Coded Bi-directional Relaying

In this paper, bi-directional traffic between two nodes communicating via a relay node is considered. A novel relaying method based on joint data packet encoding in conjunction with exploitation of a priori known information is presented. Moreover, a specially crafted method for combining of the direct and relayed radio signal is suggested. The proposed scheme enables a reduced number of transmissions, whereby enhancing aggregate throughput. Evaluation, where optimal power and rate settings are derived, shows that the proposed method enhances the throughput up to 33% as compared to a (traditional) four-phase bi-directional protocol under a system energy constraint, both with and without the proposed combining method

I. Introduction

Relaying is a hot research area [1] and often envisioned to enable range-rate enhancements of future cellular systems. A basic research challenge is to design more efficient relay schemes than state-of-the-art methods. Here, the focus is on a two-hop bi-directional communication case.