Energy-efficiency of dual-switched branch diversity receiver in wireless sensor networks

In this paper, we develop an analytical energy efficiency model using dual switched branch diversity receiver in wireless sensor networks in fading environments. To adapt energy efficiency of sensor node to channel variations, the optimal packet length at the data link layer is considered. Within this model, the energy efficiency can be effectively improved for switch-and-stay combiner (SSC) receiver with optimal switching threshold. Moreover, to improve energy efficiency, we use error control of Bose-Chaudhuri-Hochquengh (BCH) coding for SSC-BPSK receiver node compared to one of non-diversity NCFSK receiver of sensor node. The results show that the BCH code for channel coding can improve the energy efficiency significantly for long link distance and various values of high energy consumptions over Rayleigh fading channel.

I. Introduction

The emergence of wireless sensor networks (WSNs) has currently become increased with wide-ranging applications from health, home, and environmental to military, space and commercial. They are a special case of ad-hoc wireless networks where the constraints on resources are especially tight [1]. WSNs are composed of nodes typically powered by batteries, for which replacement or recharging is very difficult. With finite energy, a finite amount of information can only be transmitted. Therefore, minimizing the energy consumption for data transmission becomes one of important design considerations for WSN in most application scenarios. Moreover, the channel fading has also a great effect on the reliability of data transmission and energy consumption in WSN. As a result, the design of energy efficient strategies to prolong lifetime or minimize the energy consumption is still of utmost and critical importance issue in WSN design [2]–[3].