Coalitional Games in Receiver Cooperation for Spectrum Sharing

The issue of sharing spectrum through receiver cooperation in wireless networks is studied under the framework of coalitional game theory. In particular, we consider two illustrative network models: (1) a Gaussian interference channel with receiver cooperation and (2) a multiple access channel (MAC) with linear multiuser detection. Allowing any arbitrary sharing of the sum-rate achieved by a coalition between member links in a Gaussian interference channel, it is shown that the grand coalition (coalition of all receivers) maximizes spectrum utilization and is also stable. For the linear MMSE multiuser detector, it is shown that the grand coalition is always stable and sum-rate maximizing, while for the decorrelating multiuser detector, the above observation is shown to be true only in the high SNR regime. Finally, transmitter cooperation in the context of a Gaussian interference channel is discussed, with focus on some open problems and a simplified framework for the resulting coalitional game is proposed.