A Nonlinearity Mitigation Method for a Broadband RF Front-End in a Sensor Based on Best Delay Searching.

Wen Zhao,Gang Dai,Hong Ma,Lin Hu,Jiang Jin,Hua Zhang

doi:10.3390/s17102233

Abstract

The cognitive radio wireless sensor network (CR-WSN) is experiencing more and more attention for its capacity to automatically extract broadband instantaneous radio environment information. Obtaining sufficient linearity and spurious-free dynamic range (SFDR) is a significant premise of guaranteeing sensing performance which, however, usually suffers from the nonlinear distortion coming from the broadband radio frequency (RF) front-end in the sensor node. Moreover, unlike other existing methods, the joint effect of non-constant group delay distortion and nonlinear distortion is discussed, and its corresponding solution is provided in this paper. After that, the nonlinearity mitigation architecture based on best delay searching is proposed. Finally, verification experiments, both on simulation signals and signals from real-world measurement, are conducted and discussed. The achieved results demonstrate that with best delay searching, nonlinear distortion can be alleviated significantly and, in this way, spectrum sensing performance is more reliable and accurate.

Highlights

Being capable of gathering information from the environment with simple processing, low complexity, and low power consumption, wireless sensor networks (WSN) have attracted an increasing amount of attention and have seen rapid development, especially in micro-electro-mechanical systems (MEMS) technology [1]
Since the Industrial Scientific Medical (ISM) band, where WSNs operate, is shared with various kinds of successful communication technologies [2], the detection performance in a complex electro-magnetic environment is affected by false alarms or missed detection, and inevitably degrades
Most studies regarding cognitive radio wireless sensor network (CR-WSN) in published papers focus on the development of sensing techniques [7,8,9,10,11,12,13]

Summary

Introduction

Being capable of gathering information from the environment with simple processing, low complexity, and low power consumption, wireless sensor networks (WSN) have attracted an increasing amount of attention and have seen rapid development, especially in micro-electro-mechanical systems (MEMS) technology [1]. Since the Industrial Scientific Medical (ISM) band, where WSNs operate, is shared with various kinds of successful communication technologies [2], the detection performance in a complex electro-magnetic environment is affected by false alarms or missed detection, and inevitably degrades. Instead of the traditional fixed-spectrum arrangement method, cognitive radio (CR) has the ability to sense underutilized or unutilized bands [3] to increase the spectrum efficiency to some extent. CR-WSN is supposed to be a promising technique, taking into account both spectrum sensing accuracy and efficiency [4,5,6].

Objectives

Methods

Results