Adaptive Hopping Transmission Strategy for Opportunistic Spectrum Access

This paper presents an adaptive hopping transmission strategy for secondary users (SUs) to access temporarily idle frequency-slots of a licensed frequency band in consideration of the random return of primary users (PUs), aiming to maximize the overall SU throughput. A SU dynamically hops over multiple idle frequency-slots, each with an adaptive activity factor so that possible PU return in a frequency-slot may destroy only a small fraction of the SU transmission that can be recovered by erasure-correction coding. SU activity factor optimization problems are formulated to develop adaptive SU access algorithms for both centralized and distributed structures. Numerical results confirm the effectiveness and demonstrate performance gains of the proposed approach as compared to existing schemes.