WCDMA scenarios for the 2.5 GHz IMT-2000 extension band supporting asymmetric frequency allocations

WCDMA variable duplex transmission (VDT) can be used at 2.5 GHz to complement WCDMA systems currently being deployed in the IMT-2000 core band. The new 2.5 GHz IMT-2000 extension band is expected to be available for use in Europe by 2008 to provide additional resources for 3G cellular system operation. VDT will facilitate flexible use of this new spectrum in WCDMA FDD systems in a very cost competitive and spectrum efficient way for high data rate downlink biased user services. This paper describes research that has been performed in support of ITU and 3GPP contributions to show how VDT technology and the new band may be used for either WCDMA DL-only or as a combination of subbands for DL-only and paired 2.5 GHz WCDMA UL/DL. Key features of both scenarios are presented, and the required modifications to existing 3GPP WCDMA specification discussed.