Questions tagged [beamforming]
Forming a beam (directional gain) and, sometimes, shifting the beam direction.
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What is the relationship between beamforming and Independent Component Analysis (ICA)?
My first inclination when thinking about the Cocktail Party Problem would be to use adaptive beamforming to isolate different signals, but this does not seem to be how the problem is commonly thought ...
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Is there a way to get the "mode" of several recordings? (to remove 1-off noise)
I've got several (4) not-great audio recordings of the same short (a few minutes long) performance, each taken from different microphones. I'd like one high-quality clip of the event. This is... ...
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Comparing directivity patterns of an un-tapered and tapered uniform linear array
Assume we have a uniform linear array (ULA) with N elements. We wish to compare the performance of a tapered (let us presume Taylor 4-bar, -30dB side-lobe) array to an un-tapered array. Let the ...
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Why is optimal beam-forming vector w orthogonal to channel signature?
I am looking at an online document on optimal beam-forming methods: https://www.comm.utoronto.ca/~rsadve/Notes/BeamForming.pdf (sorry I could not find author info from the pdf).
One of the strategies ...
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Using Least Mean Square (LMS) Filter for Beamforming on Linear Array in Julia
I have been trying to implement a simple LMS adaptive beamforming code. Since I don't have a MATALB license, I decided to use Julia since they are quite similar. In order to get a basic code working I ...
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Iterative beamforming IB
Is iterative beamforming (IB) an algorithm on its own, or is it an extension of the EM algorithm, how does IB differ from the latter, knowing that EM iterate 2 steps (the E step and the M step) and so ...
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How to differentiate two different signals from their combined signal
I am having two omnidirectional microphones connected in endfire configuration. I am playing a male speech from 0 degree (front direction) of the endfire microphone configuration and female speech ...
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Radar beamforming receiver combining vector estimation
I don't have much experience with radar signals. I know in the cellular system, the channel directional vector can be estimated using pilot symbols based on MMSE, EW-MMSE, and LS. Then, we can use the ...
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Is there a good beginner's book for array microphone beamforming?
I have been working in the acoustics field for a while, and recently I got myself into Matlab and Python for signal analysis and some signal processing.
After making some test and analysis tools with ...
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Can beamforming be created by transmitting same signal with different phase
As known, the basic idea of beamforming is to transmit the same signal using more transmit antennas, let's say we have $4$ transmit; leading to increase the power of the transmitted signal as well as ...
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what is the correct order of applying a nonlinear operation and downsampling (with anti-aliasing)
In UltraSound imaging, after beam-forming and obtaining the envelope, Log-compression which is a non-linear operation and scan conversion which is a 2D interpolation (with inherent down-sampling) is ...
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sound source localization - calculation of sound intensity vector angles
I'm working on an acoustic source separation problem where I want to separate the voices of a choir based on intensity vector statistics.
I'm currently implementing a paper by Günel called “Acoustic ...
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Does same data inserted to all antenna at beamforming?
I wonder do I understand beamforming right.
Question 1
Does same data inserted to all antenna at beamforming? Like figure below? The only different is through different phase shift? If it is right how ...
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Forming the estimation manifold for a 2-D beamformer
Given an array of L sensors in a uniform planar array, with known positions in space, I would like to estimate both the angles of arrival and delays from a point source under multipath conditions ...
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How to derive the "well-known" solution to Unconstrained Array Gain?
Can someone point me to a webpage or other resource that shows how to analytically solve the beamformer Unconstrained Array Gain expression in Henry Cox's 1987 IEEE paper "Robust Adaptive ...
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Why is beamforming needed in 5G?
With the advent of 5G Era, base station density
increases, the cell radius decreases, and LOS propagation
gets more dominant. So, why do we need for beamforming in 5G NR, although we have smaller ...
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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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