Reduced-complexity sequence detection

摘要

Reduction of the complexity of a Viterbi-type sequence detector is disclosed. It was based on elimination of less probably taken branches in the trellis. The method is applied to the design of the E<2>PR4 channel with 8/9 rate sliding block trellis code. Coding, by itself eliminates two states by coding constraints, and the disclosed method reduces the number of required ACS units from 14 to 11, while reducing their complexity as well. For the implementation of E<2>PR4 detection, 4 4-way, 3 3-way, 3 2-way and one 1-way ACSs are needed. System simulations show no BER performance drop at common SNRs when compared with a full 16-state E<2>PR4 implementation in magnetic disk drives. <IMAGE>