Questions tagged [equalization]
The equalization tag has no usage guidance.
101
questions
1
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1answer
41 views
Output of Zero-forcing equalizer doesn't match theoretical calculations
Let's say I have a sequence $x[n]$ (signal) and perform convolution with another sequence $h[n]$ (channel), so:
$$
y[n] = h[n]*x[n] = \sum_{k}{h[k]x[n-k]} \leftrightarrow Y(z) = H(z)X(z)
$$
I'm ...
0
votes
0answers
33 views
Types of equalizers
I can't get my mind around the different types of equalizers and the difference between some of them. I've been looking at different books unsuccessfully.
So far, I have Wikipedia's list and this ...
2
votes
4answers
91 views
What Information Is Lost by Histogram Equalization?
I cannot think of a way to restore an original image after histogram equalization. But this latter seems to "enhance" (= increase contrast of) the image's details. What information is then lost by ...
1
vote
1answer
18 views
Question about image equalization
Let $f$ be an $N \times M$-image and suppose that $g$ is its equalization.
Question - Why the equalization does not change the objects, why a car on $f$ does not convert into a bus on $g$?. It is ...
0
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1answer
77 views
On the signal recovery in OFDM after estimation
Given a modulated signal X which is transmitted based on OFDM with N = 256 sub-carriers through channel ...
0
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0answers
35 views
Clip wav by PSD
I have the following two things.
sequence_1: Sound file in the wave format.
PSD_1: Some PSD (Power Spectral Density).
I want that the PSD(sequence_1) < PSD_1 for all indices.
How I think about ...
1
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0answers
19 views
Converting the equalizer coefficients from VSA at 2 sample/Symbol to 1.5 sample/Symbol
I was looking for some feedback on conversion of equalizer/filter coefficients at different sampler rate.
Problem Statement:
We have built a transmitter system whose output is at 1.5 sample/symbol (...
0
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0answers
14 views
Is the Channel Equalization corrects Carrier Frequency Offset (CFO) in signal?
As we know channel equalization is used for restoring the distortion ocured in signal. Hence, can we say the Carrier Frequency Offset (CFO) is being corrected and restored the actual signal.
2
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0answers
17 views
How to exploit auditory masking to boost intelligibility
I am currently working on a dynamic equalizer to improve a synthesized voice's intelligibility in noisy environments.
The current implementation of my algorithm simply applies a parametric EQ to the ...
0
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0answers
21 views
Hisotgram equalisation error, help with my code
Iam working on implenting a histogram equalisation of an image without using inbuilt functions specifcally imhist and histeq, I have, for the most part understood what do during a histogram ...
0
votes
0answers
41 views
Correlation function in RLS-based equalization
In the Recursive Least Square (RLS) algorithm , the correction applied to the previous estimate consist of the product of two factors: the prior information error and the kalman gain vector, which ...
0
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0answers
31 views
Training Fractionally Spaced Channel Estimator and Equalizer
If you are attempting least squares channel estimation with a fractionally spaced channel estimator, do you want the training sequence to also be fractionally spaced or symbol spaced? It looks like ...
0
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0answers
66 views
Digital Communications block diagram question
I am new to digital communications and trying to understand the basic underlying concepts of digital comm systems. So far , studying the course , I have some questions which if anyone can answer would ...
0
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0answers
15 views
Amplifying the difference of luminance between pixels of color images?
I'm doing some research on digital watermarking and came across an article that embeds QR codes on mostly grayscale images and the extraction part for color images is quite confusing the article ...
1
vote
0answers
97 views
The Definition of Q Factor by an Equation and How to Graph
I am currently building an EQ in an music app, and it's relatively simple:
6 bands of fixed center frequency, and a Q knob to control the Q of all bands, because we do not currently have space for ...
0
votes
1answer
63 views
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 ...
1
vote
1answer
74 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 ...
3
votes
1answer
237 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!
0
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1answer
37 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 ...
0
votes
1answer
34 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 ...
0
votes
1answer
80 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.
0
votes
1answer
46 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 ...
0
votes
1answer
46 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 ...
1
vote
1answer
280 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 ...
1
vote
1answer
43 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
votes
1answer
65 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 ...
4
votes
1answer
155 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 ...
0
votes
2answers
304 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....
1
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0answers
214 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 ...
0
votes
1answer
239 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
1
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0answers
145 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 ...
0
votes
0answers
71 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 ...
1
vote
1answer
958 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 ...
0
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0answers
60 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?
1
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0answers
43 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 ...
1
vote
2answers
83 views
1
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0answers
61 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
votes
1answer
220 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 ...
1
vote
0answers
159 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
vote
1answer
254 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 ...
3
votes
2answers
84 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 ...
1
vote
0answers
185 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
vote
1answer
95 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
vote
1answer
308 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 ...
2
votes
2answers
273 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
vote
1answer
224 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
votes
1answer
160 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
votes
1answer
463 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 ...
4
votes
1answer
614 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 utilities a Wiener-like approach, ie it converges to the optimal (wiener) solution.
I ...
0
votes
1answer
425 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 ...
