Forums Search for: Equalizer
expectations from a DFE ?
inHi, 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
inI 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
inWould 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
inHi, 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
inHi, 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
inHi 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
inHi, 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
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.
inHi 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
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
inHi 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?
inHi 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
inHi 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)
inDear 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
inI 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
inThere 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). Iâm no audiologist but this seems suspicious to me; I donât think having a high threshold is the
Allpass filter
inHallo, 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
inHi 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
inhi 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
inHow 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...