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Hello
I am a new engineer in the DSP field.
I have to implement an equalizer for our mp3 decoder.
The equalizer must include 4 modes, which is pop, rock, classic and
jazz.
The equalizer and mp3 decoder are implemented using ADI-2181 DSP.
Would you please tell me where to find the information a...
Richard_K - 2006-12-27 16:59:00
Hi,
If we compare LMMSE (non-adaptive) equalizer and LMS adaptive equalizer in
time-invariant channel, which equalizer should achieve better performance
in terms of MMSE and BER? Why?
Thanks.
...
richard_zhang - 2008-06-09 21:47:00
Hi all,
I am doing GSM software defined radio and trying to use normalized LMS
algorithm to implement an equalizer, since LMS has low complexity. But now
I find that the BER is not improved at all after adding the equalizer
block.
I just simply take the normalized LMS algorithm and use it, and...
CONTEXT:**********************
Transmit x(n) receive y(n). Wiener-Hopf (MMSE) FIR Equalizer is...
w = inv(Ryy)rxy
where Ryy is the received signal autocorrelation and rxy is the
channel input-output crosscorrelation: rxy(k) = E(x(n-D)y(n+k)). The D
is a delay parameter chosen to make sure the...
despite - 2008-05-03 12:13:00
Hello,
Could you please give me an example of adaptive algorithm that can be used
for a zero forcing equalizer.
I am a bit confused. If I would like to use peak distortion as cost
function, could I use LMS algorithm to make my equalizer adaptive??.
-If yes, how?
(Because the error fed to LMS a...
Richard_K - 2006-10-21 11:04:00
Is fractionally spaced equalizer (FSE) applicable to the linear adaptive
transversal filter? I noticed that most of the FSE is applied for the
decision feedback equalizer (non-linear).
May I know what are the advantages of using FSE over symbol spaced
equalizer?
Thanks.
...
Hi all,
I want to find a way to do the "Equalizer" (similar to equipment on audio
amplifier) using software (maybe C or others) on PC, should I use the filter
bank technique? Or can I simply use FFT and just change amplitude of
frequency components, then take inverse FFT? Is there open source ...
aamer - 2007-02-14 03:48:00
Hi,
How do I choose number of taps in an equalizer?? does it depends on number
of multipaths??? Is the signal delayed deliberatey in the equalizer or its
the signal delayed in the channel with some delay spread??? Am quite
confused. Can someone quote me a good E-source on equalizers?????
kin...
Davy - 2006-01-02 22:57:00
Hi all,
I am new to equalizer and adaptive filter. My tutor told me to minimize
a DFE(decision feedback equalizer)'s area while keep its timing.
I got a book named "Pipelined Adaptive Digital Filters" by Parhi. But
the book seems aim at high speed.
Can you recommend some book or paper on ...
ericknightX - 2007-04-01 04:05:00
hi all,
Generally i have coded my OFDM system, but i have some problem in
understanding about the one tap equalizer.
Actually i know how to generate a ZF equalizer , but i would like to know
how to generate MMSE equalizer, even i have the algorithm , but i dont
understand the symbol stand for,...
Richard_K - 2006-12-30 19:42:00
From literature study, I noticed that MMSE equalizer (non-adaptive
type)has been used to equalize the multipath effect in time-varying
channel. May I know how these simulation are conducted since the channel
is time varying while there is no adaptation mechanism for the equalizer?
Please help. ...
zohreh - 2007-08-01 11:17:00
Hi there,
Is there anyone know how I can convert the coefficients of
Fractionally-Spaced-Equalizer to the coefficients of Symbol-Spaced
Equalizer?
I know it can't be done by downsampling the output of this filter fed by
Impulse input!
...
zaman - 2008-08-18 10:46:00
Hi,
I want to do simulation on MLSE equalizer for optical QPSK/DQPSK signal
first then i will go for experiment.
I need Matlab file for that.
I have read some recent papers on that but i dont understand the basic
things of MLSE clearly for optical communication.
Can anyone provide me any resou...
2009-03-09 23:49:00
Hi,
First question:
I wonder if I should place the equalizer before or after the Gardner
Timing Recovery loop.
It is about a BPSK/QPSK digital demod.
If the equalizer goes before the TED, it should works at 2 samples/
symbol and after it can works at 1 sample by symbol.
All this will be don...
tasi - 2004-06-10 02:35:00
Hi, Greeting,
I am interesting with a fully digital audio equalizer.
For I am a fresh in this field, I don't how to start.
Does somebody can tell me how to get/find a useful information?
Thx
...
Stacy - 2007-11-05 02:30:00
I want to implement a graphic equalizer in S/W.
I assume it is a bunch of bandpass filters with boost/cut at their
respective frequencies.
Has anyone else done this or know of any links?
...
2009-02-25 01:12:00
On Feb 25, 5:27=A0am, "jbdore" wrote:
> Do you perform an equalization on the data before plotting the
> constellation?
>
> JB.
@JB
yes of course JB. do you think that filter imperfections should be
handled by equalizer and i should look into equalizer algorithm? on
baseband simulatio...
zqchen - 2007-07-04 01:30:00
A question puzzled me for days, have to look for help here:
> From the derivation of MLSE, a matched filter is obviously needed
before the equalizer.
