In order to improve channel estimation performance, a new time domain least square method is proposed for the multi-antenna worldwide interoperability for microwaves access system at the downlink partial usage of subchannels mode. We show that the pilots in the proposed method double those of the regular time domain least square method by establishing a hypothetical channel estimation model instead of increasing the additional pilots, in which the frequency outputs of virtual pilots in the current symbol are reconstructed at the positions where the actual pilots of the adjacent symbol are located. We also show that the border effect incurred by the uneven limited pilots, which degrades the performance of channel estimation, can be reduced by using SVD as effectively as regularization. Simulations demonstrate that the proposed method using SVD or regularization can perform better than the conventional approaches, and especially over the pedestrian-B channel for four transmits, it only incurs the performance loss of about 2.5dB at a 0.001 of BER compared to the ideal case, whereas the regular methods cease to be effective due to too rare pilots allocated for each transmit and cannot approach this BER value over the considered Ebi¾?N0 range. Copyright © 2013 John Wiley & Sons, Ltd.
['Wang Dm', 'L. Yang']
Channel estimation for multi-antenna mobile worldwide interoperability for microwaves access downlink partial usage of subchannels systems