A cooperative routing protocol based on geographic information for two-way amplify-and-forward relay networks

In this paper, we first propose a new cooperative multihop transmission structure for two-way amplify-and-forward (AF) relay networks, in which multiple single-antenna relays are considered and distributed between two sources. With the proposed transmission structure, a multihop network can be decomposed into several independent two-way two-hop AF relay systems. Based on the structure characteristics, we then present a cooperative two-way routing protocol based on geographic information, which mainly consists of a forwarder selection part and a relay selection part; the former aims to minimize the number of transmission hops, and the latter is used to improve the reliability of communication links. We obtain the coverage regions of available relays and forwarders based on an asymptotic symbol error probability (SEP) analysis, and then combine the results with geographic information for minimum-SEP relay selection and maximum-coverage forwarder selection. It is shown that the proposed approach provides better effective throughput performance than a related method. Simulation results are given to validate the analyses as well as to demonstrate the effectiveness of the proposed approach.