Hi,

This has been a very informative forum while i have been working on thi
small simulation. I have a couple of questions now.

1) First I am simulating a simple uncoded 16-QAM OFDM system. I trie
evaluate the performance of such a system in an AWGN channel and th
results i have matches results of a single carrier system using 16 QAM i
a AWGN channel.

2) Now I would like to study the effects of cyclic prefix in an OFD
system and do that i have made the necessary modifications to m
transmitter and receiver. Specifically, i add the cyclic prefix at th
transmitter pass it through a multipath channel, remove the cyclic prefi
at the receiver before the FFT operation at the receiver.

3) The multipath channel i consider have static paths ( No fading, N
Dopper ).

My question is : For such an uncoded system what channel impulse respons
can i consider whereby i can see the benefits of the cyclic prefix.
A comparison of channel impulse response vs prefix lengths ( greater an
less than impulse response length) is what i have in mind.

Also, I am not clear on what sort of compensation needs to be done at th
receiver for the channel. If we assume perfect knowledge of the channel a
the receiver an operation of the form FFT(Y)./FFT(h) would suffice ?, wher
Y is the received signal before FFT operation and h is the impuls
response


Thanks