Semi-blind channel estimation scheme with Bayesian DFE for PRP-OFDM system

This paper presents a novel block-based Bayesian decision feedback equalization (DFE) receiver for the Pseudo-Random Postfix (PRP) Orthogonal Frequency Division Multiplexing (OFDM) (PRP-OFDM) systems, with semi-blind channel estimation. In conventional PRP-OFDM receiver for semi-blind channel estimation, an order-one statistics of the received signal is developed, for sufficient redundant symbols (PRP). In this paper, we consider the PRP-OFDM system, where the length of PRP (redundant symbols) is less than the channel order, named as the insufficient PRP-OFDM system. To deal with this problem and maintain reasonable complexity of receiver, first the maximum shortening signal-to-noise-ratio (MSSNR) time-domain equalizer (TEQ) is applied to reduce the effect of inter-block-interference (IBI). After that the block-based Bayesian DFE equalizer is developed for alleviating the inter-symbol interference (ISI), hence to achieve better system performance, in terms of bit-error rate (BER). Computer simulation results verify that the proposed scheme could achieve BER improvement over the conventional block-based equalizers, viz., the linear zero-forcing (ZF) equalizer, non-linear ZF equalizer (with oblique projector) and the minimum mean square error DFE.