Robust Relay in Narrow-Band Communications for Ubiquitous IoT Access

Qinghe Du,Li Sun,Bo Sun,Xuelin Zhang,Nan Lu

doi:10.1155/2017/9270907

Abstract

We propose a robust wireless relay scheme in narrow-band communications for IoT access, which matches the typical features of IoT often carrying relatively low data rate with limited bandwidth. This framework is towards offering robustness in QoS guarantees with emphases on security and/or reliability, and we use the security-assured network as the typical scenario. In particular, we consider a dual-hop relay network including a transmitter, a receiver, an amplify-and-forward (AF) untrusted relay, and a jamming node. The jamming node is treated as a helper. Specifically, the jammer broadcasts artificial noise (AN), which in fact pollutes both the untrusted relay and the destination node’s signals. However, we show that such AN can be effectively mitigated after the destination node obtains the forwarded signal from the relay, while the untrusted relay node cannot do so. The core idea for robustness assurance is to exploit higher signal dimensions at the receiver over the untrusted relay node. Simulations and analyses are also conducted to demonstrate that our proposed scheme can make the performance at the untrusted relay an interference-limited manner while completely removing the interferences at the receiver, therefore corroborating our claim in robustness in terms of security and reliability.

Highlights

In the Internet of Things (IoT) vision, every physical object plays the role in both providing and consuming diverse service resources, making the wireless networks efficiently connected yet highly heterogonous [1]
We propose a simple yet robust wireless relay scheme with a coexisting jamming node for the narrow-band communications scenario
Node C will judge transmitted signal x based on the result of received signal vector y multiplied with the matrix LZF, where LZF = R−1 according to the zero forcing criterion

Summary

Introduction

In the Internet of Things (IoT) vision, every physical object plays the role in both providing and consuming diverse service resources, making the wireless networks efficiently connected yet highly heterogonous [1]. Journal of Sensors with limited wireless-connecting capability, too much information exchange and too complicated cooperation protocols are hard to implement This issue imposes the urgent needs on robust and lightweight approaches in cooperative IoT access scenarios with QoS provisioning on reliability as well as security. To address this problem, we propose a simple yet robust wireless relay scheme with a coexisting jamming node for the narrow-band communications scenario. Our proposed relay scheme with coexisting interferences can be applied in the following two typical cases towards the robustness of security and reliability provisioning, respectively, for IoT access. E(⋅) is the expectation operator, Var{⋅} denotes the variance of a random variable, and [x]+ ≜ max(0, x)

System Model

D Source

Detection Schemes at the Destination Node

Ergodic Secrecy Throughput of Three Detection Approaches

Simulation Results and Discussions

Conclusion