# Questions tagged [lms]

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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 ...
210 views

### Recursive DCT implementation

I am trying to understand the recursive implementation of the DCT on the input signal (used for LMS filtering) according to the pictures below. The pictures and formulas are taken from the paper: "...
224 views

### Why Wiener filter is not optimal?

I am investigating Wiener filter in the frequency domain, given by $$W(\omega) = \frac{S_{ud}(\omega)}{S_{uu}(\omega)}$$ where $S_{xy}(\omega)$ is the cross-power spectral density (CPSD), see scipy....
26 views

### Block NLMS vs Affine Projection LMS

I am studying Block Normalized LMS, and when I compare this with Affine Projection LMS (if updated every M samples) I think that they are the same. I would really appreciate if anyone can point out if ...
73 views

### Length of the FIR filter in LMS algorithm

I'm working on an interference cancellation problem where interfering signals are two linear FM chirps of different slopes and the data signal is a spread spectrum signal. I wanted to know how does ...
295 views

### Feedback Filtered-x LMS algorithm: question about theory

I was reading some of papers about the Active Noise Cancellation; in particular about the Filtered-x LMS algorithm, also known as FxLMS. It seems that classic FxLMS (also called Feedforward FxLMS) ...
189 views

### Active Noise cancellation for non periodic signals

I observed that the coded algorithm for active noise cancellation is not able to cancel some of the signals like a human voice. Is there any solution for this? Can we really cancel non-periodic ...
36 views

### NLMS Echo Cancellation: How do we estimate when the time-step at which the Far-End Echo will be generated?

I'm new to this domain. From my understanding, we do the following in our algo: ...
203 views

### Equalizer design for spectral gain flatness

I'm trying to design an equalizer for spectral flatness over a 100MHz signal for an LTE channel emulator. A channel emulator simply multiples channel coefficients with an external signal from a signal ...
79 views

### Normalized LMS with a posteriori Error and Woodburry's Matrix Inversion

I was going through this paper and the author mentioned that we can prove the following using the Matrix Inversion Lemma (AKA Woodburry's Matrix Inversion Identity): Using matrix inversion lemma we ...
96 views

### Impulse Response and Frequency Response of a FBLMS filter

Suppose I work with sampling frequency FS and block length of L. I implemented the Frequency-domain Block LMS (FBLMS) algorithm ...
28 views

### Automatic Gain Control (AGC) by using Least Mean Square (LMS) Method

I am try to do Automatic Gain Controller by using Normalized LMS. Can somebody help me? I could not find how to start it. I am try to do it on MATLAB.
29 views

### NLMS algorithm greatly attenuating signal

Im writing an NLMS MATLAB program to remove powerline noise from ecg signals. I sweep through tap widths and learning rates which get the best SNR values. Some of the combinations produce great SNRs ...
43 views

### what is the difference between LMS and MPC?

I do understand that MPC is a control method and requires known model in the feedback path. LMS, on the other hand, is more like an adaptive filtering, which estimates the tap coefficients yielding ...
407 views

### MATLAB model for equalizer using LMS algorithm adaptive filter and unexpected output curve

The MATLAB code below is for equalizer using lms algorithm adaptive filter and then plotting MSE (Mean Square Error) Vs Iteration numbers ...
50 views

### modified LMS algorithm

Suppose am given the modified LMS Algorithm below: $W\left(n+1\right)\:=\:\alpha W\left(n\right)+2\mu e\left(n\right)X\left(n\right)$ Where: $\mu$ is the step size $e$ is the error signal at the ...
87 views

### How to choose a fixed adaptation step for decision feedback equalizer

How do I choose $\mu$ - a value of a step size for adaptation in a decision feedback equalizer (DFE) with adaptive reference control (ARC)? For a regular adaptive FIR filter an adaptation step depends ...
33 views

### Capture the ambient sound

I sit in a cafe and start recording my voice, reading a poem. Then I sit at my room, at complete isolation, and I read the same exact poem once again and record it. Now, Considering I have these two ...
1k views

I am writing LMS filter to suppress noise in wav file (I know there are many modules to do this but I need to write LMS manually now as I will translate it into C later). According to this answer, ...
151 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 ...
209 views

### Two type of calculating R in steepest-descent modeling algorithm

I have wrote this algorithm for steepest descent: ...
Trying to perform system identification in the following state-space model  \begin{bmatrix} x_{1}(n)\\ x_{2}(n) \\ x_{3}(n)\end{bmatrix}=\begin{bmatrix} a_{11} && a_{12} && a_{13} \\ ...