ISSN (Online) : 2319 - 8753 ISSN (Print) : 2347 - 6710 International Journal of Innovative Research in Science, Engineering and Technology An ISO 3297: 2007 Certified Organization Volume 3, Special Issue 5, July 2014 International Conference On Innovations & Advances In Science, Engineering And Technology [IC - IASET 2014] Organized by Toc H Institute of Science & Technology, Arakunnam, Kerala, India during 16th - 18th July -2014 Copyright to IJIRSET www.ijirset.com 38 Adaptive IIR Notch Filter Design For Cancellation of Periodic Impulsive Noise in OFDM Based Power Line Communications V. Vandana Pillai 1 , S.F. Safna 2 , S.Ratheesh 3 , Shefin Shoukath 4 P.G Student, Dept of Electronics and Communication Engineering, MACE, Trivandrum , Kerala, India 1 P.G Student, Dept of Electronics and Communication Engineering, MACE, Trivandrum , Kerala, India 2 P.G Student, Dept of Electronics and Communication Engineering, MACE, Trivandrum , Kerala, India 3 Associate Professor, Dept of Electronics and Communication Engineering, MACE, Trivandrum, Kerala, India 4 ABSTRACT: This paper presents a simple and cost effective method to remove the periodic impulsive noise in power-line communications (PLC) system. In the real PLC environment, some electrical appliances will produce impulsive noise at a fixed frequency with the power spectral density (PSD) usually exceeding that of the received signals. This type of impulsive noise is the periodic impulsive noise, and it usually remains stationary over periods of minutes or even for hours. This paper deals with a simple and effective approach to remove the periodic impulsive noise before the synchronization of PLC receiver. The proposed algorithm is employed to detect the periodic impulsive noise and then suppresses the periodic impulsive noise with an adaptive infinite impulse response (IIR) notch filter before the synchronization of the system. KEYWORDS: Adaptive infinite impulse response (IIR) notch filter, Orthogonal Frequency Division Multiplexing (OFDM), Periodic impulsive noise, power-line communications. I. INTRODUCTION Unlike traditional electric grids that carry one-way flow of power from generators to customers, smart grids use two-way flows of information to create an intelligent energy delivery network. Various technologies have emerged to facilitate data communications throughout the grid, especially in two scenarios: outdoor communications between local utilities and customers, and indoor communications for home area networks [3]. Power line communications (PLC) have been attractive as a solution for smart grid communications. Power lines differ significantly in their structure and physical characteristics from usual communication mediums such as fibre optic and coaxial cables . Understanding those properties is essential for the design of PLC systems. Due to the existing power-line network infrastructure, transmitting signals over the power line will cost less than other communication approaches. The power-line network is not originally designed to transmit signals, but to supply power for all kinds of electrical appliances. So the PLC environment is full of noise which is mostly produced by the electrical appliances in the power-line networks. The noise in the PLC environment has been categorized into five general classes: colored background noise; narrowband noise; periodic impulsive noise asynchronous to the mains frequency; periodic impulsive noise synchronous to the mains frequency; and asynchronous impulsive noise. A number of modulation techniques, including single-carrier, multi-carrier and spread spectrum are of interest for PLC. Among those, orthogonal frequency division multiplexing (OFDM) stands as an excellent candidate for PLC. The basic principle of OFDM is to split high-speed data symbols into slow data streams which then modulate multiple narrowband orthogonal subcarriers simultaneously. This reduces the effect of multipath by enlarging the symbol duration