Questions tagged [beamforming]

Forming a beam (directional gain) and, sometimes, shifting the beam direction.

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29 views

Is there a term called “Fourier Beamforming”?

I understand delay and sum beamforming, where we want to add the signals obtained from different sensors. But adding different time samples from different element of the array depending on the angle ...
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36 views

Sign of manifold vectors in monostatic phased-array radar

I am reading some notes where the impulse response of phased-array to is given by; $$ \beta S(\theta, \phi) \bar{S}^H(\theta, \phi) \cdot \delta(t-\tau) $$ where \begin{align} \bar{S}(\theta, \phi)...
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DOA estimation with reverberation and directional interference

I have a 3D 4 microphone array. I wish to estimate the DOA of the source. I am working on a scenario with directional interference and reverberations. The first approach that comes to mind is using ...
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42 views

Beamformer implementation methods

I'm currently reading articles about the different type of beamformers. This spatial filtering is gonna be used for acoustic purposes, to focus the beam on the person we need to hear talking in a ...
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39 views

Digital beamforming and phase shift stage insertion

I have read some literatures about the different topologies of beamforming and it came to my mind a question : where is applied the phase shift for each channel depending on the type of topology/...
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55 views

How to generate a beam pattern from a beamformer on 3D

given a 3D microphone array with $M$ microphones, $d(f,\Theta)\in \mathbb{R}^{f\times M}$ is the steering vector for a given direction $\Theta=(\varphi,\theta)$, inclanation and azimuth respectively. ...
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32 views

Steering vector for beamforming in 3D

I am trying to implement a steering vector in 3D for beamforming. Let $A\in \mathbb{R}^{M\times 3}$ be a matrix containing the $(x,y,z)$ coordinates for $M$ sensors and the impinging source direction ...
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Question on unitary DFT matrix based beamforming

I am trying to experiment with digital beamforming for the first time & found a lot of literature making use of unitary DFT based beamforming but wasnt able to figure why(or how) DFT-based ...
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82 views

Proving that a product of matrices invertible

Given $R_x$ a Positive Definite (PD) covariance matrix of size $M\times M$ and $C$ a full rank $M \times N$ matrix, I want to prove that $C^* R_x^{-1} C$ is invertible to derive the Linearly ...
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28 views

Hot to generate image through Delay and Sum algorithm

I want to generate image through Delay and Sum algorithm. The list of the formula are attached, I have calculated rij(t) which is nothing but signals in time domain (1xn matrices), and the tij(x,y) (...
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84 views

Amplify Sound From Known Direction

I have microphone array which records sound. There is one main sound which direction I know and some noises in the background. Now I want to selectively amplify sound from known direction. This looks ...
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How to create test vectors for wideband beamforming aplications?

I'm trying to create test vectors for a beamforming algorithm I'm simulating in Matlab. I have a complex signal and I want to create the signal as seen by each antenna element. This will allow me to ...
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Implementing MVDR beamformer in the STFT domain

I am trying to implement an MVDR beamformer for the first time. I was reading a couple of papers and books with many different notations and I am a bit confused. In my case, without loss of ...
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45 views

Beamforming but only for total power?

Is there a method to speed up beam-forming if you only care about the total power in a given direction, or total power in frequency groups? I've googled this, and can't find anything. My intuition ...
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46 views

frequency/phase offset estimation in satellite DOA beamforming applications

In satellite QPSK demodulation, we first estimate and remove the phase offset introduced by the channel. Then, we demodulate the baseband information bits (I & Q channels). In satellite DOA ...
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67 views

Linear Combiner Based LMS Transfer Function

I am currently working on narrowband beamforming and looking to compute the transfer function for a linear combiner based LMS. While doing a quick search I have found the following article which ...
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2answers
206 views

Tetrahedral microphone array beamforming

I have a microphone array of 4 channels taken as channels [6,10,22,26] from Eigenmike spherical microphone array. I wish to do 3D beamforming and create $8\times 4$ beams, 4-elevations with 8 ...
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141 views

How to realistically represent antenna elements in phased array system alongside it's 3D gain response?

Please find the figure below where I've plotted a 3D gain response(in dB) of an antenna array system for beam-steering application and overlaid the actual antenna element(in red X marks surrounded by ...
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1answer
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Beamforming back lobes question

When performing a conventional digital beamforming I see in some textbooks they show beam patterns as where the arrival angle ranges between -90 to 90 degrees. But then other places show the full ...
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25 views

Can the j be equal to k in the first formula ?In MISO system

In this system model,the received signal available for RF EH at each RX_k is given by However,its SINR formula is given by We can find that author said the j can't be equal to k,but their range are ...
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38 views

How multi layer map to different beams in LTE Beamforming

I understand for SU-MIMO Beamforming single layer maps to all antennas with phase shift applied to create beam. Also I understand in this case all beams will be carrying same signal (say s1). But in ...
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74 views

Beamforming question

I'm working on a beamforming network. Every node in the network is half-duplex and has a linear antenna array that is capable of digital beamforming. A receiving node can be capable of forming any ...
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282 views

how to calculate the maximum obtainable directivity for a microphone array?

Introduction The relationship between the maximum obtainable directivity and aperture of an antenna is described by: $$ D = \frac{4\pi A_e}{\lambda^2} $$ Where $D$ is the directivity, $A_e$ the ...
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311 views

Time-Delay beamforming delay computation

I'm trying to implement a beamforming algorithm in python and I'm stuck with the time-delay computation for a rectangular array. I'm using the following equation to compute the delays based on the ...
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147 views

Calculation of Correlation Matrix

In the description of any Beamforming Technique for microphone array signal processing there is a usage of the co-relation matrix. What is the use of calculating such a co-relation matrix in such ...
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695 views

what is an alpha filter?

