Abstract:
The use of channel adaptive transmission techniques requires accurate channel state
information (CSI) which may not easily be achievable particularly near the cell
boundary in multi-cell environments. In this paper, we consider the improvement of CSI
estimation accuracy by exploiting the preamble signal as well as the pilot signal in
ODFM based wireless systems. We first estimate the CSI from both the received
preamble signal and the received pilot signal. By exploiting the channel correlation
between the preamble and pilot signaling, we combine the two CSIs estimated from the
preamble and pilot signals. The combining weight is analytically determined to
minimize the mean squared error. For the interference cancellation with the use multiple
receive antennas, we also consider the estimation of interference channel in a similar
manner. Simulation results show that when applied to the mobile-WiMAX system, the
proposed scheme is quite effective near the cell boundary.