Carrier frequency offset tracking algorithm for ofdma and compact mimo antenna for wireless systems

Abstract

In Orthogonal frequency-division multiple access (OFDMA), newlinecarrier frequency offset (CFO) destroys the orthogonality between subcarriers newlinedue to Doppler effect of the channel and also causes inter-carrier interference newline(ICI) as well as multiple access interference (MAI). In this work, CFO newlinetracking algorithm for OFDMA system is presented to overcome the effect of newlineICI as well as MAI. The proposed algorithm employs normalized least-mean newlinesquare (NLMS) algorithm which tracks the residual carrier frequency offset newline(RCFO) in OFDMA system. The proposed NLMS based tracking algorithm newlineuses average of all residual carrier frequency offset for improving the mean newlinesquare error (MSE) performance. The proposed NLMS based frequency newlinetracking along with frequency offset compensator improves the error newlineperformance by reducing the effect of ICI and MAI. Simulation results newlineindicate that the proposed algorithm achieves better tracking performance in newlinethe presence of frequency offset newline