Fast distributed resource allocation for multi-cell cognitive radio systems

Cognitive radio offers an attractive means of utilizing spectral resources opportunistically, yet relies on an agreement that the secondary users do not interfere with the primary users. This system-wide constraint makes distributed resource allocation difficult. In this paper, sum rates for a multiuser cognitive radio system under received power constraints are derived and optimal and suboptimal power assignments are found for orthogonal resource sharing and simultaneous transmission scenarios. By allocating a portion of the primary user constraints to each basestation, a novel rate-maximizing distributed technique by which each multi-antenna basestation controls the parameters of its own secondary users is proposed and evaluated. Though suboptimal, the computational burden of the proposed algorithm is minimal compared to the NP-hard optimal solution.