New Techniques to Suppress the Sidelobes in OFDM System to Design a Successful Overlay System

Abstract

In orthogonal frequency division multiplexing (OFDM) systems the reduction of out-of-band radiations is an essential topic. To design a successful OFDM based overlay systems, it is important to reduce the sidelobes in OFDM systems. In this paper we consider three approaches: Subcarrier weighting (SW) which is based on the multiplication of the used subcarriers with real-valued
weighting factors, second approach we consider is multiple choice sequence (MCS) which is based on producing set of sequences and selecting the one sequence which has lowest power in sidelobes and third approach we consider is the conventional windowing of OFDM signal in time domain. We combine MCS with windowing technique and SW with windowing technique. Simulation results show that by combining MCS with windowing technique and SW with windowing technique, the out-of-band