Ultra-Reliable Wireless Communications via Incremental Redundancy and Space-Time Coding

Abstract

Multi-hop relaying has emerged as a key technique for ultra-reliable communications due to its ability to harness spatial location diversity while avoiding interference. In this framework, the user messages are aggregated into a single packet and broadcast to all the receivers in multiple phases, thus allowing the stronger receivers to relay the packet to the weaker receivers. Prior implementations of the above framework, however, typically do not leverage the past received signals to improve message decoding. This paper proposes using incremental redundancy coding with coordinated decoding across the multiple phases, in conjunction with transmission using space-time coding, to enable higher achievable rate overall. The resulting scheme provides significant improvement over the existing methods. Moreover, we propose an extension that incorporates multi-cell interference management.