Downlink Channel Estimation Based on Regularized Low-Pass Filter for Multi-antenna Mobile WiMAX Systems

Mobile worldwide interoperability for microwaves access (WiMAX)based on the IEEE 802.16e-2005 specification is one of the promising candidates for the fourth generation communications. Channel estimation, which plays a very important role in mobile WiMAX communications, is a tackle problem especially for multi-antenna systems due to limited number and irregular spacing of pilots. This paper proposes a channel estimation method based on the regularized low-pass filter with the aid of the time shift orthogonal pilot sequences in the code domain for downlink multi-antenna mobile WiMAX systems. Simulations demonstrate that the proposed channel estimation method cannot only outperform the existing methods significantly in terms of performance of frame error rate, but also support more transmit antennas.