Multi-User Transmissions for Relay Networks with Linear Complexity
Liangbin Li, Yindi Jing, Hamid Jafarkhani · arXiv (Cornell University) · 2010
This paper considers transmission and detection schemes in a (J, R, N) multi-access relay network (MARN), where J single-antenna source nodes send independent messages to one N-antenna destination node through one R-antenna relay node. For complexity considerations, the network is under two linear constraints. The relay node linearly maps its received signals to generate the forwarded signals without decoding and the destination node has linear decoding complexity in the number of users. We propose two protocols to allow multi-user concurrent transmission in the network. Using distributed space-time coding (DSTC) at the relay and zero-forcing interference cancellation (IC) at the receiver, the protocol of DSTC-ICRec allows concurrent transmission in both the source-relay link and the relay-receiver link. When J = 2J-1, TDMA-ICRec achieves the maximum interference-free (int-free) diversity of R, at a lower symbol rate compared to DSTC-ICRec.