Non-Coherent LDPC Decoding on Graphs

Abstract

Within this paper graph based non-coherent decoding algorithms for LDPC encoded systems are proposed. We study a class of LDPC codes suitable for non-coherent detection. On the basis of the related graphs a non-coherent decoding algorithm with variable trade-off between computational complexity and BER performance is derived. The proposed scheme is also capable to deal with pilot symbols if available. Finally, the excellent performance of the proposed methods is verified by simulations.

A Low-Complexity LDPC Coding Scheme for Channels With Phase Slips

“…In analogy to the class of symmetric codes [12], which is defined such that the inversion of a complete codeword is another codeword, we call the proposed generalized class of codes blocksymmetric (BS) codes.…”

“…The solution in [5] was to use a multi-level coding approach and to use separate symmetric LDPC codes [12] for bits b 1 and b 2 . With an outer differential decoder, a phase ambiguity of a whole codeword can be resolved.…”

Graph-Based Soft Channel and Data Estimation for MIMO Systems with Asymmetric LDPC Codes

“…To eliminate the potential permutation ambiguity, the interleaver patterns must be antenna-specific. Using asymmetric LDPC to avoid phase ambiguity is a relatively new idea [2], whereas using different interleaver patterns to separate superimposed data streams is a well-proven method from the field of interleave-division multiple access (IDMA) [3].…”

“…In this paper, we will try to exploit the potential of channel coding to eliminate systems dependence on training. We apply asymmetric LDPC codes [2] to remove phase ambiguity, and use antenna-specific interleaver patterns to accomplish layer separation. The use of training is no longer mandatory, and all strict requirements on training design are eliminated.…”