HCR-WSN: Hybrid MIMO cognitive radio system for wireless sensor network

Abstract

Multi Input Multi Output (MIMO) based Cognitive Radio (CR) provisions an efficient utilization of the scarce electromagnetic spectrum. Traditional CR includes Interweave and Underlay techniques. We propose a Hybrid MIMO CR system for Wireless Sensor Network, HCR-WSN, that utilizes both underlay and interweave CR techniques and provides higher spectral efficiency. The wireless sensor network consisting of CR nodes achieves higher throughput using the proposed framework.HCR-WSN improves the spectral efficiency gain of an Uplink Hybrid Cognitive Radio MIMO system in wireless sensor network (WSN), by implementing Narrowband and Wideband (Multiple Carrier Direct Sequence Code Division Multiple Access, i.e., MC-DS-CDMA) technology adhering to the Interference Threshold limit. The WSN is consisting of nodes acting as primary users (PU) and CR secondary users (SU). The proposed Hybrid CR system ensures efficient spectral utilization under circumstances resulting in near zero throughput for SU. In the presence of PU, CR-SU transmits in either Narrowband or MC-DS-CDMA based on the proposed transmission selection algorithm. In the absence of PU, SU uses Interweave technique thereby allowing other competing SUs to transmit in Interference Alignment underlay mode in a multi-user scenario. The achievable throughput is enhanced using the proposed technique in a multi-user hybrid MIMO cognitive radio wireless sensor network.