Turbo equalization utilizing soft decision feedback

In this paper, we discuss an efficient soft decision feedback (SDF) scheme that alleviates error propagation. Error burst statistics observed at the output of the outer decoder indicate that error propagation is successfully suppressed. Sector error rate analysis is also performed under the assumption that a Reed Solomon (RS) code is used to clean up the errors that remain after concatenation of a channel detector and a recursive systematic convolutional (RSC) code decoder. Results indicate that compared to a reference system where the optimal BCJR algorithm is used both to detect the generalized E2PR4 (GE2PR4) target and to decode the outer RSC code, performance is comparable if, we replace the BCJR-based ISl detector in the reference system with a CD detector with SDF. The relative complexity savings of the proposed scheme is very large compared to the reference system.