Distributed algorithm for dynamic spectrum access in infrastructure-less cognitive radio network

Abstract

The dynamic spectrum access (DSA) algorithms aim to maximize network throughput by ensuring orthogonal channel allocation among secondary users (SUs) in cognitive radio network (CRN). The DSA is challenging in the infrastructure-less CRN (ICRN) due to lack of coordination among SUs. Most of the existing algorithms assume prior knowledge of the number of active SUs to guarantee orthogonalization. The musical chair (MC) algorithm is the state-of-the-art algorithm where the number of SUs are unknown and estimated independently at each SU. However, MC algorithm incurs a significant number of SU collisions and hence, the aggregate throughput is poor compared to centralized algorithms. In this paper, we setup DSA in ICRN as a multi-player multi-armed Bandit problem and develop distributed algorithm which allows SUs to orthogonalize in optimal channels with a negligible number of collisions. We also develop realistic USRP based testbed to validate the performance of the DSA algorithms in the real radio environment. Experimental results validate the superiority of the proposed algorithm over existing algorithms in terms of network throughput and fairness in channel access. Furthermore, a fewer number of collisions and hence, fewer retransmissions lead to efficient use of battery power, spectrum and time.