Comparison of two channel estimation methods

The pilot-assisted channel estimation method was studied in time-division multiplexing Rayleigh fading channel. Known time-multiplexed pilot symbols were transmitted periodically and their channel coefficients were estimated using ML estimation method. An improved channel estimation method employing Chebyshev polynomials as interpolation polynomial is introduced for downlink coherent receiver in LASMAX mobile environment in place of linear interpolation. The performance is compared with linear interpolation with regression method. The optimal orders of Chebyshev interpolation polynomial for channel tracking are found through computer simulations for LASMAX system. The simulation results show that the performance is significantly improved with channel tracking by employing Chebyshev interpolation polynomial at the expense of little increase of computation complexity.