How to design a graphic equalizer

Started by dingke1980 in comp.dsp15 years ago 6 replies

I am doing a software project about a ten-band graphic equalizer. Is there any solutions about how to design it? Currently, I have the...

I am doing a software project about a ten-band graphic equalizer. Is there any solutions about how to design it? Currently, I have the following ideas: 1.Use FFT, apply different gains to each frequency bin. But for low frequency band like 31.25Hz, 62.5Hz, 125Hz, there are few frequency bins even using large length FFT. The frequency precision is roughly influencing. 2.Use FIR filter bank. D...


How to design a graphic equalizer

Started by dingke1980 in comp.dsp15 years ago 1 reply

I am doing a software project about a ten-band graphic equalizer. Is there any solutions about how to design it? Currently, I have the...

I am doing a software project about a ten-band graphic equalizer. Is there any solutions about how to design it? Currently, I have the following ideas: 1.Use FFT, apply different gains to each frequency bin. But for low frequency band like 31.25Hz, 62.5Hz, 125Hz, there are few frequency bins even using large length FFT. The frequency precision is roughly influencing. 2.Use FIR filter bank....


Linear-phase FIR filter coefficient properties

Started by m26k9 in comp.dsp10 years ago 50 replies

Hello, I have some unclear points about FIR filter coefficients which I would like to get some help on. First, what I want to do is to...

Hello, I have some unclear points about FIR filter coefficients which I would like to get some help on. First, what I want to do is to design a simple pre-equalizer for a DMT system. I have the frequency transfer function (magnitude) of the channel and want to design a pre-equalizer for that. I have been reading "Understanding Digital Signal Processing - Lyons", "Digital Signal Processing...


BER of multipath channel

Started by Richard_K in comp.dsp14 years ago 4 replies

I wrote a program to calculate the BER of LMS equalizer in AWGN and multipath channel. The tap weights of the mobile radio channels...

I wrote a program to calculate the BER of LMS equalizer in AWGN and multipath channel. The tap weights of the mobile radio channels are normalized to 1 (the exact value is 1.0062). Surprisingly, I found out that the performance of the equalizer in multipath channel is better than the one in AWGN. Is this acceptable? Or anything that might be wrong in my simulation? Or the performance gain of ...


does the equalizer come before the matched filter or after?

Started by bharat pathak in comp.dsp10 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?


Ungerboeck metric for MLSE Equalizer

Started by Pave...@gmail.com in comp.dsp13 years ago 3 replies

Hello. Who can give me some description about Ungerboeck MLSE equalizer? I use it for GSM burst equalization and get strange result - it...

Hello. Who can give me some description about Ungerboeck MLSE equalizer? I use it for GSM burst equalization and get strange result - it works bad. BER is increased as comparision with no equalization. I estimate Channel Impulse Response and use it for signal reconstruction in eaualizer but it works bad. So I make symbol-by-symbol decisions. Can you guide me to additional information about M...


branch metric of MLSE equalizer for GSM

Started by richard_zhang in comp.dsp12 years ago 2 replies

Hi All, I am reading an article about GSM MLSE equalizer. The article link...

Hi All, I am reading an article about GSM MLSE equalizer. The article link is here. http://www.freescale.com/files/dsp/doc/app_note/AN2943.pdf?fpsp=1&WT_TYPE=Application%20Notes&WT _VENDOR=FREESCALE&WT_FILE_FORMAT=pdf&WT_ASSET=Documentation This article is quite brief, and I have two questions here 1) is the Equation 6 in the article correct? 2) How can I get Equation 6 from Equation 5


MMSE and ZF equalization in OFDM systems

Started by Dan25 in comp.dsp6 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. _...


Channel equalization for MSK

Started by Vikram Chandrasekhar in comp.dsp17 years ago 4 replies

Hello, I am trying to set up an adaptive LMS adaptive equalizer to apply the equalizer on a phase modulated signal eg: MSK. For modulation...

Hello, I am trying to set up an adaptive LMS adaptive equalizer to apply the equalizer on a phase modulated signal eg: MSK. For modulation schemes such as PSK/QAM, the effect of a channel filter leads to severe ISI and hence channel equalizers are very important. Further, they have been extensively documented and well-studied. How severe is the effect of a channel filter on a MSK type si...


Definition for transversal equalizers

Started by huke in comp.dsp16 years ago 21 replies

Hello Everyone, Can anyone point me the definition for a transversal equalizer? Some books only treat linear and adaptive equalizers, and some...

Hello Everyone, Can anyone point me the definition for a transversal equalizer? Some books only treat linear and adaptive equalizers, and some talk about transversal equalizers. It seems that all linear equalizer are transversal equalizers but I not convinced that this is true and I do not know if the opposite holds as well!? Very confused!! Pointers to references are also appreciated. ...


Implementing a graphic equalizer on speech

Started by J. Mike in comp.dsp16 years ago 4 replies

I'm a bad with signal processing but an experience c++ programmer. I have implemented a code on a real-time man's speech that makes a pitch...

