Channel assignment in non-cooperative coexisting co-located independent cognitive radio networks

Cognitive radio networks provide a reasonable solution to the problem of spectrum scarcity by allowing secondary users opportunistic access to licensed spectrum bands which were till now reserved for exclusive usage of primary incumbent users. The problem of coexistence arises when multiple colocated networks are in close vicinity and have to share the same part of the wireless spectrum. In this paper, the problem of channel assignment which ensures coexistence among co-located, non-cooperative, independent cognitive radio networks has been addressed using a game-theoretic model. We assume that each base station, representing a Wireless Regional Area Network (WRAN), senses its environment (which includes interference experienced due to other communicating WRANs in its vicinity) in a distributed manner to take appropriate decision about its operating channel. This problem is modeled as a non-cooperative repeated potential game in which the players are the coexisting WRANs with customer premises equipment only used to gather information regarding the changing conditions of the channel. The existence of Pareto optimal solution is discussed and an algorithm which converges to such a solution is proposed. Our study shows that the proposed approach provides significant performance gain as compared to existing approaches.