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40 views

Where in the signal chain is Channel Equalization applied?

I am reading about channel equalization and I am somewhat confused on where in the signal chain channel equalization is normally applied and if it's before or after a correlator detector or matched ...
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1answer
49 views

What is the difference between an equalizer and a channel estimator?

I was wondering what is the difference between channel estimator and channel equalizer? Thanks!
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1answer
23 views

Need information about following channel model

The following research paper is for blind channel equalization and the author has modeled the channel as 7 tap weights https://ieeexplore.ieee.org/document/1096877 On page 3 it has shown the ...
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1answer
23 views

Equalizing a temporal sound signal with a convolution

This question is more or less the following of a previous question. The aim is to equalize some sounds signals. By equalizing, I mean increasing or decreasing some frequency ranges, a bit like an ...
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0answers
23 views

blind channel estimation using EM implementation

I would like to implement EM for blind channel estimation. The algorithm is briefly described in this paper, under the section "EM for blind channel identification". I'd like to derive the algorithm ...
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1answer
30 views

Inter-Symbol Interference (ISI) channels

Is there any open and free data-set for digital ISI channels? I want to have a variety of ISI channels' taps, such as $h[k]$ here. Especially looking for BPSK channels.
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1answer
34 views

Is the Channel shortening similar to Time domain Equalizer (TEQ)

I used to read about Time domain equalizer (TEQ) in many lectures, i.e here , But in many other papers, that's called Channel shortening i.e here . However, in the a two above links, the cost ...
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1answer
41 views

how to set Equalizer's coefficient using generalized eigenvector.

In that paper https://jwcn-eurasipjournals.springeropen.com/articles/10.1186/1687-1499-2012-72 .. Equation 3, $J(w) = w^HBw/w^HCw$ .. $B$ and $C$ are matrices, $w$ the filter coefficients vector ...
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0answers
12 views

Changing BCJR algorithm to work on all trellis states

I am using the BCJR algorithm for channel equalization (simple ISI channel + AWGN). The algorithm assumes that zeros are transmitted in the beginning and in the end, but I would like to change it not ...
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0answers
24 views

Generating values of EQ presets

I am using this project in Rpi - bmc0/dsp It allows to set various effects and DSP setting to the entire audio stream of the device. I wanted to get some common preset values like Pop, Dance, Rock, ...
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1answer
60 views

estimate the impulse response after equalization

I want to estimate the impulse response of the channel at the receiver. Assuming some arbitrary impulse response: h=[1 0.2 -0.4 0.0 0.6]. Once the equalizer is ...
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1answer
30 views

BER performance of fractional equalizers for colored noise

I am trying to compare the BER performance of fractional and symbol spaced equalizers for channel equalization in colored noise scenario. I have found from simulation that for positively correlated ...
0
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1answer
52 views

What's the difference between Channel shortening and time-domain equalizer

I'm asking about the difference about channel shortening and time-domain equalization. I have checked on-line and tried to get something clear but I couldn't. What I found is that channel shortening ...
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0answers
29 views

Implementing Fractionally Spaced Equalizer

I have been searching for robust algorithm that can be implemented for avoiding the ISI (Inter-Symbol interference), I came across two types of channel equalizations are there. One is data Aided (...
4
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1answer
63 views

What is the difference between pulse shaping and equalizers when used to cancel Inter-symbol Interference (ISI)?

