Normalizing Histogram

Started by cpshah99 in comp.dsp11 years ago 3 replies

Dear All I am trying to plot histogram of the o/p of equalizer. As the o/p is complex I will have to plot histogram of real and imaginary...

Dear All I am trying to plot histogram of the o/p of equalizer. As the o/p is complex I will have to plot histogram of real and imaginary part separately. I know it is straight forward in matlab, but the problem is how to normalize y-axis. The modulation I am using is 4-QAM. As this will be bimodal distribution around +1 and -1, I am thinking to do following: 1. find std deviation (\sigma...


about IIR Filter implementation...

Started by zeugnim in comp.dsp13 years ago 2 replies

hi, This is my first filter implementation and is made in Scilab, also the design of the 3ord Chebyshev Type I IIR Filter (with the iir...

hi, This is my first filter implementation and is made in Scilab, also the design of the 3ord Chebyshev Type I IIR Filter (with the iir function). I actually have 3 filters, so i can use them as an equalizer for an audio application. I´m using Direct Form I Realization. Since I have to implement this on a 24bit Fixed-Point DSP I had to scale my coefficients by a factor of 256 (same as shifting...


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...


How are variable filters implemented?

Started by Matti Viljamaa in comp.dsp4 years ago 52 replies

How are filters that have their cutoff and e.g. Q variable (such as in a typical parametric equalizer) done? Does this mean that the filter...

How are filters that have their cutoff and e.g. Q variable (such as in a typical parametric equalizer) done? Does this mean that the filter coefficients are recalculated (i.e. the filter is redesigned) every time the parameters are changed? What kind of other design considerations are involved (such as computational efficiency)? What about "smooth parameter changes", is it interpolation (and...


SPDIF EQ

Started by Dirk Bruere at NeoPax in comp.dsp11 years ago 7 replies

Does anyone do a s/w 3rd octave equalizer that will work on a stereo (non dolby etc) SPDIF output (from a mobo or soundcard)? --...

Does anyone do a s/w 3rd octave equalizer that will work on a stereo (non dolby etc) SPDIF output (from a mobo or soundcard)? -- Dirk http://www.transcendence.me.uk/ - Transcendence UK http://www.theconsensus.org/ - A UK political party http://www.blogtalkradio.com/onetribe - Occult Talk Show


Equalization in OFDM

Started by prabin in comp.dsp14 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...


MAP vs MLSE

Started by bitterbutter in comp.dsp13 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 ...


MLSE tutorial

Started by sl2096 in comp.dsp13 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...


adaptive equalization benefit

Started by mguo in comp.dsp14 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...


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


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...


estimation of autocorrelation matrix or eigenvalue spread.

Started by mk in comp.dsp14 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...


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


Cable Equalizer

Started by Guy Eschemann in comp.dsp11 years ago 14 replies

I'm looking for some inspiration on the following problem: I want to transmit a signal consisting of 8 QPSK-Modulated carriers over a coaxial...

I'm looking for some inspiration on the following problem: I want to transmit a signal consisting of 8 QPSK-Modulated carriers over a coaxial cable, in the frequency range of 1 to 10 MHz. Since the cable has a frequency-dependent attenuation (e.g. 1dB/100m@1MHz, 3dB/ 100m@10 MHz), I need to somehow compensate for this at the receiver before it is forwarded to an optical transmitter. Sinc...


equalization of 'non-continuous' sample

Started by cl7teckie in comp.dsp11 years ago 2 replies

I am trying to build a 'non-continuous' 12-tap FFE (LMS Blind) equalizer in software, hoping to remove to some extent group delay in a satellite...

I am trying to build a 'non-continuous' 12-tap FFE (LMS Blind) equalizer in software, hoping to remove to some extent group delay in a satellite link. I am doing in software, as I am ONLY keen to know the SNR after equalization. The reading are in chunks of 512 x I/Q samples. Technically, does this even work, due to the fact that it is non-continuous. I do not need a perfect system, just some ...


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


BiQuad frequency response for visualisation

Started by jungledmnc in comp.dsp12 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...


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. ...


Filters coefficients in symbol spaced DFE

Started by alberto.fuggetta in comp.dsp10 years ago 9 replies

Hi, I'm trying to equalize a channel with sever multipath using a DFE (12,12) with LMS adaption algorithm. The relative power of the replicas...

Hi, I'm trying to equalize a channel with sever multipath using a DFE (12,12) with LMS adaption algorithm. The relative power of the replicas are quite high w.r.t the main path. (max -4 dB). The equalizer is catastrophic. From the learning curve analysis I can observe that the error is still high after processing the training sequence. Morover, the forward filter coefficients are very small ...


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

Started by Peter Mairhofer in comp.dsp6 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...