Network-coding-based multisource RA-coded cooperative MIMO

This paper proposes a network-coding (NC)-based multisource repeat-accumulate (RA)-coded cooperative multiple-input multiple-output (MIMO) scheme, where multiple sources transmit their messages to the destination with the assistance from the single relay. The relay cooperates with multiple sources simultaneously via network-coding. It avoids the issues of imperfect timing / frequency synchronization and large transmission delay which may be introduced by code-division multiple access (CDMA) / frequency-division multiple access (FDMA) and time-division multiple access (TDMA) manners. The equivalent joint Tanner graph, which characterizes RA codes employed by the sources and relay, is introduced. The joint “Min-Sum” iterative decoding is effectively implemented in the destination based on the equivalent joint Tanner graph. Theoretical analysis and numerical simulations show that the proposed scheme with joint iterative decoding can achieve significant cooperation diversity, multi-receive diversity, and channel coding gains, and outperforms the coded noncooperation scheme.