.. I am in the process of doing a project on implementation of MUSIC algorithm for beamforming. I want to know as to how to create a...

hi guys.. I am in the process of doing a project on implementation of MUSIC algorithm for beamforming. I want to know as to how to create a covariance matrix. For example if we have 3 antennas and we are taking 5 snapshots of the incident signal, then how do we get the covariance matrix of the input data. I know the formula to find covariance of two signals. My confusion is for two sequences...

## adaptive beamforming

I'm trying to simulate a adaptive beamformer. I refered to the block diagram of GSC in "adaptive filter theory" of S.Haykin,P.257.I'm a...

I'm trying to simulate a adaptive beamformer. I refered to the block diagram of GSC in "adaptive filter theory" of S.Haykin,P.257.I'm a little confused with the constraint matrix and quiescent weight vector. I'm wondering about how to built the signal-blocking matrix 'Ca' and how to determine the constraint matrix numerically. Any help is appreciated!

## Is there an actual definition for "direction of arrival"?

inHi, This is a beamforming question, but I thought perhaps some of the SP people might know the answer to this question, as it is a...

Hi, This is a beamforming question, but I thought perhaps some of the SP people might know the answer to this question, as it is a commonly enough occurring term in SP applications. I am a mathematician working on some interferometric problems, and I find myself having trouble getting an actual definition of "direction of arrival" (or DOA). Some older analyses using linear antenna array...

## Phase delays and IPP

Hi all, I'm in need of knocking up a simple delay mechanism for a beamforming project and have working delay and sum method in place at the...

Hi all, I'm in need of knocking up a simple delay mechanism for a beamforming project and have working delay and sum method in place at the moment although this is creating a small overhead with samples being stored. I'd like to implement a phase delay algorithm to minimise this overhead and was wondering if anyone can point me in the right direction. Is there a filter in the Intel IPP libra...

## circular array beamforming

Dear all I am trying to calculate the broadband radiation pattern(beampattern) of a circular array beamformer operating in a given frequency...

Dear all I am trying to calculate the broadband radiation pattern(beampattern) of a circular array beamformer operating in a given frequency range(1 octave) such that the main lobe response is approximately similar for all frequencies i.e the beampattern is frequency invariant I am trying to do that in MATLAB , I need help references matlab documentation or any usefull papers please help...

## 2d array pattern

inHi, I've been trying lately to plot an 2D array beamforming diagram, pointing in a direction ele and az as a function of the incident angle....

Hi, I've been trying lately to plot an 2D array beamforming diagram, pointing in a direction ele and az as a function of the incident angle. From the textbooks I've managed to understand that to plot the array pattern as a function of the incidence angle then the array pattern value depends on the difference of the sines rather than the difference of the angles themselves. At lea

## c6711 dsk & adaptive filter problem

inHi everyone, I'm a student working on modified Griffith-Jim beamforming for my masters project. I'm implementing this algorithm in TI's c6711...

Hi everyone, I'm a student working on modified Griffith-Jim beamforming for my masters project. I'm implementing this algorithm in TI's c6711 dsk, and also using PCM3003 codec to get two input's from the microphones. I'm trying to reduce the background noise using an adaptive filter (its based on NLMS). I have done the implementation in c-code in CCS, but I have a bit of problem with t...

## Multiple Beam Digital Beamforming

inHello, I am working on my senior design project and was hoping I could find some help. I need to design a MATLAB program which generates...

Hello, I am working on my senior design project and was hoping I could find some help. I need to design a MATLAB program which generates multiple beams for a 4x4 planar antenna array. Right now, I am assuming that I know the direction of the incoming signals (theta and phi). I have some source code which generates the beam for one incoming signal. I am not quite sure how I can extend the c...

## phase shift beamformer

Hi every one I am doing work on narrow band phase shift beamforming (frequency domain) and after doing various simulations, i decided to varify...

Hi every one I am doing work on narrow band phase shift beamforming (frequency domain) and after doing various simulations, i decided to varify beamformer practically. I was able to get data from an acoustic linear array of 24 elements spaced 0.17m apart. The omni directional source was placed at various bearings w.r.t linear array and was transmitting 4.4KHz CW pulses of 200ms duration . The ...

## MUSIC and LMS together??

inHello, sorry if I seem confused...but I'm actually confused... Could someone tell me if I need to implement a DoA...

Hello, sorry if I seem confused...but I'm actually confused... Could someone tell me if I need to implement a DoA stimation algorithm (like MUSIC or ESPIRT) with an adaptative algorithm (like LMS) on development of an intelligent beamforming system?? I mean, I don't know the DoA of the signal so, how could I use only the LMS algorithm? Is there a diference between using these algorit...