Analysis on the use of EM algorithm for space time coding in fading channels

Abstract

The BER of space time trellis code is analyzed for the EM algorithm receiver. Using the proposed method of partial detected frame in slow, flat fading channel, it is found that the use of partial frame to estimate the mean is able to improve the EM algorithm further. In the study, the use of a minimum 2 symbols results in a BER performance improvement of 2dB as compared to the use of the whole frame of 128 symbols. Using theoretical analysis and numerical computation, it is shown that the EM algorithm receiver designed for Rayleigh fading is effective in reducing the BER performance in Rician fading channel. The EM algorithm receiver is studied in flat, fast fading channel for various pilot symbol configurations, Rayleigh, Rician and Nakagami fading channels, use of high energy pilots and different number of transmit antennas. The computer simulation results are obtained and explained.