According to Nyquist, to transmit R symbols/sec without ISI, the minimum bandwidth required is R/2 Hz, and the sinc pulse shape satisfies this condition. If we use equalizers instead of pulse ...
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2answers
82 views

Inter Symbol Interference (ISI) / Equalization in Digital Signal Processing

I am studying the OFDM system and before to start I have decided to study the main concepts of modulation. And I have spent yet a lot of time to understand the concept of an equalization to reduce ISI....
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0answers
66 views

Blind equalization with constant modulus algorithm in GNU Radio

I'm currently simulating the effect of multitap channel on BPSK as well as its remedy i.e. equalization. The modem is expected to work with satellite TT&C transponder. The communication channel ...
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0answers
18 views

Initial weighted taps for MMSE equalizer

I have a question regarding the tap weights calculation for a MMSE equalizer. In order to calculate the tap weights one needs to know the cross-correlation vector between the taps matrix and the ...
0
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1answer
76 views

how can I generate SIMO underwater acoustic channel

I'm working in underwater acoustic channel, then I need to generate SIMO channel to use it for simulation in MATLAB, how can I generate SIMO channel? thank you
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0answers
92 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 ...
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0answers
57 views

Satellite receiver suite

I'm in the process of implementing a general purpose baseband system for modulation schemes (Linear + CPM) commonly used satellite and deep-space TT&C as shown in the functional flow block diagram ...
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0answers
36 views

Need some help in plotting ISI and MSE of the outputs from adaptive equalizer

I am implementing a blind adaptive equalizer using different algorithms in MATLAB and plotting their residual ISI and Mean Square Error Plots.My plots of residual isi and mse are not in agreement as ...
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1answer
115 views

Precursor ISI - causality violation?

Today, in my lecture on intersymbol interference (ISI), there was a discussion on postcursor ISI, and precursor ISI. Postcursor ISI is caused by the past bits, whereas, precursor ISI is caused by the ...
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0answers
43 views

Best equalizer for a perfect CSI

Assuming a MIMO system and a perfect CSI (the channel matrix is known), what can be the best equalizer? ZF or others?
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0answers
27 views

Need some help in optimization problem in blind channel equalization

Blind Channel Equalization is used to inverse model the channel effect on recieved signal so that the unnecessary noise and ISI is removed from recieved signal constellaion.The most famous algorithm ...
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0answers
35 views

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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2answers
82 views

MATLAB's $\tt dsp.ParametricEQFilter$ bandwidth question

Consider the following code: ...
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0answers
35 views

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 ...
5
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1answer
195 views

Model validation after estimation — system identification — help with an example in Matlab

QUESTION: I want to determine how well the estimated model fits to the future new data. How do I validate the estimated model...what is the procedure? After system identification, how to do model ...
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0answers
108 views

Speaker equalization for white noise

I need a speaker to play broadband white noise for my scientific application. I would like to know whether my relative naive implementation is correct or not. The speakers I use have a large frequency ...
1
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1answer
135 views

Entropy of enhanced image more than the original image

It is said that the entropy of an image is the information that it contains. Let us assume, that the entropy of an image f(x,y) is ...
4
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2answers
63 views

Besides computational costs, is filtering, decimating, then filtering different from just filtering?

Background: I have a variety of BPSK which uses a raised cosine transmitted pulse shape: $$ h(t) = {1 \over 2}\, (1+\cos(\pi t))\, \Pi(t/2) $$ After matched filtering in the receiver, the end result ...
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0answers
92 views

SNR for channel after equalization

Suppose I have a channel described by $h[n]$ or $H(z)$ over which I send a simple PAM2 signal. After the channel AWGN is added. What is the best possible SNR with equalization? As suggested in the ...
1
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1answer
78 views

Determining pulse shape for Viterbi Equalization

I believe I understand well enough how the Viterbi algorithm can reverse the effects of ISI when the combined impulse response (transmit filter, multipath, receive filter) is known. I've read How I ...
1
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1answer
209 views

LMS and delta impulse response- Equalization concepts

I have been reading about equalization and channel estimation in order to apply to my application of estimating trajectory path for a two-wheeled robot. The application is quite similar to ...
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2answers
197 views

Magnetometer coil equalization

I have a search coil magnetometer with two coils, one at each end of a ferromagnetic core of high magnetic permeability: Figure 1. Double search coil magnetometer. (Modified from a drawing CC BY-SA 3....
1
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1answer
125 views

Two-sided impulse response and its inverse in real life

Dear StackExchange gurus, I would like to pose this question from a practical standpoint rather than a theoretical one, although perhaps some context in the latter might come useful. Real-life ...
0
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1answer
80 views

Constant modulus algorithm - performance poor?

