Selective Sensing and Access Strategy to Maximize Throughput in Cognitive Radio Sensor Network

Weijun Li,Yuli Fu,Beihai Tan,Zhenquan Wu,Chao Yang

doi:10.1155/2014/749739

Abstract

This paper presents a selective spectrum sensing and access strategy in a cognitive radio sensor network (CRSN), in order to maximize the throughput of secondary user (SU) system. An SU senses multiple channels simultaneously via wideband spectrum sensing. To maximize the throughput and reduce the sensing energy consumption, not all of the channels are sensed. The SU selects some channels for spectrum sensing and accesses these channels based on the sensing results. The unselected channels are accessed directly with low transmission power. A selection making algorithm based on partially observable Markov decision process (POMDP) theory is proposed, to make the SU determine which channels are selected for sensing, how long the sensing time, and the transmission powers of channels. An optimal policy and a myopic policy are proposed to solve the proposed POMDP problem. Moreover, an optimization problem is proposed to solve the synchronism problem among the selected channels. Numerical results show that the proposed selective spectrum sensing and access strategy improves the system performance efficiently.

Highlights

Wireless sensor networks (WSNs) play a critical role in many research areas, such as machine-to-machine network (M2M), emergency communication, and smart home [1,2,3,4]
In the cognitive radio sensor network (CRSN), the wireless nodes are defined as secondary users (SUs), while the other available spectrum owners are defined as primary users (PUs)
Different from the excessive spectrum sensing and access researches, which focus on utilizing the time or space domain only, a spectrum sensing and access strategy of CRSN is proposed in this paper, in which an SU system uses the available spectrum both in time and space domains in multiple channels

Summary

Introduction

Wireless sensor networks (WSNs) play a critical role in many research areas, such as machine-to-machine network (M2M), emergency communication, and smart home [1,2,3,4]. Different from the excessive spectrum sensing and access researches, which focus on utilizing the time or space domain only, a spectrum sensing and access strategy of CRSN is proposed in this paper, in which an SU system uses the available spectrum both in time and space domains in multiple channels. When the channel is sensed as idle, the SU accesses it with a higher transmission power; the available spectrum in time domain is used. Under the selection making algorithm, the SU determines which channels are selected for spectrum sensing, how long the sensing time, and the transmission powers of the accessed channels. The objective of the selection making algorithm is to maximize the throughput of SU system, while avoiding unacceptable interference to PUs. An optimal policy and a myopic policy are derived to solve the formulated POMDP problem.

Related Work

System Model

Selection Making Algorithm

POMDP Framework

Numerical Results