Sub-band beamforming of OFDM signals in time varying multi-path fading channel

Abstract

In this paper, a semi-blind beamforming algorithm is proposed for Orthogonal Frequency Division Multiplexing (OFDM) signals to combat multipath fading which is based on semi-blind beamforming of each sub-band in a OFDM system using Decision Directed Algorithm (DDA). The proposed algorithm is simulated for time varying channel with Clark model for block to block variation of the channel coefficients it is shown that without semi-blind operation error floor occurs in the performance of the sub-band beamformer but in the blind mode of the operation, by exploiting the information contents in the decisions the sub-band beamformer provides efficient bit error rate versus 0 / N Eb even in different block length and