The Smart Antenna WCDMA IMT-2000 Testbed

摘要

The smart antenna WCDMA IMT-2000 system (SWS) is developed based on three function groups -service resource, service control, and service management groups. The SWS functions, in this paper, are defined as the functions required for the SWS operations. In order to test all these functions efficiently, ETRI developed a testbed for the SWS. In this paper, we discuss the SWS testbed architecture from the point of view of implementing the SWS functions. In the testbed, the commercial user equipment (UE) handsets are used. Therefore, This paper is mainly concerned with implementing the radio access network (RAN). A cell of the SWS consists of 3 sectors to easily cooperate with the existing WCDMA IMT-2000 system. A sector has antenna array system of 8 antenna elements, which makes maximum 12 beams. The propagation characteristics differences among paths between antenna element and transceiver are calibrated in the system. For the down link from Node-B to UE, the beam-form is fixed, while for the up link from UE to Node-B, the beam is formed adaptively to the dynamically changing environment. The SWS follows the Uu interface of the 3GPP specifications. Services supported are such circuit services (CSs) as voice of 12.2kbps and H.263 video of 384kbps. The power control techniques of open loop and closed loop are adopted and the softer and soft handoffs are supported.