Currently, I'm working on adaptive beamforming using LMS approach, so they change the value of the step factor adaptively in which one of the steps is to pass the weight vector through an alpha filter....
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112 views

Generalized Sidelobe Cancelling performance

I'm tinkering with different adaptive beam-forming algorithms for a research project in which I want to use a Uniform Rectangular microphones Array (URA) to isolate speech in a room. I am determining ...
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97 views

What is the best way to show beamformer enhances signal of interest over interference

I need to study an array's performance in terms of interference. I have already analyzed the array's white noise gain which is the ratio of output and input SNR of the beamformer i.e. $\rm{SNR_o} / {...
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794 views

Beam width of linear array using MVDR beamformer

I did delay and sum beamforming technique and MVDR beamforming technique in MATLAB in ...
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140 views

Superdirectivity Beamformer for Circular microphone array

The matrix below represents the inverse of correlation matrix assuming diffuse noise field. I am unable to figure out the values of the elements of this matrix. how to calculate $c_{M}(\omega)$ ?
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110 views

Design of a filter with given bandwidth and sidelobe level using Parks–McClellan algorithm

I want to design a filter (beamformer) with a given bandwidth (beamwidth) and sidelobe level using Parks-McClellan algorithm. I use "firpm" function of MATLAB. however, I cannot reach a solution for ...
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1k views

Delay-and-sum beamforming: implementing steering in C

I am currently trying to understand how delay-and-sum beamforming works. I have found this website which explains the process of this technique very well in which the following C code is provided: <...
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316 views

How to compute beam pattern given a delay-and-sum filter in spectral domain?

Given a two-mic system (the mic spacing $d$ is known), how can I compute the beam pattern (see the Figure below) over frequency and angle $g(f,\theta)$ for a pair of spectral filters ($H_0$ for ...
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182 views

Relationship between matrix rank and beamforming

I always encounter the term matrix rank in papers related to beamforming. I am only familiar with the basics of beamforming (delay sum beamformer, basic capon). Can someone explain the significance of ...
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350 views

What is homogeneous noise field?

What is the formal definition of homogeneous noise field? Is there any example of it? Thanks.
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188 views

Filter signal for beamforming and phase response

I was wondering this for quite some time but couldnt find a satisfied answer. Seems like not a lot worry about phase response in general. But maybe I'm thinking about it in a wrong way... I want to ...
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234 views

Would a visible light beamforming “telescope” be feasible?

If you had a phased array of high speed photodiodes that were spaced sufficiently far apart, would it be possible to apply beamforming theory to create a steerable visible light "telescope"? ...
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209 views

MVDR Beamformer, minimize but do not change pattern in main beam

Is there a way to minimize all signals that are not coming from the mainbeam? I would like to keep the main beam, or at least +-3° around the main peak stable. When I estimate the covariance from ...
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883 views

Spatial sampling frequency equation

Upon reading this microphone array tutorial, I'm stuck in the following piece: The spatial sampling frequency along the x-axis is given by $f_{x_s} = \frac{\sin \theta \cos \phi}{\lambda}$ ...
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1k views

Difference between Uniform Linear Array (ULA) 3 dB beamwidth and bearing resolution

Is there a difference between linear array 3dB beam width and linear array bearing resolution ?
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125 views

Beam pattern for a linear array comprised of rectangular transducers

I am looking for the beam pattern of a linear array with uniform spacing, $d$, between $n$ elements. I know for an array comprised of circular pistons it can be derived from $$\frac{1}{n}\frac{\sin[...
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1answer
686 views

DSP with 8+ inputs for simple beamforming

Does anyone know of a DSP that is cheap and has 8+ inputs (8 I2s mics) and that can perform beam forming calculations? I'm super new to circuit design so preferably one thats beginner friendly. ...
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144 views

Beam Former linear array antenna

How can I design a beam former (with weigth vector $w$) that protects a signal coming from an angle of arrival $\theta_0$ and completely suppresses signals coming from $\theta_1,\theta_2,...,\theta_k$?...
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869 views

Beamforming techniques - pros and cons

I would like some advice on which beamforming method to use from someone with experience in the field. I have radar data from the ocean which has been transmitted by an omnidirectional transmitter ...
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2k views

Beamforming using MATLAB

I'm attempting to beamform some data which has signals coming from all directions in a 180 degree range. I found an example of using the phased array toolbox, in MATLAB, to beamform a signal in https:...
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191 views

What does the $n$ do in $1/(j \omega)^n$

I'm currently working through a research paper on beam forming. In this paper a magnitude compensation is introduced to compensate for frequency dependency. Due to other calculations low frequencies ...
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1answer
240 views

Which parameters defines a polar plot?

I need to convert a polar plot into a short array of 3-5 values. This array should describe the polar plot as best as possible. For example, I know that I can use the beamwidth which is also known as ...
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968 views

Delay and sum Beamforming

What is the difference between the weight vector (w) and the steering vector a(θ)? I initially assumed they were the same thing, but the literature seems to be to be a bit fuzzy with this (or maybe ...
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324 views

Beam resolution improvement of linear array using MVDR beamformer

One of the major advantages of using MVDR beam former is to improve bearing resolution as compared to conventional delay & sum beam forming. The bearing resolution is defined by 3 dB beam width of ...
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227 views

Narrowband DOA Beamforming techniques on Wideband signal

I'm trying to implement a tracking system (undergrad thesis) using DOA of acoustic signals. I'm testing this by playing a 2kHz sound and receiving the signal with four microphones in a ULA. So, the ...