Capacity enhancement for CDMA systems through adaptive cell sectorization

We consider the problem of adaptive cell sectorization in a CDMA system. Specifically, given the user distribution in a cell, we investigate the two problems of how to appropriately sectorize the cell such that we minimize the total received power and the total transmit power spent by all the users, in both cases, while giving each user acceptable quality of service. The optimum arrangement equalizes the number of users in each sector for the received power optimization problem. The transmit power optimization can be formulated as a graph partitioning problem which can be solved in polynomial time. In both cases, the optimum arrangement can be quite different from uniform cell sectorization (equal partitioning) under non-uniform traffic conditions. We observe that, with adaptive sectorization, received and transmit power savings are achieved and the number of users served by the system (system capacity) is increased compared to uniform sectorization of the cell.