On Structured-Summary Propagation, LFSR Synchronization, and Low-Complexity Trellis Decoding

A general idea—message passing with messages that have some nontrivial Markov structure—is outlined. This general idea is worked out for one particular application, viz., the synchronization (state estimation) of “noisy” linear-feedback shift register sequences. For this application, the flexible tradeo between performance and complexity is demonstrated by simulation results. Generalizations to lowcomplexity approximations of the BCJR algorithm are outlined.

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