Starting from continuous signal, the operation of matched filter and
sampling is so
natural. But so far as I read about MAP equalizer, I doubt ...
ericknightX - 2007-04-06 04:41:00
Hi,all
I would like to find the expected value of my OFDM transmitted signal.
As
Y= H*X + N
Y= Received Signal , H = Channel , X= transmitted signal ,N=noise
Since i need to generate a MMSE equalizer, i need to find the Expected
value of X , in order to do the simulation.
The algor...
tmoshe - 2006-12-12 08:14:00
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
sign...
tmoshe - 2006-12-12 12:00:00
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
sign...
Hi everyone,
I'm considering implementing a fractionally spaced equalizer and one
question which has bugged me in the past is whether a non-integer,
smaller than 2 fractional spacing would have any benefits (ie better
equalization). Suppose the signal rate is 100 M bauds and the signal
bandwidt...
kal - 2004-09-21 02:24:00
Hi,
I have a fully digital receiver where timing recovery and equalizer
are adding significant latency and I would like to try and reduce it
as much as possible.
The timing recovery is done with a fractional delay filter (a farrow
type FIR filter) where only one fractional value which gets mul...
Hi,
I have a channel with significant ISI with a 3 level (1,0,-1)
transmission. The transmitted data and the receiver data after
quantization have zero mean. The problem is that the error output of
the equalizer after convergence is not zero mean even (it's slightly
positive) though its varianc...
Andrew2006 - 2006-12-31 10:20:00
From some technical papers, I found out that non-adaptive MMSE block
equalizer has been used to equalize for time-varying channels. Since
adaptive algorithm (LMS, RLS,....) is not applied here, then how the
researchers simulate for the BER performance?
Can anyone please help?
Thanks.
...
Fender123 - 2010-03-06 08:20:00
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,
a...
zohreh - 2007-08-22 16:04:00
Hi there,
I simulate a system with upsampling 4 at the transmitter. Then, I use the
equalizer and change the main tap. when I use different location for main
tap, the amount of timing error the receiver can beer is different and
depends on the location of the main tap.
Now, I realize that the ...
jia - 2006-06-05 22:50:00
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 constellatio...
Tom - 2007-06-11 12:03:00
I have two complex signals (Input and output) of a channel I need to
equalize. I can have 2 linear equalizers one for the real part and one for
the imaginary and train them independently or I can use one complex
equalizer and train it using the complex signal. My questions are which one
is b...
buaawh - 2008-06-04 10:10:00
Hello,
Well known that decision-feedback equalizer is generally superior than
linear equalizer, I was surprised to read the statement in a paper:
"Finally it is to mention that a combination of channel coding (Viterbi
Decoding) and DFE did not lead to a performance gain compared to channel
cod...
ggch - 2007-05-01 10:14:00
> dear all,
>
> I was trying to implement constant modulus algorithm for blind channel
> equalization. I found that the filter taps of the equalizer are modified
> according to W(k+1)=W(k)+ mu * conj(x(k)) * e(k)
>
> where mu= adaptation size
> W the filter taps.
> x(k)= transmitted symbol...
zohreh - 2007-08-01 07:26:00
Hi there,
I've already use the Fractionally_Spaced-Equalizer at the receiver. I'm
trying to send the coefficient of this equalizer to the transmitter to
have a echo free signals at the receiver. I can get the good result when I
use the symbol spaced equalizer but when I use FSE after upsampler and
...
Richard_K - 2006-12-27 16:56:00
Hi,
Is it possible for a LMS equalizer in multipath environment to achieve
better BER performance as compared to matched filter in AWGN channel?
...
Kuba - 2005-06-02 06:03:00
Hi everybody,
I am new in this group and I have a problem.
I have a project that requires a parametric equalizer on TI C6713.
Can anyone help me with this? I have a little experience with programming TI
( I have made my past projects with Motorola 56300). Do You have some links
that can help ...
rider - 2004-01-25 06:05:00
Hi!
For an all digital BPSK receiver, If I place the Equalizer in
baseband, then what could be its exactloaction: Is the following
arrangement acceptable?
|PASS-BAND|--------------BASE-BAND----------------------|
fs ------ fs ------ fs fb ------ fb -------
r(nTs)---> |DEMO...
mguo - 2006-03-06 12:00:00
>
> mguo wrote:
> > 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 sensi...
2006-04-18 03:02:00
hello,erevyone.Recently I have been designing a blind channel equalizer
based on the Constant Modulus Alogrithm.But I have a question that I
can't think over.The question is as follows:
The alogrithm I use is below:
y(k)=3D =A1=C6f(k)x(N-k);
% f(k+1)=3Df(k)-mu*e(k)*x(k)...
mnentwig - 2007-09-10 13:55:00
Hi,
search for "Equalizer", there is plenty of material on the web.
Simply inverting the filter as said is called "zero forcing equalizer" and
usually it does NOT work.
But building a correction filter that straightens out your PASSBAND may
work very well.
I've got example code here, for ...
mobi - 2006-03-31 10:26:00
I was trying to search through literature in order to find advantages
and disadvantages of adaptive pre-coding and pre-equalization over
adaptive post-equalization. I failed. Can anyone point to a good
reference. 2ndly on adaptive pre-equalization there are only three
papers when we search ieee...
2006-12-11 00:58:00
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
...
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