Downlink intercell coordination for DS-CDMA non real time data

In supporting delay insensitive data in the DS-CDMA system, in addition to power control, by utilizing the possibility of scheduling transmissions, the interference can be efficiently mitigated. 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 paper 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 interference 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 stations 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 [P. Bender et al., 2000]; 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. Upon our simulations, we have concluded that it is possible to significantly improve the system throughput of an HDR system, by adopting the cell coordination.