Cellular interference control for integrated services over CDMA

The advantages of CDMA for cellular voice have become well known. CDMA permits simplification in channel reuse, relying on interference averaging from a large number of distributed voice users. Due to this interference averaging property, CDMA simply translates voice activity factor and antenna sectorization into capacity gains. In this paper we address the problem of providing higher data rate packet mode service over CDMA while minimizing the required changes to the IS-95 physical layer. We propose a demand assigned burst access control mechanism that manages load and interference from the high data rate users. Based on computation of in-cell and out-of-cell interference caused by a single high rate data user, algorithms have been designed to allow burst access at rates up to M (four or more) times the full rate. We present a class of algorithms based on load information in the cell and its neighbors, pilot measurements at the mobile and burst coordination among neighbor cells. Some preliminary tradeoffs are presented. Detailed performance studies will be reported in a future paper. While the focus here is on providing higher data rates to one or more users without major changes to the IS-95 layer, the burst access controls developed will be useful in other situations as well. For example, future wideband CDMA systems may use such controls to provide even higher data rates or support more high rate users.