first tap of equalizer

Started by aamer in comp.dsp13 years ago 1 reply

dear all, I was trying to implement constant modulus algorithm for blind channel equalization. I found that the filter taps of the equalizer...

dear all, I was trying to implement constant modulus algorithm for blind channel equalization. I found that the filter taps of the equalizer are modified according to W(k+1)=W(k)+ mu * conj(x(k)) * e(k) where mu= adaptation size W the filter taps. x(k)= transmitted symbol e(k)= error given by e(k)= y(k) * (b^2 - abs(y(k))^2) where b^2= 13.2 and y(k)= equalized output. my question i...


Equalizer

Started by Tom in comp.dsp13 years ago 13 replies

I have two complex signals (Input and output) of a channel I need to equalize. I can have 2 linear equalizers one for the real part and one for...

I have two complex signals (Input and output) of a channel I need to equalize. I can have 2 linear equalizers one for the real part and one for the imaginary and train them independently or I can use one complex equalizer and train it using the complex signal. My questions are which one is better? Is there any advantage of one on the other or they are equivalent ? Regards Tom ...


equalizer output issue - eqout.jpg (0/1)

Started by Muzaffer Kal in comp.dsp12 years ago 5 replies

Hi everyone, I'm working on an LMS adaptive filter which is behaving in somewhat of an unexpected way. The attached image shows the histogram of...

Hi everyone, I'm working on an LMS adaptive filter which is behaving in somewhat of an unexpected way. The attached image shows the histogram of the equalizer output after convergence; my slicer thresholds are at 0.5 and -0.5 (ie anything above 0.5 is sliced to 1, anything below -0.5 is sliced to -1 and anything in between is sliced to 0; this is a 3 level code.) Then I use an error generate...


Linear equalizers and similarities

Started by Peter Mairhofer in comp.dsp3 years ago

Hello, The usual setup: Suppose that I can model a channel as FIR filter h such that the received signal is y=h*x+w (*: convolution; x:...

Hello, The usual setup: Suppose that I can model a channel as FIR filter h such that the received signal is y=h*x+w (*: convolution; x: transmitted signal; w: measurement noise). The goal is to find an FIR equalizer g such that xhat=g*y is close to x. Writing x/y as vectors, the relation can be written as y=Hx+w. The equalizer xhat=Gzf y with Gzf = (H^T H)^-1 H^T is called the Z...


Parametric equalizer

Started by Kuba in comp.dsp15 years ago 1 reply

Hi everybody, I am new in this group and I have a problem. I have a project that requires a parametric equalizer on TI C6713. Can anyone help...

Hi everybody, I am new in this group and I have a problem. I have a project that requires a parametric equalizer on TI C6713. Can anyone help me with this? I have a little experience with programming TI ( I have made my past projects with Motorola 56300). Do You have some links that can help me? Maybe someone has links to good sites describing " How to start programming TI with CCS " ...


TPS Decoding in DVB T/H

Started by Anonymous in comp.dsp14 years ago

Hallo, everyone I have just decoded the TPS in DVB-T/H before and after the channel equaqlizer. The result by me shows, TPS Decoding before...

Hallo, everyone I have just decoded the TPS in DVB-T/H before and after the channel equaqlizer. The result by me shows, TPS Decoding before the channel eqalizer is more robust as after the Channel Equalizer even by TU-6 or AWGN channel. Can somebody tell me the reason? My Channel Equalizer works fine for the data tone. thanks a lot jjyy


TPS Decoding in DVB T/H

Started by Anonymous in comp.dsp14 years ago 2 replies

Hallo, everyone I have just decoded the TPS in DVB-T/H before and after the channel equaqlizer. The result by me shows, TPS Decoding before...

Hallo, everyone I have just decoded the TPS in DVB-T/H before and after the channel equaqlizer. The result by me shows, TPS Decoding before the channel eqalizer is more robust as after the Channel Equalizer even by TU-6 or AWGN channel. Can somebody tell me the reason? My Channel Equalizer works fine for the data tone. thans a lot jjyy


Derotation effects in multipath channel

Started by alberto.fuggetta in comp.dsp10 years ago 2 replies

Hi, I'm simulating a DFE equalizer in Matlab for a MSK modulated signal. The channel I'm testing is Ricean with max doppler shift of 50 Hz. I...

Hi, I'm simulating a DFE equalizer in Matlab for a MSK modulated signal. The channel I'm testing is Ricean with max doppler shift of 50 Hz. I noticed that the performance of the DFE deeply improves if I apply the derotation before sending the samples to the equalizer. Has anybody ever observed the same behavior? Does any theoretical explanation for this phenomenon exist? Thanks Alberto ...


multi sampling frequency filtering

Started by Fred Nach in comp.dsp15 years ago 1 reply

Hi all ! I'm trying to design a digital graphical equalizer (8 bands), which can deal with many samlping frequency... so it should be able to...

Hi all ! I'm trying to design a digital graphical equalizer (8 bands), which can deal with many samlping frequency... so it should be able to equalize let say either in 48k, 44.1k, 22k, 32k... in the same way. So my question is ... do I have to design an equalizer for each sampling frequency or is there a good (and memory coefficent table saving) trick ? I'm think of maybe designing t...


How to design a DFE equalizer?

Started by fl in comp.dsp14 years ago

Hi, I want to know how to design a DFE equalizer. In some text books, it gives the formular but I don't know how to calculate the...

