A sensing-based cognitive coexistence method for interfering infrastructure and ad hoc systems

The rapid proliferation of wireless systems makes interfer nce management more and more important. This paper presents a novel cognitive coexistence fra mework, which enables an infrastructure system to reduce interference to ad-hoc or peer-to-peer communica tion links in close proximity. Motivated by the superior resources of the infrastructure system, we stu dy how its centralized resource allocation can accommodate the ad-hoc links based on sensing and predictin g their interference patterns. Based on an ON/OFF continuous-time Markov chain model, the o ptimal allocation of power and transmission time is formulated as a convex optimization pr oblem and structured solutions are derived. The optimal scheduling is extended to the case where the infr astructure channel is random and rate constraints need only be met in the long-term average. Final ly, the multi-terminal case is addressed and the problem of optimal sub-channel allocation discussed. N umerical performance analysis illustrates that utilizing the superior flexibility of the infrastructure li nks can effectively mitigate interference. Index Terms Cognitive Radio; Resource Allocation and Interference Man agement; Standards Coexistence; Dynamic Spectrum Access;