Multi-Relay Selection Design and Analysis for Multi-Stream Cooperative Communications

TL;DR

This paper proposes a low-overhead multi-relay selection protocol for multi-stream cooperative MIMO systems, enabling multiple data streams to be transmitted simultaneously and improving outage performance at high SNR.

Contribution

It introduces a novel multi-relay selection scheme supporting multi-stream transmission in cooperative MIMO systems, with asymptotic performance analysis and tradeoff discussions.

Findings

Achieves lower outage probability than baseline schemes.

Supports multiple data streams simultaneously.

Provides asymptotic performance results at high SNR.

Abstract

In this paper, we consider the problem of multi-relay selection for multi-stream cooperative MIMO systems with $M$ relay nodes. Traditionally, relay selection approaches are primarily focused on selecting one relay node to improve the transmission reliability given a single-antenna destination node. As such, in the cooperative phase whereby both the source and the selected relay nodes transmit to the destination node, it is only feasible to exploit cooperative spatial diversity (for example by means of distributed space time coding). For wireless systems with a multi-antenna destination node, in the cooperative phase it is possible to opportunistically transmit multiple data streams to the destination node by utilizing multiple relay nodes. Therefore, we propose a low overhead multi-relay selection protocol to support multi-stream cooperative communications. In addition, we derive the asymptotic performance results at high SNR for the proposed scheme and discuss the diversity-multiplexing tradeoff as well as the throughput-reliability tradeoff. From these results, we show that the proposed multi-stream cooperative communication scheme achieves lower outage probability compared to existing baseline schemes.