Hi, I want to know how to design a DFE equalizer. In some text books, it gives the formular but I don't know how to calculate the correlation and cross correlation matrix. On the other hand, some material gives formular when one have the received training samples. My situation is that I know the channel impulse response (of course, this is a assumption). How to design a DFE with the criterio...


ML equalizer lower bound

Started by sair...@gmail.com in comp.dsp14 years ago 1 reply

Hi, I would like to derive the ML equalizer lower bound for frequency selective fading channels , when the channel is modeled as FIR...

Hi, I would like to derive the ML equalizer lower bound for frequency selective fading channels , when the channel is modeled as FIR tapped delay line with complex Gaussin random variables as channel tap gains. I am not sure, whether there exisists a bound for this? Any help in this is highly appreciated. Best Regards, -SaiRamesh.


equalizer visualization tools in public domain

Started by Anonymous in comp.dsp14 years ago

Are there any good c/c++ music (external mic input) equalizer and/or music visualization applications (with source code) in public domain? I am...

Are there any good c/c++ music (external mic input) equalizer and/or music visualization applications (with source code) in public domain? I am looking for some basic functionality as a starting point. Thanks, Ben


group delay equalizer

Started by bharat pathak in comp.dsp11 years ago 22 replies

Hi, Matlab has a function called iirgrpdelay which helps in designing iir group delay equalizer filters. Any idea as to how this...

Hi, Matlab has a function called iirgrpdelay which helps in designing iir group delay equalizer filters. Any idea as to how this function can be re-written for people who are not using matlab? Bharat Pathak


complex valued Equalizer - zero forcing criterion

Started by rifo in comp.dsp13 years ago 11 replies

Dear all, For demonstrating the effect of a multipath channel on a wireless comm. system, I am trying to implement an equalizer working...

Dear all, For demonstrating the effect of a multipath channel on a wireless comm. system, I am trying to implement an equalizer working according to Zero-Forcing criterion. However I think I have some vaque points in the theory so I would be most happy if you can advice/correct me on the below issue. What I planned to do was to find out the transfer function of my multipath filter (I assum...


Choose equalizer or channel coding?

Started by mguo in comp.dsp15 years ago 4 replies

This is a very nice forum and a lot of knowledgeable people here. I have a question don't know if any experts can share some thoughts on. If...

This is a very nice forum and a lot of knowledgeable people here. I have a question don't know if any experts can share some thoughts on. If you are using GMSK over a wireless channel, and if you can choose only one feature to improve your system sensitivety, will you choose adaptive equalizer or channel coding? Which provides more benefit? GSM has both while DECT seems to have none.


spectrum analyzer/equalizer

Started by dr.oktopus in comp.dsp10 years ago 2 replies

Hello, I am searching for good references on programming a spectrum analyzer/equalizer like those seen on most music players. I read about the...

Hello, I am searching for good references on programming a spectrum analyzer/equalizer like those seen on most music players. I read about the fast fourier transform, however the complete task seems full of details that I ignore. I tried to look inside opensource players (xmms), but perhaps a good overview of all is better to begin with. Thanks, wily


Equalizers implemented in GSM receivers

Started by Dan25 in comp.dsp7 years ago 6 replies

Hi All, I need some specific information on channel equalizer implementations of practical GSM receivers. I assume time domain equalizers are...

Hi All, I need some specific information on channel equalizer implementations of practical GSM receivers. I assume time domain equalizers are used in GSM phones, but I would like to the equalizer algorithms and training algorithms and convergence algorithms used by them. I highly appreciate if anyone can share his/her experience on this regard. All the references are highly appreciated. ...


RTDX Interupt Problem (Probably)

Started by jcockburn in comp.dsp15 years ago 1 reply

Hi, I'm doing a student project and I have made a simple graphic equalizer using a c6711 DSK. I am trying to write a host application to put a...

Hi, I'm doing a student project and I have made a simple graphic equalizer using a c6711 DSK. I am trying to write a host application to put a pretty user interface on the equalizer using RTDX (JTAG, not HSRTDX) to send the positions of several sliders to the DSK. I have successfully written the host program, and a corresponding target application that reads the values that are written and p...


Interpolated Constant-Q Equalizer

Started by in comp.dsp13 years ago 36 replies

Hello, We are implementing DSP based 31 band 1/3 octave audio graphic equalizer on programmabele DSP. The customer specifications demand...

Hello, We are implementing DSP based 31 band 1/3 octave audio graphic equalizer on programmabele DSP. The customer specifications demand for an Interpolated Constant - Q topology. For the implementation we are basing our design on Rane's Dennis Bohn paper on AES ("Constant-Q Graphic Equalizers", JAES Volume 34 Number 9 pp. 611-626; September 1986). Although the topologies suggested on the ...


Does noise enhancement affect Bipolar/QPSK data (since only the sign counts)

Started by Anonymous in comp.dsp14 years ago 5 replies

(My question is at the bottom) ======= POST FROM STEFFEN LAST JULY ON COMP. DSP ====== Regarding the noise enhancement after applying the...

(My question is at the bottom) ======= POST FROM STEFFEN LAST JULY ON COMP. DSP ====== Regarding the noise enhancement after applying the linear zero-forcing equalizer I've found some explanation in "digital communications, Proakis, 4.Ed, chap.10, p.621" :o). Proakis says:"...the performance of the equalizer is poor whenever the folded spectral characteristic possesses nulls or takes on ...