Downlink intercell coordination for DS-CDMA non real time data

Abstract

In DS-CDMA system, in addition to power control, by utilizing the possibility of scheduling transmissions, the interference can be efficiently migrated. In the previous study on transmission scheduling, a common issue was when to combine time division with CDMA in order to maximize the system throughput while minimizing power consumption. A key question in this thesis is how to manage intercell interference in the CDMA downlink. For the purpose, we have derived a generic condition that tells when to use time division. We applied this condition to the intercell inference management, which we call cell coordination. With cell coordination, when a base station reaches the turn of a predefined mobile, all the other coordinated base situations are temporarily shut down until this mobile finishes its transmission. We have compared capacity difference between with- and without- cell coordination. One important application of this work can be found in the High Data Rate (HDR) system [10]. Based on our result, we propose the cell coordination region (CCR) for HDR, which has a similar concept to the soft handoff region, but now CCR is for HDR where soft handoff may not be supported.