expectations from a DFE ?

Started by mk in comp.dsp15 years ago 3 replies

Hi, I've been experimenting with adaptive filters for channel equalization and I have a problem with decision feedback case. Initially I...

Hi, I've been experimenting with adaptive filters for channel equalization and I have a problem with decision feedback case. Initially I started with a T/2 fractional linear equalizer adapted with LMS and then converted this to delayed LMS with two delays. I am currently not adding any noise just trying to compensate for the ISI generated by the channel although there is quantization error a...


Calibrating speakers

Started by Michel Rouzic in comp.dsp15 years ago 20 replies

I just got a new set of 2.1 speaker for my PC for christmas, my main problem with it is that it outputs a very altered sound, mostly the bass,...

I just got a new set of 2.1 speaker for my PC for christmas, my main problem with it is that it outputs a very altered sound, mostly the bass, they are way too loud. I firstly thought it would be easy fixing that with some software equalizer but no, the sound is still very weird. I thought about playing a delta function through my speakers and record it with a microphone to look at the fre...


MLSE tutorial

Started by sl2096 in comp.dsp14 years ago 3 replies

Would some one be able to suggest a good tutorial or explanation of a general implementation for a 4 or 8 state MLSE equalizer for GSM ?...

Would some one be able to suggest a good tutorial or explanation of a general implementation for a 4 or 8 state MLSE equalizer for GSM ? I understand the theory, but would like an explanation of how, for a specific case/example, locations on a constellation are assigned to states and the best way to compute metrics. Preferably, something with illustrations/trellis diagrams would be nice. Thank you...


Equalization in non-coherent systems

Started by Dan25 in comp.dsp7 years ago 4 replies

Hi, I have a general about the usage of equalization for non-coherent systems. I'm considering Differential PSK for a single carrier SISO...

Hi, I have a general about the usage of equalization for non-coherent systems. I'm considering Differential PSK for a single carrier SISO system. I consider different channels with different no., of taps. But I'm not sure what type of equalizer should be used for a such a system. Thanks. _____________________________ Posted through www.DSPRelated.com


Equalization for FH-4FSK system

Started by furqee in comp.dsp13 years ago 4 replies

Hi, I would like to design use an equalizer for improving the performance of 4fsk-frequency hopping system in rayleigh fading, I ve seen...

Hi, I would like to design use an equalizer for improving the performance of 4fsk-frequency hopping system in rayleigh fading, I ve seen matlab functions but they all are for linear modulations or is there any function for non linear modulations??. Can any one please guide me on this issue? Is there any particular technique that is useful for this case?? thanks


Fixed-point MMSE

Started by Anonymous in comp.dsp14 years ago 1 reply

Hi all, Can anybody provide me a fixed-point implementation (matlab, c/c+ +,... ) of the MMSE equalizer? Thanks

Hi all, Can anybody provide me a fixed-point implementation (matlab, c/c+ +,... ) of the MMSE equalizer? Thanks


Stereo audio and Equalizer

Started by snigdha in comp.dsp15 years ago 10 replies

Hi, I am doing my study on graphic and parametric equalizers. I read through some of the previous posts on this site and was really helpful....

Hi, I am doing my study on graphic and parametric equalizers. I read through some of the previous posts on this site and was really helpful. I have one small question though. When I am presented with a stereo audio signal, would it be advisable for me to process the two channels using two separate IIR filter bands? Or just assuming the data to be continuous, can I just use one filter? Th...


Equalization in OFDM

Started by prabin in comp.dsp15 years ago

Hi guys, I was doing the simulations for the multitap frequency domain equalization for multicarrier system (DMT based). It seems though...

Hi guys, I was doing the simulations for the multitap frequency domain equalization for multicarrier system (DMT based). It seems though the at the band edges (First few tones and last few tones) higher performance can be achieved if we use higher number of equalizer taps. Can you people please suggest me any reasons why that happens or at least guide me to any publication that might hel...


estimation of autocorrelation matrix or eigenvalue spread.

Started by mk in comp.dsp15 years ago 12 replies

Hi everyone, I am experimenting with some equalization schemes and to judge the performance, I need to estimate the eigenvalue spread of the...

Hi everyone, I am experimenting with some equalization schemes and to judge the performance, I need to estimate the eigenvalue spread of the input to the equalizer. Currently I am working with a single input stream of many thousands of samples, and I am assuming that my data is more or less uniformly distributed. To get the eigenvalues, I generate R = Sum( x[k]*x[k]T) where x[k] is a vector...


equalizer in matlab

Started by Peter Simpson in comp.dsp11 years ago

It seems that the training symbols have to use the same modulation as the data symbols. Is there any way that I can use different modulations? ...

It seems that the training symbols have to use the same modulation as the data symbols. Is there any way that I can use different modulations? say QPSK for training and 16QAM for data. I tried equalizing the two parts separately with a constellation change in between. The shape of the equalized constellation seems correct, but it is compressed. Of course the demodulation result is wrong. ...


BiQuad frequency response for visualisation

Started by jungledmnc in comp.dsp13 years ago 14 replies

Hi there, I'm trying to make a simple parametrical equalizer using the Audio-eq-cookbook (like everyone else :-)). I use it on audio signal...

