Abstract:
The objective of this study is to improve channel
estimation accuracy in OFDM systems, which have high
data rate and channel capacity and adequate performance in
frequency selective fading channels. The first contribution
of the paper lies in highlighting the appropriateness of the
time-frequency representations for the analysis of OFDM
communication systems. We show that the delay and
Doppler spreading are the most important characteristics of
a communication channel and we indicate how can be used
the ambiguity function to estimate these characteristics.
Next, we prove that all the on air wireless communication
channels are identifiable. The channel estimation based on
block-type and comb-type pilot arrangement is studied
through different algorithms such as LS, MMSE, LMMSE.
Experimental results highlight the merits of the method
proposed.
