Distributed coalition formation algorithms for cooperative broadcast networks with SWIPT

This paper addresses the application of coalitional game theory to cooperative broadcast networks with simultaneous wireless information and power transfer (SWIPT). To improve the reception reliability of destinations with poor channel conditions, we first divide destinations in the network into two types. The first type, Type I, refers to the destinations with the capability of successful decoding. They will help other users by first performing SWIPT and then relaying the source messages with the harvested energy. The second type of nodes, Type II, have poor connections to the source and hence compete to obtain help from Type I destinations. In order to maximize the data transmission rate of Type II destinations in a distributed manner, we model the cooperative scenario as a coalitional game and propose two coalition formation approaches with different payoff functions. One payoff function is based on how much help a destination can contribute or receive. The other payoff function considers the targeted data rate and ensures much better fairness among destinations. Finally, we propose a distributed coalition formation algorithm where destinations decide individually which coalition to join. Simulation results show that the proposed two cooperative schemes outperform the non-cooperative scheme, and the cooperative scheme II performs better than the cooperative scheme I as expected.