Hi there, I'm trying to make a simple parametrical equalizer using the Audio-eq-cookbook (like everyone else :-)). I use it on audio signal and need to visualise resulting frequency response. E.g. peak filter should be painted as a hat-style curve. The problem is, that when I use the attached transport function H(z) the result is pretty different. It seems, that it modifies even frequencies it sh...


Where do the errors come from in a simple Simulink model?

Started by Peter Mairhofer in comp.dsp7 years ago 17 replies

Hi all, Thanks for all who replied to "Typical error level in RF systems". Based on that thread I started from scratch a *simple* I/Q...

Hi all, Thanks for all who replied to "Typical error level in RF systems". Based on that thread I started from scratch a *simple* I/Q transceiver in Simulink and I am not able to get more than about -41 dB NMSE. Ridiculous. If I add the proposed equalizer (numer of taps doesn't matter) I can get up to -47 dB. Not great either. The model is very easy: http://snag.gy/6aXXm.jpg A 20 MH...


Help Needed Regarding Project Graphical Equaliser

Started by singla in comp.dsp14 years ago 2 replies

Hi everyone I m B-tech final year student i m trying to implement graphical equalizer (real time) with TMS320C6711 kit. (Final Year Project) I...

Hi everyone I m B-tech final year student i m trying to implement graphical equalizer (real time) with TMS320C6711 kit. (Final Year Project) I wanna know that 1)Is there any way to introduce adaptive signal processing to it? 2)also ,is there any standard algo to be followed for the task? I will really appreciate any kind of inputs in this regard Thank You


Filters - Maximizing Quality (Structures and Scaling)

Started by davidross in comp.dsp15 years ago 10 replies

Dear List, I was wondering if anyone could offer some advice on what i can do to maximize the quality of my filters. I have developed a...

Dear List, I was wondering if anyone could offer some advice on what i can do to maximize the quality of my filters. I have developed a Parametric Equalizer with 10 bands (for audio). I would like the EQ to sound as good as possible. I am currently implementing the structure as a second order Direct Form. Would it be worthwhile converting this structure over to a lattice ladder structure - I...


Explaining how this filter is working

Started by wijesijp in comp.dsp11 years ago 5 replies

I am building a simple equalizer type audio application and I found following filter online http://musicdsp.org/files/CFxRbjFilter.h The...

I am building a simple equalizer type audio application and I found following filter online http://musicdsp.org/files/CFxRbjFilter.h The application is working but now I need to modify this filter. I am new to DSP and I have a hard time figuring it out. Can anyone explain how this filter is working?


Threshold of hearing compensation

Started by Anonymous in comp.dsp2 years ago 5 replies

There are several new consumer headphone products on the market that allow you to measure your threshold of hearing using an app on your phone and...

There are several new consumer headphone products on the market that allow you to measure your threshold of hearing using an app on your phone and then auto-adjust an equalizer to boost the areas where your threshold is high (indicating hearing loss at those frequencies). I’m no audiologist but this seems suspicious to me; I don’t think having a high threshold is the


Allpass filter

Started by Kuba in comp.dsp16 years ago 4 replies

Hallo, I'm a student and I'm makins an audio device. I have to make a allpass filter or lowpass and highpass, one after another. The point...

Hallo, I'm a student and I'm makins an audio device. I have to make a allpass filter or lowpass and highpass, one after another. The point is that i have to cutt the audio band at about 20Hz and at about 20kHz to get good signal parametres before parametric equalizer. Do You have some sugestions what kind of filters would be best in this case(IIR or FIR and what kind)? It will be im...


MAP vs MLSE

Started by bitterbutter in comp.dsp14 years ago 3 replies

Hi guys, I'm currently doing my literature review on both types of equalization. Based on what I understand, both have comparable performance...

Hi guys, I'm currently doing my literature review on both types of equalization. Based on what I understand, both have comparable performance but use different approach; MLSE: sequence detection while MAP symbol by symbol detection. Since both relatively similar, how can we choose which type of equalizer is suitable to combat ISI? Responds pointing to publications and articles are very much ...


match match match

Started by vimmi in comp.dsp12 years ago 2 replies

hi everyone, iam feeling shy to ask such a small question to the great scholars,but i must in order to complete my project.Could you please...

hi everyone, iam feeling shy to ask such a small question to the great scholars,but i must in order to complete my project.Could you please suggest me any reference for finding information about 1.how to design a matched filter to detect a PAM signal. 2.Is it possible to replace an equalizer with matched filter? **I will be more thankful to you if u could give the answers as quickly as possib...


adaptive equalization benefit

Started by mguo in comp.dsp15 years ago 4 replies

How much benefit can adaptive equalization really get you in a packet transmission system over multipath channel? Since one will need to...

How much benefit can adaptive equalization really get you in a packet transmission system over multipath channel? Since one will need to do synchronization before training the equalizer, it seems to me that synch will be the first one to fail most of the time if ISI is really serious. So that means you must have a synchronization scheme that can deal with serious ISI first. Or you will have to...