Research On Cooperative Routing In Wireless Network Based On Game Theory

Cooperative communication is a new wireless communication technology. It isan extension of multi-antenna technology and becomes a hot research topic in thefield of wireless communication recent years. Routing mechanism based oncooperative communication is called cooperative routing. Designing cooperativerouting algorithm is able to combine technologies of network layer and physicallayer to save network resources more effectively. Existing cooperative routingalgorithms are mostly designed on the assumption that network nodes totallycooperate to transfer data for others. However, the nodes in wireless network areusually devices with limited resources and they will not unconditionally serve othernodes. Thus fully cooperation is difficult to achieve in actual wireless network. Inorder to solve this problem, we introduce the idea of game. Game theory is capableof designing incentive mechanisms, which makes selfish nodes cooperate with eachother to complete cooperative routing.In order to improve delivery ratio of and reduce energy consumption of selfishnetwork, this paper proposes a VMIMO Group forming algorithm based oncooperative nodes selection game and a VMIMO cooperative routing algorithmbased on repeated routing game in single-interface wireless network. According torational preference of selfish nodes, the algorithms divide network into multiplerational Groups. Some nodes will be chosen to be cooperative nodes whichconstitute cooperative unit in Group. It uses VMIMO transmission mode betweenGroups transmit data through cooperative units of them. This paper models theselection of cooperative units as “cooperative nodes selection game” and modelsVMIMO routing between Groups as “repeated routing game”.The VMIMO Group forming algorithm based on cooperative nodes selectiongame can be divided into two stages. In the first stage, selfish nodes distributedchoose cooperative nodes and constitute cooperative units according to benefitfunction and common benefit constraints. In the second stage, the network is dividedinto groups around different cooperative units. This Group forming algorithm is thenecessary condition of the VMIMO routing algorithm.The VMIMO cooperative routing algorithm based on repeated routing gameincludes routing selection algorithm and routing forwarding algorithm. In order to improve delivery ratio in game routing among Groups, this paper designs fitnessfunction to estimate whether nodes are suit to participate in routing and proposesrouting selection algorithm and routing forwarding algorithm based on fitnessfunction. It used VMIMO transmission protocol to transmit data between Groupsafter routing path has been found.This paper proves the repeated routing game can approach to Pareto Optimality.Simulation results show that these algorithms are capable of promoting cooperationbetween selfish nodes, achieving higher delivery ratio, reducing transmission energyconsumption and saving network resources.