An Efficient Subcarrier and Power Allocation Scheme for OFDM based Cognitive Radio Networks Considering Channel Sensing Errors

Abstract

Cognitive radio plays a major role in today’s wireless communications and solves the spectrum scarcity problem by efficiently utilizing the vacant spectrum. Most CR systems employ OFDM as a modulation technique because of its flexibility in allocating spectrum resources. Allocation of vacant spectrum to the secondary users introduces interference to the primary users. In this paper, subcarrier and power allocation for OFDM based cognitive radio network for joint overlay and underlay spectrum access mechanism (JOUSAM) with channel sensing error is proposed. For such a CR systems, the transmission rate is maximized for a given power budget, while keeping the interference level of the primary user below a certain threshold. The numerical results show that the proposed scheme achieves higher transmission rate when compared to system without considering sensing error.