Adaptive spectrum aggregation for opportunistic resource management in multichannel networks
Chabalala S. Chabalala, Fambirai Takawira · 2017
Spectrum aggregation (SA) is a technique through which a user performs transmission through multiple channels to maximize capacity. In this paper, adaptive SA with optimal channel selection and power allocation for multiuser multichannel access in spectrum sharing wireless networks is proposed. The main objective is to maximize secondary user (SU) nodes capacity subject to: quality-of-service (QoS) requirements on capacity, collision probability threshold to protect primary user (PU) services, SU transit power and the fading wireless channels. This allows multiple SU nodes to dynamically aggregate PU channels without degrading performance of the PU nodes. Convex relaxation is employed to develop a relaxed optimal solution for the otherwise a mixed integer nonlinear programming (MINLP) problem, from which branch-and-bound (BnB) technique is employed to develop the optimal solution for the original MINLP problem. Furthermore, a suboptimal SA scheme with less complexity is developed based on the Hungarian algorithm. The presented simulation results reveal significant performance improvement for the proposed SA schemes in terms of capacity, outage probability and collision probability.