Dear all,
I have a problem in understanding LMMSE channel estimation in comb-pilot type of
OFDM. I get stuck to find the auto covariance matrix of the pilot channel. for
example:
I have a channel impulse response (CIR) of length 30 and my OFDM symbol has 128
subcarriers. I place the pilot at 1:16:128. In order for me to find the channel
in freq. domain is by FFT the CIR with zero padding it to 128 . matlab command:
Hf= fft(CIR,128) --> can we do this?.the auto covariance matrix is given by in
matlab as Rhh=Hf*Hf'.But in order to find the auto covariance matrix for
the pilot channel, I used Hp=Hf(1:16:128) and then Rhphp=Hp*Hp'
Is this correct? please advise because I'm not sure how to find the pilot
channel. If anyone who has an example on how to apply the comb-pilot channel
estimation in MATLAB, I really appreciate it if you can share it with me.
best regards,husna