I'm a bad with signal processing but an experience c++ programmer. I have implemented a code on a real-time man's speech that makes a pitch change. The algorithm works fine in the time domain and implements overlapping windows(50% overlapping). Now I want to add a graphic equalizer and use the same blocks for that. I was told that implementing an fft procedure on the blocks with a variable f...


Timing adjustment and equalizer in a modem

Started by Fender123 in comp.dsp11 years ago 3 replies

Hi all, I have a question on timing adjustment and equalizers, and in my case the application is for a simple low speed PSK modem. I am using...

Hi all, I have a question on timing adjustment and equalizers, and in my case the application is for a simple low speed PSK modem. I am using a half-symbol spaced passband complex equalizer, so basically we are pumping samples at B/2 (B is the baud rate). There is no preceeding interpolator, and the sample rate is not locked to the symbol rate. Now, I am also using a Gardner-type timing e...


channel equalizer using rls algorithm

Started by Thiruppa in comp.dsp12 years ago 3 replies

hi i need help to do rls algorithm in matlab-- i have to do channel equalizer for given channel response --using rls algorithm ...

hi i need help to do rls algorithm in matlab-- i have to do channel equalizer for given channel response --using rls algorithm h(z)=1/1+0.8(1/z) no of tabs 2,4 (various updation co -effi) calculate minimum error and convergence time -plz help --i need to know no of tabs and convergence time plz give solution for this -which material w...


LMS Equalizer fo SC_FDE

Started by adi_sharma1984 in comp.dsp12 years ago 2 replies

Hi All, I am trying to simulate a SC-Frequency domain LMS equalizer. Now since it is SC the detection has to be in time domain although...

Hi All, I am trying to simulate a SC-Frequency domain LMS equalizer. Now since it is SC the detection has to be in time domain although the channel estimation is in frequency domain so i follow these steps 1) Multiply data -> data_f (in frequency domain) with weights in frequency domain 2} Convert data in time domain data_t by ifft and pass it through detector. 3) compute the error (det


Delay estimation

Started by Vladimir Vassilevsky in comp.dsp10 years ago 6 replies

Hello All, There is a communication channel with nonminimum phase response. The channel could be described as H(s)=P(s)/Q(s). The channel is...

Hello All, There is a communication channel with nonminimum phase response. The channel could be described as H(s)=P(s)/Q(s). The channel is equalized by a linear equalizer. The equalization is near perfect but there is a delay lag in the (equalizer + channel) due to the nonminimum phase part of the response. What would be an efficient way to estimate this delay lag, knowing the equal...


low frequency response of adaptive equalizer?

Started by mk in comp.dsp14 years ago 12 replies

Hi, I have an LMS based adaptive equalizer which mostly works well but it doesn't tolerate low frequency inputs too well. The channel...

Hi, I have an LMS based adaptive equalizer which mostly works well but it doesn't tolerate low frequency inputs too well. The channel consists of two transformers (high pass) and cable (low pass) and when there is long periods of no-change in data (which is possible unfortunately even though the data is scrambled) and the SNR goes down during these long periods of no change. I think this is ...


T/2 -spaced FSE MMSE equalizer, with carrier offset

Started by jia in comp.dsp14 years ago 10 replies

Hi, here I am now doing a project about T/2 -spaced FSE MMSE equalizer based on the stochastic gradient algorithm. I use training symbol...

Hi, here I am now doing a project about T/2 -spaced FSE MMSE equalizer based on the stochastic gradient algorithm. I use training symbol method to update the coefficient. It seems working well in some channel distortion enviroment. However, when carrier offset exists, i.e. (the constellation of QAM rotates), this algorithm doesn't converge, even I force the update coefficient steps very...


Minimization of phase error fluctuation in OFDM equalizer

Started by danael in comp.dsp11 years ago 2 replies

I am designing ofdm equalizer.Ofdm frame contains: -19 symbols -24 subcarriers per channel -pilot symbols that are comb type arranged -BPSK...

I am designing ofdm equalizer.Ofdm frame contains: -19 symbols -24 subcarriers per channel -pilot symbols that are comb type arranged -BPSK modulation The period of one frame (19symbols) is 625us,pilots are inserted every four symbol in time direction and every four subcarrier in frequency direction. I made real measurements to determine the channel nature between base station and rece...


Question about Reed-Solomon error control code

Started by Anonymous in comp.dsp16 years ago 2 replies

Hi, I am simulating equalizer with Reed-Solomon channel code a frequency fading channel. The fading channel has a severe spectral null, I...

Hi, I am simulating equalizer with Reed-Solomon channel code a frequency fading channel. The fading channel has a severe spectral null, I use frequecy domain equalization to contre the null. At present I think the equalizer works well. When I add the RS(170,180) (8 bit) channel code for a data frame, I find the BER performance is not improved at all. It is even worse a little bit than that o...


Real-time Tunable Digital Music Equalizer and Amplifier

Started by K_Guna in comp.dsp11 years ago 3 replies

Can anyone tell how to create Real-time Tunable Digital Music Equalizer and Amplifier implementing it using the IIR. Thx in advance. Guna.K.

Can anyone tell how to create Real-time Tunable Digital Music Equalizer and Amplifier implementing it using the IIR. Thx in advance. Guna.K.