Parametric sensitivities of 3G UTRA cellular system

Abstract

Technologies of the third generation (3G) mobile radio system are expected to be standardized by the end of year 1999. Support of multimedia services and multirate date transmission are some of the many attractive features of the 3G systems. Universal Terrestrial Radio Access (UTRA) system, which is based on wideband CDMA, is considered to be a leading candidate for standardization. In this thesis, the parametric sensitivities of 3G UTRA cellular system are investigated. The essence of a Rake receiver in mobile radio channel is discussed with simulation results. The number of fingers in the Rake receiver is one of the parameters investigated. Situations when the number of fingers is matched (and unmatched) to the number of signal paths in the channel are investigated. The performance gain obtained by the use of path searching algorithm in an unmatched Rake receiver is shown and compared with theoretical analysis. Sensitivities of the UTRA system performance to the parameters interlaying depth and Doppler frequency are studied. Antenna diversity used as another means to combat fast fading in order to improve the system performance is also discussed. Performance results are given for two kinds of diversity technique, which are bit error based antenna diversity and post-detection antenna diversity. Power control is essential in CDMA systems and the situations when imperfect power control happens on the desired user and on other user are investigated with simulation results.