Opportunistic Relay Selection Protocol under Multi-User Environment

In this paper, a relay selection issue is studied to improve data rate performance in a multi-user environment. Previous opportunistic relay selection protocols only consider channel condition in relay selection. However, the target performance is affected by other system attributes, such as delay and load in relay node (RN). The proposed relay selection scheme, which is based on analytic hierarchy process (AHP), adopts signal-to-noise ratio (SNR), switching, and the number of connections to RN as a selection criteria. Also, a special form of eigenvector is proposed and proved analytically. From the proposed eigenvector, the computational complexity is obviously reduced. Target system performance is examined under different weighting parameter values to the above attributes. This work shows that average data rate can be maximized corresponding to the number of RN. Simulation results reveal the benefits of the proposed scheme over the conventional opportunistic relay selection scheme and the threshold-based relay switching selection scheme. The performance of our scheme is verified in terms of average data rate and distribution of the data rate.