Upsample, Downsample in the DSP audio Processing

Started by Kathy_pdx in comp.dsp6 years ago 14 replies

The audio system sample rate is 192 kbits/s. The DSP audio processing involves the ASIC hardware and DSP processor. Due to the...

The audio system sample rate is 192 kbits/s. The DSP audio processing involves the ASIC hardware and DSP processor. Due to the real-time constrains, the equalizer need be implemented at 16 kbits/s by a DSP processor. The routine way is to first down sample the audio signal to 16 kbits/s, design an equalizer, then apply the equalizer to the audio signal at 16 kbits. Then the equalized audio signal ...


Linar & DFE Equalizer

Started by hisylee in comp.dsp13 years ago 2 replies

Hi guys Now I`m studying the Equalizer I`m coding the linear and dfe EQ but there is no different I don`t know what is wrong can...

Hi guys Now I`m studying the Equalizer I`m coding the linear and dfe EQ but there is no different I don`t know what is wrong can you correct this code or give me some idea %%%%DFE(Training+Direct) vs. Linear%%%% clear all; N=1000; % length of the information sequence K=5; actual_isi=[0.2, -0.15, 1.0, 0.21, 0.03]; sigma=0.01; delta=0.08; %0.08 delta2=0.00008;...


multi sampling frequency filtering

Started by Fred Nach in comp.dsp16 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...


equalizer visualization tools in public domain

Started by Anonymous in comp.dsp15 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.dsp12 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


ML equalizer lower bound

Started by sair...@gmail.com in comp.dsp15 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.


complex valued Equalizer - zero forcing criterion

Started by rifo in comp.dsp14 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...


spectrum analyzer/equalizer

Started by dr.oktopus in comp.dsp11 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


Choose equalizer or channel coding?

Started by mguo in comp.dsp16 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.


interaction between bandpass equalizer and pll

Started by tmoshe in comp.dsp15 years ago 4 replies

Hi, When using the SG algorithm for equalizing, the error signal is computed at the end of the pll. My problem is that the pll cannot be locked...

Hi, When using the SG algorithm for equalizing, the error signal is computed at the end of the pll. My problem is that the pll cannot be locked before the channel is reasonably equalized. Thus, I have a "bootstrap" where the equalizer need phase information(from pll) and the pll need equalized signal in order to work properly. I still have not simulated this situation, so I need your experience...


interaction between bandpass equalizer and pll

Started by tmoshe in comp.dsp15 years ago 1 reply

Hi, When using the SG algorithm for equalizing, the error signal is computed at the end of the pll. My problem is that the pll cannot be locked...

Hi, When using the SG algorithm for equalizing, the error signal is computed at the end of the pll. My problem is that the pll cannot be locked before the channel is reasonably equalized. Thus, I have a "bootstrap" where the equalizer need phase information(from pll) and the pll need equalized signal in order to work properly. I still have not simulated this situation, so I need your experience...


Derotation effects in multipath channel

Started by alberto.fuggetta in comp.dsp11 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 ...


Linear equalizers and similarities

Started by Peter Mairhofer in comp.dsp4 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...


How to design a DFE equalizer?

Started by fl in comp.dsp15 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...


does the equalizer come before the matched filter or after?

Started by bharat pathak in comp.dsp11 years ago 9 replies

I have a basic doubt. Does the equalizer come before the matched filter or after?

I have a basic doubt. Does the equalizer come before the matched filter or after?


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

Started by Anonymous in comp.dsp15 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 ...


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


RTDX Interupt Problem (Probably)

Started by jcockburn in comp.dsp16 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...


MMSE and ZF equalization in OFDM systems

Started by Dan25 in comp.dsp7 years ago 5 replies

Hi, What is the performance difference of MMSE equalizer and ZF equalizer in a OFDM system. I have simulation 3 tap Rayleigh channel for QPSK...

Hi, What is the performance difference of MMSE equalizer and ZF equalizer in a OFDM system. I have simulation 3 tap Rayleigh channel for QPSK ODFM system and found out that both the equalizers give the same performance. But in Single carrier Frequency Domain Equalization, MMSE performs significantly better than ZF. Can anyone please advice me in this regard. Thanks in advance. _...