Indian Journal of Science and Technology

Abstract

Objective: This paper focuses on the Bit Error Rate (BER) performance of IEEE 802.15.4 RF Zigbee transceiver compliant WSN in an interference environment. This includes 1. Studying of effect of various building materials and partitions in an indoor environment and 2. Effect of interference that coexist in an outdoor environment. Methods/Statistical Analysis: In an indoor environment, building materials such as hard board, concrete wall and the partitions of two floors are considered for the analysis. Path loss due to those materials in an indoor environment is calculated by log-distance model. Improved Gaussian Approximation (IGA) technique is used to derive the closed form expression for BER considering less number of interferers in a Rayleigh fading outdoor environment. BER are analysed by varying the IEEE 802.15.4 standard specific physical layer parameters, such as number of bits in a Zigbee symbol, number of modulation levels used in an OQPSK modulator and spreading length of PN sequence. Findings: The analysis in an indoor environment points out that, path-loss provided by hard board and concrete wall to the signal is equal. In case of floors, path-loss value get increased as number of floors increases between transmitter and receiver. In outdoor environment, it is analysed that BER performance of Zigbee transceiver shows better performance when lower number of bits in a Zigbee symbol and lower level of modulation scheme in OQPSK modulator. Application/Improvements: The performance can be improved by using chaotic sequence for spreading in place of PN sequence and can be implemented for IoT based applications.
Keywords: Bit Error Rate, IEEE 802.15.4, Improved Gaussian Approximation, Rayleigh, Signal to Noise Ratio, Wireless Sensor Network, Zigbee