MIMO-OFDM systems

Hi all,

I've been looking at MIMO-OFDM based systems for about the last week
(802.11n and 802.16) and have a couple of questions that I was hoping
someone out there could answer. Here goes:

1) I want to look (in detail) at one of the more computationally
demanding blocks of a typical MIMO-OFDM reciever. The main blocks that
I have really been looking at have been a QR-based channel estimator, a
Sphere decoder and Turbo decoder. What I would like to know is, if you
were given the task of implementing a MIMO-OFDM system, what "block" or
section of the algorithm would you consider to be a most
computationally complex, i.e. what block is the limiting factor in
terms of implementation complexity?

2) Are there any models freely available on the internet that model a
MIMO-OFDM system, MATLAB, C++ etc...?

4) If a model is not available on the internet, I will implement my
own. What components of such a simulation are important in producing a
representative MIMO-OFDM based system? Do you know of any other
(simpler) models that work along the same lines (802.11a for example)
that are freely available upon which I may base my work?

3) Up until now I've been looking a papers on MIMO-OFDM based systems,
do you know of any books on this subject?

Thanks very much for the help,

Stephen

Dear,

MIMO OFDM are two separate topics (MIMO + OFDM).
I guess you should tackle each topic separately in the begining.
YOu can start by studying and reading about OFDM,Implement you own OFDM
system,  then you implement a MIMO channel system.

YOu can check this link for OFDM books:
http://www.amazon.com/exec/obidos/search-handle-url/ref=br_ss_hs/002-4286791-4825616?platform=gurupa&url=index%3Dstripbooks%3Arelevance-above%26dispatch%3Dsearch%26results-process%3Dbin&field-keywords=OFDM


Thanks
Hany




Steve wrote:
> Hi all,
>
> I've been looking at MIMO-OFDM based systems for about the last week
> (802.11n and 802.16) and have a couple of questions that I was hoping
> someone out there could answer. Here goes:
>
> 1) I want to look (in detail) at one of the more computationally
> demanding blocks of a typical MIMO-OFDM reciever. The main blocks that
> I have really been looking at have been a QR-based channel estimator, a
> Sphere decoder and Turbo decoder. What I would like to know is, if you
> were given the task of implementing a MIMO-OFDM system, what "block" or
> section of the algorithm would you consider to be a most
> computationally complex, i.e. what block is the limiting factor in
> terms of implementation complexity?
>
> 2) Are there any models freely available on the internet that model a
> MIMO-OFDM system, MATLAB, C++ etc...?
>
> 4) If a model is not available on the internet, I will implement my
> own. What components of such a simulation are important in producing a
> representative MIMO-OFDM based system? Do you know of any other
> (simpler) models that work along the same lines (802.11a for example)
> that are freely available upon which I may base my work?
>
> 3) Up until now I've been looking a papers on MIMO-OFDM based systems,
> do you know of any books on this subject?
> 
> Thanks very much for the help,
> 
> Stephen

Thanks for the help,

I'm aware that MIMO and OFDM are two different concepts: one is a
multicarrier modulation scheme and the other is a method of improving
diversity on a wireless channel. What I would like to know is how these
two scheme fit together in a system and what the most significant block
in such a system would be.

Stephen

It's very hard to say that there is a significant or dominant block for
the system..
It's quite complecated complete system in whcih you can notice that all
the blocks are hardly needed.

Maybe the most significant block for OFDM system is the IFFT/FFT block
(IF I could say).


Thanks
Hany