Performance Comparison of Different Pilot Aided Channel Estimation Techniques for OFDM IEEE 802.11e (Mobile Wimax) Systems
Orthogonal Frequency Division Multiplexing (OFDM) modulation is a promising technique for achieving the high bit rates required for a wireless multimedia service. In this paper, the authors present different channel estimation algorithms for OFDM mobile communication systems based on the use of pilot subcarriers. Specifically they present LS (Least Square), MMSE (Minimum Mean Square Error) and LMS iterative channel estimation techniques to show the performance comparison of channel estimation techniques supported by n IFFT-based time channel estimation. The channel estimation is based on the principle of Pilot-symbol Aided Channel Estimation (PACE), and it has been implemented using block-type pilot subcarrier arrangements. The low complexity of LMS algorithm, has a higher efficiency than conventional methods (without channel estimation, LS& LMMSE) and it can work in lower amount of SNRs.