Binary Information Press
In the Pilot Symbol Assisted OFDM (PSA-OFDM) system, the performance of channel estimation is largely dependent on the pilot signals, which typically include the pilot density and pilot location. For a real channel, the authors first estimate the maximum time delay and the maximum Doppler frequency shift, respectively. Based on these two parameters, the optimal pilot number can be determined numerically for a fading environment. Different pilot number is appropriate for different channels. Analytical and simulation results show that the authors' methods are of lower system overhead and higher efficient data transmission than the existing fixed pilot pattern of 802.16a protocol.