Performance Analysis of Direct Sequence CDMA Power Line Communication Systems over the Frequency Selective Channel

Abstract

Outdoor power line communications (PLC) systems represent an additional and alternative for classical and communications. In this dissertation an analytical model of Direct Sequence CDMA power line communications systems has been developed for frequency-selective fading channel based on .the concepts of wireless communication. Binary phase shift keying (BPSK) modulation scheme is considered. The fading in power line is considered to follow Rayleigh distribution. During the analysis it is considered that power line channel can carry frequencies from I to 21.48 MHz (bandwidth occupation 20.48 MHz) and the chip rate would be 10.24 Mchips/s for DS-CDMA. The current research of power line channel modeling has been concentrated on home automation, broadband indoor communications and broadband data transfer in a low voltage distribution network between home and transformer station. A frequency selective multipath channel is modeled whose path gain is found to be Rayleigh distributed. A noise term has been introduced in the developed model, which consists of all type of noises in power line. To estimate impulse noises the statistical probability density functions have been used. On the basis of the analytical model, the performance of the DS-CDMA technique has been evaluated. The impact of power line noise and multipath propagation on signal to interference ratio (SIR) and bit error rate (BER) are then analyzed under various conditions. The performance parameters are evaluated as a function of number of simultaneous users.PLC with DS-CDMA is found to be a promising option for future telecommunication in a LAN and MAN.