Questions tagged [equalization]
The equalization tag has no usage guidance.
127
questions
2
votes
1answer
56 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
78 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
244 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
639 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
315 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
309 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
vote
0answers
178 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
88 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 ...
2
votes
1answer
2k 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
votes
0answers
80 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
59 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
85 views
1
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0answers
91 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
258 views
Model Validation After Estimation for System Identification Task (Assistance with MATLAB Code)
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
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0answers
189 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
325 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
114 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
301 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
121 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
366 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
290 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
380 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
226 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
588 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
1k 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
667 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
vote
1answer
177 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 ...
0
votes
0answers
100 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
votes
2answers
872 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
votes
1answer
107 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
votes
1answer
246 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
votes
1answer
113 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
votes
2answers
146 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 ...
1
vote
2answers
2k 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 ...
2
votes
2answers
1k views
Parametric EQ vs multiple bandpass filters
Will filtering a signal through multiple bandpass filters, where each filter is passed the complete signal, and then combining the output have the same result as a parametric EQ?
What if the signal ...
1
vote
0answers
165 views
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 ...
1
vote
1answer
317 views
Why do the OFDM training (and payload) symbols have silent sub-carriers (aka virtual carriers)?
I am examining an OFDM signal.
Training symbol:
The first two OFDM symbols are training symbols, they are 2PSK modulated (within the subcarriers).
In the first OFDM symbol the $(0+18N)^{\rm th}$ ...
2
votes
2answers
338 views
Fractional spaced equalizer + timing (clock) recovery
I am trying to figure out how timing recovery is used after equalization (or, being more correct, when the equalizer is in the timing recovery loop), having a T/2 fractional spaced equalizer and using ...
0
votes
2answers
109 views
MP3 equalization
I made an equalizer using eq10q filters. Now I want to use my equalizer for music equalization and make my own music player. So I have some doubts:
If I want to equalize MP3 files, do I have to ...
1
vote
1answer
109 views
Histogram Equalization
I am reading the etext on Digital Image Processing by Gonzalez and under the section on Histogram Equalization, an equation which is apparently basic is shown. I have no clue what the equation means ...
1
vote
1answer
936 views
Given an FIR filter coefficients, how can I find coefficients of its equalizer filter?
I have an N-tap direct form complex FIR filter with known coefficients [c0 c1 .. cn]. I want to find the coefficients of its equalizer filter which when cascaded ...
6
votes
2answers
599 views
Why are equalizers moving average model (FIR)
Let the equalizer coefficients obtained, say $w$ and the input to the equalizer is $y$ that is a noise corrupted received signal, $rx$ then the equalized signal, which is the output of the FIR based ...
4
votes
1answer
3k views
Design of equalizer for wireless communication
I am having difficulty in trying to understand the working mechanism of an equalizer. Please correct me where wrong.
Mechanism of an Equalizer - The purpose of an equalizer is to reduce intersymbol ...
4
votes
1answer
787 views
Matlab: What should be the BER performance for BPSK using Constant Modulus Algorithm equalizer
I need help in plotting the Bit error curve or the symbol error curve for BPSK modulation scheme for varying Signal to Noise ratios or Eb/N0. The plot should show the simulated versus the theoretical ...
1
vote
1answer
188 views
Equalization knowing the Channel State Information
I am trying to simulate a simple communication system using channel estimation. I was able to estimate the channel response using the Least Squares channel estimator, and it is working properly (...
3
votes
2answers
3k views
Which filter for an audio equalizer
I’m new to DSP and I have to do an audio equalizer in c++.
I did a lot of research about it and tried some stuff in the last month, but I’m a little overwhelmed with all those informations and it’s ...
2
votes
1answer
182 views
Help in deriving the update rule for equalizer
Considering an FIR system excited by an input $s_n$. If the input is derived from a mapping, and a +1/-1 BPSK signal is derived. Considering the Constant Modulus Algorithm (CMA). The channel is ...
2
votes
1answer
7k views
Use of equalizers in communication systems for Intersymbol Interference
In communication systems with high data rates, Intersymbol Interference (ISI) is a major problem (ISI).
I have read in books that one way to combat this problem is to use time domain equalizers (ZF, ...
3
votes
1answer
2k views
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.
...
1
vote
2answers
3k views
Decibels conversion into amplitude ratio
I want to convert db into amplitude ratio.
I did some research but I only found online convertor, and I don't understand what's on Wikipedia very well...
Here is a little of backstory :
I am a ...
