Prev: DM642 PCI Master reads not starting
Next: Fast integer distance formula
From: McNab on 4 Oct 2006 11:21
>McNab wrote:
>>> There isn't a lot in this which is blind equalisation related, because

>>> many timing detectors are the first step in the data recovery chain
>>> whether the demodulation is blind or trained. Its really a matter of
>>> excess bandwidth.
>>>
>>> If you have lots of excess bandwidth, things like Gardner work. You
only
>>
>>> need to consider thing like band-edge when the excess bandwidth is
>>> somewhat limited, as Gardner falls apart.
>>>
>>> If the carrier is X, and the symbol rate is Y, the band will be X-Y/2
to
>>
>>> X+Y/2, ignoring the excess bandwidth. Consider what happens if you
>>> filter tightly around those two band edge frequencies, and slide the
>>> baud phase around.
>>
>>
>> Unfortunately I am not guarenteed lots of excess bandwidth, so I guess
>> Gardner is not the solution for me. If you have any references to
>> information on BETR, it would be greatly appreciated.
>
>I thought I provided the clue. Don't you expect to do any work on this?
>
>Steve
>

You did provide me with a clue, but apparently I must be mathematicly
impaired :-). It looked really easy just filtering tightly around the band
edges and getting a good spectral line. I have tried this and for some
reason I must be doing something wrong.

I have tried simulating the approach from "Joint Blind Equalization,
Carrier Recovery, and Timing Recovery for High-Order QAM Signal
Constellations" by Jablon - Only the part preceding the spectral line
filter. Still with no luck.

If it's possible, I could use yet another hint...

Thanks,

NcNab



From: PARTICLEREDDY (STRAYDOG) on 9 Oct 2006 00:10
very good discussions indeed,
really have to appreciate
each and every member of this group for their thoughfull deep insight
answers

i got few papers on this, may be this might be usefull

1. Joint blind equalization, carrier recovery and timing recovery
for high-order QAM signal constellations
Jablon, N.K.;
Signal Processing, IEEE Transactions on [see also Acoustics, Speech,
and Signal Processing, IEEE Transactions on]
Volume 40, Issue 6, June 1992 Page(s):1383 - 1398
Digital Object Identifier 10.1109/78.139243
Summary: Two existing blind equalization tap update recursions for
64-point and greater QAM (quadrature amplitude modulation) signal
constellations are studied, along with existing and novel carrier and
timing recovery techniques. It is determined that the su.....
AbstractPlus | Full Text: PDF(1160 KB) IEEE JNL
Rights and Permissions
2. Joint blind equalization, carrier recovery, and timing recovery
for 64-QAM and 128-QAM signal constellations
Jablon, N.K.;
Communications, 1989. ICC 89, BOSTONICC/89. Conference record. World
Prosperity Through Communications, IEEE International Conference on
11-14 June 1989 Page(s):1043 - 1049 vol.2
Digital Object Identifier 10.1109/ICC.1989.49843
Summary: Two existing blind equalization tap update recursions suitable
for 64-point and greater QAM signal constellations are studied, along
with existing carrier and timing recovery techniques. The superior tap
update recursion is determined to be the const.....
AbstractPlus | Full Text: PDF(384 KB) IEEE CNF
Rights and Permissions

From: McNab on 9 Oct 2006 16:39
>very good discussions indeed,
> really have to appreciate
>each and every member of this group for their thoughfull deep insight
>answers
>
>i got few papers on this, may be this might be usefull
>
>1. Joint blind equalization, carrier recovery and timing recovery
>for high-order QAM signal constellations
>Jablon, N.K.;
>Signal Processing, IEEE Transactions on [see also Acoustics, Speech,
>and Signal Processing, IEEE Transactions on]
>Volume 40, Issue 6, June 1992 Page(s):1383 - 1398
>Digital Object Identifier 10.1109/78.139243
>Summary: Two existing blind equalization tap update recursions for
>64-point and greater QAM (quadrature amplitude modulation) signal
>constellations are studied, along with existing and novel carrier and
>timing recovery techniques. It is determined that the su.....
> AbstractPlus | Full Text: PDF(1160 KB) IEEE JNL
>Rights and Permissions
> 2. Joint blind equalization, carrier recovery, and timing recovery
>for 64-QAM and 128-QAM signal constellations
>Jablon, N.K.;
>Communications, 1989. ICC 89, BOSTONICC/89. Conference record. World
>Prosperity Through Communications, IEEE International Conference on
>11-14 June 1989 Page(s):1043 - 1049 vol.2
>Digital Object Identifier 10.1109/ICC.1989.49843
>Summary: Two existing blind equalization tap update recursions suitable
>for 64-point and greater QAM signal constellations are studied, along
>with existing carrier and timing recovery techniques. The superior tap
>update recursion is determined to be the const.....
> AbstractPlus | Full Text: PDF(384 KB) IEEE CNF
>Rights and Permissions
>
>

I have read reference 1. Unfortunately it pretty much reffered to another
paper by Jablon, Farrow and Chou ("Timing Recovery for blind
Equalization"). It looks like I have to find that as well - It seems like
I'm getting closer to a solution :-)

Thanks for all the help...

McNab


First  |  Prev  | 
Pages: 1 2
Prev: DM642 PCI Master reads not starting
Next: Fast integer distance formula