Distributed punctured LDPC coding scheme using novel shuffled decoding for MIMO relay channels

We propose a distributed punctured LDPC coding scheme to approach the theoretical limit for half-duplex MIMO relay channels. Distributed punctured LDPC coding scheme only requires the design of mother code which avoids complicated joint signal design in previous LDPC schemes [6],[7]. For punctured LDPC decoding, shuffled decoding algorithm proposed in [4] can provide good performance, however traditional BP decoding algorithm should also be used for calculating recoverability. Therefore we propose a low complexity algorithm to calculate the recoverability of punctured variable nodes which can reduce nearly 90% computational time compared with [4]. Furthermore, soft information relaying protocol is adopted to allow relay forwarding soft messages to destination. By this method, LLR values received at the destination will become more reliable. The simulation results verify that our proposed methods can achieve better performance comparing with previous reported methods in literature.