FRAMES MULTIPLE-ACCESS FOR UMTS AND IMT-2000

This article presents the FRAMES multiple access (FMA) concept designe d for third-generation mobile radio systems. The concept consists of t wo modes, TDMA-based FMA1 and CDMA-based FMA2, which have been contrib uted to the standardization processes of third-generation systems. FMA 1 uses the TDMA slot structure where spreading can be applied inside t he slot or, alternatively, plain TDMA-type transmission can be used. F MA2 is a single-carrier wideband CDMA solution using a 4.096 Mchips/s basic chip rate. The FMA concept facilitates common upper-layer protoc ol structure as well as GSM backwards compatibility for evolution from second-generation systems to third-generation mobile radio systems. T he defined concept fulfills the UMTS/IMT-2000 requirements in providin g the services needed for the next millennium.