On the feasibility of a 2-Mb/s bearer service in a future cellular radio system using code-division multiple access

The universal mobile telecommunications system (UMTS) and other third-generation mobile radio systems will be required to support data rates up to 2 Mb/s. This paper examines whether a direct-sequence spread-spectrum air interface can support such a high data rate in an outdoor environment. A mathematical analysis of the operation of a RAKE receiver is presented. Monte-Carlo methods are used to establish the probability that a 2-Mb/s link is possible and the proportion of system capacity such a link would consume. It is concluded that with sufficiently complex RAKE receivers and a high enough chip rate, it is certainly practical for a direct-sequence code-division multiple-access (DS-CDMA) mobile radio system to offer a 2-Mb/s service and that the overall spectrum efficiency will be high provided that the majority of users of the system use much lower data rates.