A CDMA‐based radio interface for third generation mobile systems

Abstract

This paper deals with the use of a CDMA-based radio interface in third generation mobile systems (Universal Mobile Telecommunications System – UMTS, and Future Public Land Mobile Telecommunications System – FPLMTS). The paper is not intended as a detailed analysis of the radio interface performance, but as an overview of the main issues arising in a typical CDMA-based mobile system, discussing the different available technical solutions. First of all, the basic requirements of the radio interface in a third generation mobile system are outlined. In particular, the support of variable bit rate transmission, the adaptability to the different propagation and service environments and the flexibility are felt to be important topics to be discussed. Then, the main characteristics of the CDMA access technique are depicted, in relation with the above mentioned requirements, focusing in particular on the DS-CDMA radio interface designed within the RACE II – CODIT Project. In that context the paper describes some of the technical solutions proposed for the provision of advanced features such as macrodiversity, multibearer transmission and variable bit rate services.