A Game Theory Based Relay Selection For Cooperative Communication

Cooperative communication is a spatial diversity technology which is suitable for single antenna users. It can improve the performance of mobile communication system without increasing the complexity of infrastructure. Because cooperative communication can improve system transmission rate, extend the transmission range, enhance the system reliability and reduce system power consumption, it becomes one of key optimization techniques for next-generation wireless network.In cooperative communication, the source node can select one or more relay nodes to transmit data together. How to select the relay node is an important research point in cooperative communication. Most of the existing relay selection schemes fix the number of relays, and they are not suitable for dynamic wireless network environment. Based on the coalitional game, this paper studies the optimal relay selection problem and emphasis in three parts below:1. This paper models the optimal relay selection problem as a coalitional game problem. In game theory, coalitional game emphasizes the group rationalism and the members of the coalition act together in order to achieve a common purpose. In cooperative network, the source nodes and relay nodes have the common interest of performance enhancement in cooperation operation. At the result, coalitional game can be used in relay selection process to improve the overall system’s transmission utility.2. In the network with one source node and multiple relay nodes, this paper models the optimal relay selection problem as a coalition game problem, and proposes a coalition formation algorithm based on ant colony algorithm. Simulation results show that the proposed algorithm enables the source node and relay nodes to form the best coalition dynamically and improves the system’s throughput.3. In the network with multiple source nodes and multiple relay nodes, this paper studies an optimal relay selection problem which aims to select the optimal number of relay nodes for each source and destination to obtain the maximal transmission throughput. A coalitional game based relay selection algorithm is proposed to solve the problem. In order to reduce the complexity of coalition formation, a merge-and-split rule is used in the algorithm. We carry out extensive simulations to evaluate the performance of the proposed algorithm. The simulation results demonstrate the significant performance enhancement by using the proposed algorithm.