Abstract-The problem of sharing multiple channels owned by primary users with multiple cognitive users is considered. Each primary user transmits on its dedicated channel, and its occupancy is modeled by a continuous time Markov process. Each cognitive user is capable of sensing one channel at a time and it transmits according to a slotted structure. The transmissions of cognitive users on each channel are subject to a prescribed collision constraint. Under tight collision constraints, the maximum throughput region is obtained by a policy referred to as Orthogonalized Periodic Sensing with Memoryless Access (OPS-MA). Characterizations of the maximum throughput region are also provided when the collision constraints are loose. It is shown that the OPS-MA policy achieves the maximum sum-rate under all collision constraints when the number of cognitive users equals to that of the primary users. Inner and outer bounds for the effective bandwidth region are formulated as a pair of convex optimizations. When there are only two channels, corner points (the single user scenario) of the optimal effective bandwidth region are also obtained. Index terms-Cognitive radio networks, dynamic spectrum access, opportunistic multiaccess, effective bandwidth, Constrained POMDP, queueing networks.
The optimality of OPS-MA is shown in REF for Markovian channel occupancy.
Multiuser cognitive access of continuous time Markov channels: Maximum throughput and effective bandwidth regions
2010 Information Theory and Applications Workshop (ITA)
2010 Information Theory and Applications Workshop (ITA)
Computer Science