The question is based on a research article titled, "Novel Robust Blind Equalizer for QAM Signals Using Iterative Weighted-Least-Mean-Square Algorithm" The Authors have proposed an equalization ...
0
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1answer
321 views

Zigbee Transceiver Using OQPSK Modulation under Fading Channels

I am working on transmitting ECG signal over wireless body area networks. According to IEEE802.15.4 standards , I am using ZigBee transceiver at 2.4 GHZ . Complex baseband equivalent channel model is ...
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0answers
31 views

What are the methods of optimizing the well known Stochastic Gradient Tap Update Algorithm Performance?

As the Stochastic Gradient Algorithm tap update equation is: $$ w[n+1]=w[n]-\mu \bigtriangledown J(w) $$ $w$ are the filter tap weights So what are the methods for optimizing the performance of this ...
1
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1answer
286 views

What Is the Difference between RLS, LMS and Wiener Filter? When Is One Preferred Over Another?

I'm dealing with a channel equalization problem where the channel is modeled as a WSS process. I understand LMS utilises a Wiener-like approach, ie it converges to the optimal (wiener) solution. I ...
0
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1answer
178 views

Fequency Domain Oversampling - decimating when going back to time domain

I'm currently trying to simulate Frequency Domain Equalization, and the effect that over sampling in the frequency domain has on the affect of the equalization. If I understand things correctly this ...
1
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1answer
64 views

spectral factorization method

So I'm trying to figure out a method to do spectral factorization, where we take some function $X(D) = (1+cD)(1+cD^{-1})$. I believe this is used in equaliation I can do this if I just plugging in ...
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0answers
43 views

Help me out in finding the problem in my given MATLAB code of Rectangular Contour Algorithm(RCA)

I am implementing the Rectangular Contour Algorithm (RCA) used for blind channel equalization on 32 Rectangular QAM Signal, polluted with noise and channel effects. It is described in: Khan Q. - ...
5
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2answers
447 views

CMA Equaliser and FSK

I'm looking into equalisation for FSK over HF channels for Digital Voice applications. As a starting point, I am trying to understand the CMA algorithm. I found a nice CMA Matlab example for BPSK in ...
0
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1answer
88 views

How to equalize an ISI channel when the transmitted symbols are unknown?

I am using MATLAB to simulate transmission of binary data sequence, $\mathbf{x}={x_k\in\{+1,-1\}\forall 0\leq k\leq N}$, over an ISI channel whose impulse response $\mathbf{h}=[h_0 h_1 \cdots h_{\mu}]$...
0
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1answer
189 views

Conceptual Question on equalization technique in rayleigh fading channel based on a paper

Question Link http://www.raymaps.com/index.php/theoretical-ber-of-m-qam-in-rayleigh-fading/ gives theoretical expressions for BER in Rayleigh fading channel. Can I use the expression for 64-QAM in ...
0
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1answer
70 views

When and how can multiple EQ filters be merged into one?

As I understand it, it should be possible to merge similar filters, e.g. if I have two shelving filters with the same Q and frequency but different gains, I can just merge them into one by adding the ...
2
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2answers
121 views

Equalizing frequency response in software

I'm playing audio through a speaker which I know to have a non-flat frequency response, with particularly poor response in the low ($<1\textrm{ kHz}$) ranges. My plan to get around this problem is ...
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2answers
818 views

Equalize Speaker using Frequency Response Curve

I have a speaker for which I know the frequency response curve (-5dB at 600Hz, -3dB at 700Hz, ... +5dB at 10kHz). This response curve is not as flat as I would like, and so I want to write a script ...