Reciprocally-Benefited Secure Transmission for Spectrum Sensing-Based Cognitive Radio Sensor Networks.

Dawei Wang,Yichen Wang,Li Sun,Pinyi Ren,Qinghe Du

doi:10.3390/s16121998

Abstract

The rapid proliferation of independently-designed and -deployed wireless sensor networks extremely crowds the wireless spectrum and promotes the emergence of cognitive radio sensor networks (CRSN). In CRSN, the sensor node (SN) can make full use of the unutilized licensed spectrum, and the spectrum efficiency is greatly improved. However, inevitable spectrum sensing errors will adversely interfere with the primary transmission, which may result in primary transmission outage. To compensate the adverse effect of spectrum sensing errors, we propose a reciprocally-benefited secure transmission strategy, in which SN’s interference to the eavesdropper is employed to protect the primary confidential messages while the CRSN is also rewarded with a loose spectrum sensing error probability constraint. Specifically, according to the spectrum sensing results and primary users’ activities, there are four system states in this strategy. For each state, we analyze the primary secrecy rate and the SN’s transmission rate by taking into account the spectrum sensing errors. Then, the SN’s transmit power is optimally allocated for each state so that the average transmission rate of CRSN is maximized under the constraint of the primary maximum permitted secrecy outage probability. In addition, the performance tradeoff between the transmission rate of CRSN and the primary secrecy outage probability is investigated. Moreover, we analyze the primary secrecy rate for the asymptotic scenarios and derive the closed-form expression of the SN’s transmission outage probability. Simulation results show that: (1) the performance of the SN’s average throughput in the proposed strategy outperforms the conventional overlay strategy; (2) both the primary network and CRSN benefit from the proposed strategy.

Highlights

Wireless sensor networks have been identified as a promising technology for the ongoing developing intelligent world and are widely deployed for different application fields, such as military, environmental monitoring [1], healthcare [2], smart home [3] and other commercial areas [4]
The license-exempt industrial, scientific and medical (ISM) bands are crowded with other communication systems, such as WiFi, wireless local area networks (WLANs), Bluetooth, etc. [7]
We investigate the effects of the spectrum sensing time, target detection probability and the primary users (PU)’ secrecy outage probability on the sensor nodes (SN)’s average throughput

Summary

Introduction

Wireless sensor networks have been identified as a promising technology for the ongoing developing intelligent world and are widely deployed for different application fields, such as military, environmental monitoring [1], healthcare [2], smart home [3] and other commercial areas [4]. Thousands of sophisticated, overlapping and coexisting wireless sensor networks burden the limited licensed spectrum, where sensor nodes (SN) suffer from strong interference. The secondary system can share the licensed spectrum through underlay or overlay modes. For the underlay spectrum sharing mode, the secondary network accesses the licensed spectrum concurrently with the transmission of the primary network under the interference temperature constraint. For the overlay spectrum sharing mode, the secondary system detects the unutilized licensed spectrum (known as white space) to access and avoids interference to the primary network. As a promising spectrum sharing approach, the overlay mode, which improves the throughput of the secondary network, and guarantees the quality of service (QoS) requirement of the primary network, will be adopted in this paper. Since the inevitable spectrum sensing errors will result in the performance degradation of both the primary and secondary networks, the network parameters should be carefully designed to improve the spectrum sensing accuracy [10]

Results

Discussion

Conclusion