Questions tagged [adaptive-algorithms]
The adaptive-algorithms tag has no usage guidance.
66
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Filtered-X LMS algorithm and built-in MATLAB implementation
I provide a short scheme for forward explanation:
There are two sources: noise signal source and anti-noise signal source (2). Noise signal travels through primary path $h_{N_P}$ to microphone (4). ...
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0
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Recursive estimation of signal variance of strongly colored noise
I have a quasi stationary but time varying stochastic signal of which I would like to recursively (adapting to its time dependence) estimate the variance. I believe the signal could be modeled like ...
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1
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DSP microchip in Phonak products
Does anyone know which chips Phonak uses in their products to run the DSP algorithms?
Thanks.
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1
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331
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Gradient descent algorithm not converging
I wish to use the gradient descent algorithm to minimize the cost function
$$J(\mathbf{w}) = (\mathbf{w} - \mathbf{w}_{o})^{T} \mathbf{A}(\mathbf{w} - \mathbf{w}_{o})$$
where $\mathbf{w} \in \mathbb{R}...
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Implementing the NMCFLMS Algorithm for a 2 channel WGN input signal
I am just trying to implement the Normalised Multi-channel Frequency Domain Least Mean Square (NMCFLMS) algorithm for a simple 5 tap filter to estimate the filter coefficients of a 2 channel system ...
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Baseband algortihms in exisitng mobile sytems
For OFDM-based systems, many algorithms and techniques have been proposed for each baseband functionality like synchronization and channel estimation. Do practical systems like mobiles employ only one ...
6
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322
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Convergence of the RLS Algorithm for a Forgetting Factor $ \lambda < 1 $
I have a question regarding Recursive Least Squares (RLS) adaptive filter.
According to Wikipedia (Recursive Least Squares in Wikipedia), to prevent infinite memory one introduces a forgetting factor $...
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MATLAB: cannot get CMA code for polarization demultiplexing to work
[ Edit: the CMA code seems to work after all, the problem is likely elsewhere (timing recovery), see added text at the end. ]
Yesterday I implemented some CMA code for polarization demultiplexing ...
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187
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Algorithm for "adaptive phase rotation" in iZotope RX 8
I'm trying to understand how the adaptive phase rotation in iZotope RX 8 works. In the papers I've looked at, the problem is called Peak-to-Average Power Ratio (PAPR) reduction. However, they seem to ...
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1
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593
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Is the beamforming result described by this matlab code useful?
A narrow-band beamformer for $0$ degree in the frequency domain is created for $8$ sensors and compared with a usual delay and sum beamformer. The question can also be expressed as : can we have ...
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120
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LMS Adaptive Filter for system identification
i am currently attempting system identification using the LMS algorithm. The input and the output data are available and are very noisy and consists of multiple frequencies. The input and the output ...
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Grey Box system identification using LMS algorithm
The transfer function and the input output data of the system are known. The transfer function is given by $$G(s) = \frac{K}{(Js+b)(Ls+R)+K^2}$$
How are the parameters of the transfer function ...
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92
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Approximate a Known System with Adaptive Filter and an Unknown System in a Series
I am using gradient descent on an adaptive IIR filter for the below system 1. At the moment I am just assuming the known system is not there and it works fine. However, occasionally when the known ...
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1
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34
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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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2
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548
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Is a neural network an adaptive filter?
I am confused as to the difference between neural networks and adaptive filters: As far as I understand it, "neural networks" are largely used for solving inverse problems, where an unknown ...
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157
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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 ...
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Compute objective speech quality from Anritsu data
I want to compute an objective speech quality however what I have right now is the Anritsu raw data (layer between the Base Station Controller and the Mobile Switching Center), this raw data does not ...
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Bandpass before EEMD- selecting IMF outside band pass range
I have a vibration signal of 25.6 kHz where I first perform band pass filtering (7000 Hz, 9000 Hz) and then perform Empirical Mode Decomposition (EEMD).
I then want to select the IMF where the ...
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147
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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 ...
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Unknown symbol/expression in text about adaptive filters (cst)
I am currently reading a chapter about adaptive filters from the Springer Handbook of Speech Processing.
In a formulation of the variable stepsize normalized least mean squares (VSS-NLMS)-algorithm, ...
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92
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Data Adaptive technique
I am doing data analysis. I used the wavelet transform and now I am trying the Hilbert–Huang transform (HHT). In the literature, I read that Hilbert–Huang transform (HHT) is an adaptive technique. I ...
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429
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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) ...
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Noise cancellation using RLS Algorithm [closed]
I am trying to do Noise cancellation using RLS algorithm at a software level, as part of my M.Tech Project work. Here, the error strength is continuously increasing, instead of decreasing as time ...
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1
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135
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Is CMA equalization applicable for OFDM
I have a question regarding the constant modulus algorithm (CMA), as you know it's one of the known algorithms used for blind equalization. The cost function of the CMA is build blindly, it means ...
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How general are adaptive-filtering techniques? [closed]
How often do problems arise that let you use adaptive filters? Unless I am understanding something incorrectly it seems the requirement that the input signal be stationary(or even WSS) is too strong ...
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180
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Block LMS with overlapping blocks
In the Block LMS algorithm, the input is partitioned into nonoverlapping blocks of size $L$ and the filter coefficients are updated once every $L$ samples. Would convergence improve if we used more ...
