Performance analysis of a buffer-aided incremental relaying in cooperative wireless network

This paper presents an incremental cooperative communication scheme for a buffer-aided three node relay network consisting of a source, an Amplify and Forward (AF) relay and a destination. We consider the presence of direct link and propose a scheme which is based on the concept of packet diversity rather than link diversity. The scheme is designed in such a way that packets that experienced bad channel conditions in source-relay link experience good channel conditions in the relay-destination link and vice versa. Source multi-casts all packets to both relay and destination. If direct transmission is not successful, source needs assistance from the relay. Based on the quality of relay-destination link, a packet is picked from buffer at the relay to be transmitted to the destination. Further, direct and relayed signals are combined at the destination using Maximal Ratio Combining (MRC) technique. The closed-form expressions for outage and error probabilities are derived, further, the delay and the diversity orders for the proposed scheme are also investigated.