Resource Allocation in Cooperative Communication Using Coalitional Game Theory

Abstract

The propagation of radio waves for communication purpose through the wireless medium is affected by lot of impediments on their way. Among other impediments, fading is one such experience which has been an area of significant interest among the research fraternity in order to evaluate the performance of a digital communication system. Among the various techniques, Diversity is one of the leading techniques to deal with the severity of fading induced in a signal transmitted over a channel. The goal for a system designer is to reach at a unified set of mathematical models characterized by diversity combining techniques. Spatial diversity is a well known method to generate autonomous communication paths between the source and the destination through the use of several antennas at the source and/or destination. Cooperative communication in recent times makes use of the mobile users in a network to relay the original source signal to the destination which creates a virtual form of multiple-input and multiple-output (MIMO) antenna array system. In cooperative communication multiple users in a mobile radio environment share their antennas in order to achieve transmit diversity creating a virtual MIMO scenario. Because of its inherent advantages, cooperative diversity is a burgeoning field in wireless network communication systems. The main purpose behind cooperative communication is to improve outage probability, symbol or bit error rate. Besides this reliability improvement, cooperative diversity communication also improves transmission rate. Sometimes the source node can’t realize reliable communication with the help of only single relay node, so in order to achieve desired quality of service some relay nodes would like to form a group to transmit cooperatively. The transmit power of every selected relay node thus can be reduced. Thus the relays have incentive to form coalitions to relay the data of relay nodes. The SNR allocation of the selected relay node based on the Shapley value, which divides the payoff among relay nodes in a fair and equitable way, can lead to the least power consumed for relay nodes. As a result there is much interest shown by the research fraternity in coalition in cooperative communication. The coalitional games provide proof to be a very powerful tool for designing robust, fair, efficient and practical cooperation strategies in communication networks.