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75
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Constructing Contour for Star QAM Equalization
I am trying to equalize the 16 Star QAM using known blind channel algorithms such as CMA,MMA,SCA,RCA,IRCA,CXA,SCXA.I now need to contruct a new contour for equalizing the 16 Star QAM.As it is in ...
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395
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RLS Algorithm (Memoryless)
I have been studying the adaptive filters lately and now when I am at RLS (Recursive Least Squar) Algorithm I came across the term used in the weighting function of the RLS called forgetting factor ($\...
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160
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Applications for adaptive and non adaptive histogram equalization
I have a question regarding histogram equalization and adaptive histogram equalization.
In which circumstance would it be preferable to use adaptive histogram equalization over histogram equalization ...
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Is document image binarization a closed research field [closed]
A lot of work has been done in the field of document image binarization. Is it a closed research field or still an interesting challenge area? I am new in the field, and just curious.
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Signal chain for voice calls including adaptive noise cancellation, adaptive echo cancellation, and automatic gain control and their algorithms
I am trying to understand the entire signal chain and all the algorithms associated with adaptive filtering as mentioned in the case above. From my understanding:
Adaptive noise filtering (ANF)- can ...
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854
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Noise cancellation using RLS filter
I am trying to create an adaptive noise canceller using the RLS algorithm. The dsp toolbox from matlab offers the RLS adaptive filter already implemented, so this saved me some trouble.
My goal is to ...
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2
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118
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Stochastic approximation algorithm
The goal is to find the FIR filter coefficients $\mathbf{h} = [5;3]$ with the help of the adaptive FIR filter $\mathbf{w}$ of order $p = 2$.
I have implemented the Stochastic approximation algorithm ...
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Adaptive filtering: Optimum filter length and delay
I'm trying to find the optimum filter length for an Adaptive Filtering, using RLS Algorithm.
I'm using this design:
So the "error" signal is the signal without noise (and that's the signal that I ...
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Regression vector size for prediction, reconstruction and filtration with adaptive filters
I am working with adaptive filters and similar adaptive models (mainly with gradient adaptation) for a few years. I and my colleagues always struggle to find out the correct size of regression vector.
...
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173
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Transient and steady-state analysis for adaptive filter
I have got review for my work saying, that my work (adaptive filter variant) should be analyzed in transient and steady-state before claiming it improves performance.
I have done common (in my ...
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2
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Upsampled input to an Adaptive filter?
I will try to explain the issue I am having as clearly as possible without going into my coding or maths. I have my own and a MATLAB Central implementation pf standard LMS in MATLAB. Fixed step size. ...
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How the Gain Term $ K \left( n \right) $ Is Derived? Why Is It Called Gain?
In "adaptive filter theory" and "advance signal processing and Noise reduction" they have directly come up with the term gain without stating how they got it.
In adaptive filter theory they have ...
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Regarding the choice of cost function in adaptive control - squared error vs absolute error
I did search the question database regarding this question, and although one or two questions came close, they didn't really address my specific question.
In adaptive control based on minimizing ...
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Control theory: how do you initialize input for a model predictive controller?
Although I think this is a pretty popular algorithm, I posted this question on electronics stacksexchange but received no response. I am posting it here to see if there are many signal/control experts ...
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What is usual independence assumptions on adaptive filters
In this paper stands:
The derivation and analysis of NLMS rest upon the usual independence assumptions.
It has a footnote:
The independence assumptions used in the analysis of adaptive filters
...
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Instability Problem in Normalized Least Mean Squares (NLMS) Adaptive Algorithm
I have been used NLMS algorithm to equalize 4x4 MIMO signals, but the bit-error-rate (BER) after equalization is unstable with iterations. I don't know if it is the normal behavior of the adaptive ...
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Are the RLS filter and Kalman filter gradient methods?
I would like to extend my previous question
What is difference between LMS and gradient-descent adaptation?
with this other question.
I found out, that RLS and Kalman filter learning seems to be ...
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What's the Difference Between LMS and Gradient Descent Adaptation?
I found algorithms that seems the same to me, but they are described with different names (in field of adaptive filtering).
For example:
LMS - least-mean-squares seems to be GD - stochastic gradient ...
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423
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Best DSP algoritms for ultrasonic background noise cancellation
I am looking into detection of pressurized gas leaks by means of the broadband hissing sound (white noise) generated from pressurized leaking gas. The instrument will have a broadband microphone ...
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351
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Cost function for adaptive algorithms
I am having little difficulty to understand that why most of the adaptive algorithms use error power or addition of error power as cost function/minimization criterion. I have read that minimization ...
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Estimate $s$ from $y=s+n$
Now I receive $y=s+n$, $s$ is the signal and $n$ is the white guassion noise. Everytime $s$ will be change irregularly, have some methods to get a estimation of $s$ namely $\hat s$?
Namely $s$ is ...
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Modeling ADC in Active Noise Cancellation
I'm tinkering in Matlab with a problem that's very similar to active noise cancellation. In the literature, the secondary path is described as the transfer function from the output of the adaptive ...
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421
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Echo cancellation supporting long delays and without frequency domain processing
AEC algorithms mostly rely on LMS adaptive filtering, i.e. you update FIR filter coefficients then perform the filtering. Theoretically, the FIR must be as long as the maximum echo length you want to ...
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MATLAB : Proper estimation of weights and how to calculate MSE for QPSK signal for Constant Modulus Algorithm
I had asked conceptual Question about Constant Modulus Algorithm. I am implementing the simple steps of the algorithm, as I do not have the cma() built in module.
...
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