Sequence-based BDFE with soft feedback for turbo equalization

A sequence-based block decision feedback equalizer (BDFE) with soft feedback is presented for turbo equalization. The proposed algorithm can be used in the channel equalization for calculation of the a posteriori probability (APP) by collecting information of the entire block as in maximum a-posteriori probability (MAP) algorithm. The sequence-based detection is made possible by combining both soft a priori information from channel decoder and soft feedback from BDFE. Replaced hard feedback with soft feedback reduces the effects of the error propagation. Meanwhile, combining soft feedback with sequenceed-based detection can provide more reliable information for the calculation of the APP. Simulation results confirm the superiority of the new proposed equalizer comparing with current low complexity turbo equalizers with similar complexity.

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