Random access scheme for the ETSI/UTRA WCDMA

This paper introduces the latest random access scheme for ETSI/UTRA wideband CDMA (WCDMA) proposed for UMTS/IMT-2000. Random access transmission can be used simultaneously by multiple mobile stations for initial contact to a base station as well as for packet data transmission. A random access frame structure including preamble is presented which is very efficient with respect to the processing delay as well as data throughput. Performance results for different transmission scenarios in mobile radio environments based on simulations are discussed. Different preamble power settings with and without antenna diversity are analyzed.