# Questions tagged [beamforming]

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

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### 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 (...
2k views

### Difference between 'conventional' and 'adaptive' beamformers?

This might be a terminology question but I am not sure. Basically, what is the difference between conventional beamformers, and adaptive beamformers? I thought that all beamformers were inherently ...
842 views

### Can a narrowband beamformer be used for speech separation

In my master thesis I am trying to implement a beamformer. I've already done the delay-sum part 1 year ago. I have been told: in FIR filtering we can do FFT --> null the unwanted frequency bin --> ...
259 views

### Is it possible to do further beamforming on already beamformed data?

I've a circular array of eight FM antennas. I'm doing digital beamforming to form eight beams with the following beam patterns: The objective is to reduce my side lobes even further, and to get ...
2k views

### Intuitive interpretation of Fourier transform in beamforming

When applying Fourier transform in time domain the signal will be carried to frequency domain. And when we apply Fourier transform in spatial domain the signal will be carried to directivity domain. ...
972 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 ...
728 views

### Calculating Beam pattern, Directivity of microphone array

As answered in Relationship of Fourier Transform and Spatial Directivity Pattern the relation between directivity pattern and weights is given. But I am bit confused, I have Beamformer weights (...
231 views

### Question on spatial sampling for non-linear and/or non-uniform arrays

I am a little confused as to how to compute the nyquist criterion for a sensor array that is not linear, and/or non-uniform. For the linear, uniformly spaced case, the spatial nyquist is delimited by ...
502 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. ...
1k views

### Directivity Pattern of microphone array

Directivity pattern of a microphone array is fourier transfrom of microphone weight values. By modifying the amplitude weights, we can modify the shape of the directivity pattern. I can really see ...
21 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 ...
149 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 ...
49 views

### Physical Interpretation of $\mathbf A$ beamforming Matrix

The directivity of an array is defined as: $$D = \frac{1}{2} \int_{-1}^{1} \lvert B_{u}(u)\rvert^{2} du$$ Where $B_{u}(\cdot) = \mathbf{w}^{H} \mathbf{v}(\cdot)$ is the beampattern of the array in ...
187 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 ...
1k views

### Calculating covariance matrix for MVDR beamforming

I am trying to calculate the covariance matrix that is required for the calculation of an MVDR beamformer. I am getting confused as to how to calculate it. I have an array of 3 microphones each with a ...
186 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 ...
189 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 ...
820 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 ...
93 views

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### IFFT of Microphone Array Directivity Response

I am implementing a microphone array simulation in my thesis. My prof and many documents indicates that microphone array behaves like filters in DSP but instead time-frequency domain there exists ...
146 views

### Microphone Array null steering unexpected results after IFFT

I am writing an open source microphone array simulation program:SharpEar. When I give uniform weight to microphone array elements, the result in the angle is a sinc function as expected. There are 41 ...
424 views

### use of complex conjugate of weight vectors in beamforming literature

in beamforming literature, people generally quote the following as a starting point: $y(k) = \sum_{i} w_i^*\cdot x_i(k)$ Here: i varies from 1 to N where N is the number of sensors $w_i^*$ is the ...
27 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 ...
27 views

### Beamformer does not preform as expected

Sorry for the long post, I have no idea where is my mistake soI am adding everything needed to recreate. I have added some directional noise to audio files in this dataset. I am generating a ...
25 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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### 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 ...
35 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 ...
18 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 ...
19 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 ...