Questions tagged [beamforming]

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

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14 views

Calculation of the clutter component of the space-time snapshot

I've encountered a silly problem during the implementation of SMI beamformer. I have KASSPER project datacube from IEEE dataport as my data and I want to calculate covariance matrix from that datacube....
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55 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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59 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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44 views

Radar type application for narrow band only?

Not sure if this is the proper forum to ask this question, but still I am trying my luck. I am looking for an application (in any area, medical, defence, or any other area) if exist, such that we want ...
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16 views

Multi-input Single-output communication system

In case of communication in MISO system, if we have a system of 4 x 1, which means 4 transmitter with 1 receiver. Will the received signal be a vector of dimension 4 x 1 ? Or it will be 1 x 1 since ...
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31 views

What is the driving Voltage?

While I was looking into ultrasonic transducer in order to transmit and receive a beam, I came across specification of a transducer stating driving voltage as 20Vrms. I am not sure what actually does ...
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57 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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How to derived an equivalent real-valued system model of the complex value MISO system with beam forming?

Currently I am interested in finding the equivalent real value model of the following system with beam forming vector $y = h \times \mathop {{w_1} \times {x_1}}\limits_{{\text{WANTED}}\,\,{\text{...
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14 views

How receive beamforming gain is defined?

Novice here. I'm working on a receive beamforming simulation (my first, to be frank) and I'm wondering, how shall I define "receive beamforming gain"? Should it be the ratio of SNR without beamforming ...
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23 views

Calculate SINR and Array-Gain for acoustic Beamforming in Matlab

I'm struggling to understand the equation and the reasons for this equation from Matlab's acoustic beamforming example. Here is the link: https://se.mathworks.com/help/phased/examples/acoustic-...
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57 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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35 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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42 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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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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59 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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205 views

How can one improve the robustness of adaptive beamformers to signal mismatches?

Compared to standard (conventional) beamformers, adaptive beamformers such as minimum variance distortionless response (MVDR) have much better resolution and interference nulling capabilities. Briefly,...
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60 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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26 views

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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84 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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33 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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89 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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97 views

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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229 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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48 views

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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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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84 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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301 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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99 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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417 views

Practical wideband digital beamforming for large arrays in radar applications

I do understand the mathematics behind digital beamforming but I am not sure how such systems are practically implemented. For example, in a typical wideband FMCW radar operating in S-band, the (...
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328 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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165 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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1k 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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123 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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840 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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144 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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114 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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193 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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264 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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240 views

Direction of arrival and distance to source

Suppose we have $3$ receivers $a,b,c$ and one wave source which are all located on the same $XY$ plane and we do not know the position of only $c$ on the plane. Assume a plane wave is transmitted $s(...
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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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339 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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189 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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390 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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196 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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2answers
211 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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957 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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1k views

Relationship of Fourier Transform and Spatial Directivity Pattern

I am reading over and over the Section 1.2 of most understandable mic array tutorial for me . A sound wave is dependent on time and space which can be observed in the great link. But I can't ...
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244 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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936 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 $f_{x_s} = \frac{\sin \theta \cos \phi}{\lambda}$ where $\...