Further results on adaptive CDMA cell sectorization with linear multiuser detection

We consider the adaptive sectorization problem for a CDMA system under the imperfect directional antenna. Specifically, given the number of sectors and terminal locations, and assuming base station employs linear multiuser detection, we investigate how to appropriately sectorize the cell, such that the total transmit power is minimized, while each user has an acceptable quality of service. We observe uplink/downlink duality under the assumption of matched filter and perfect antenna response. We also investigate adaptive sectorization problem in the more realistic scenario of imperfect directional antenna response. We employ MMSE power control to suppress both the intrasector interference and the intersector interference. As the optimum solution for arbitrary signature sets may have high complexity, we propose simpler suboptimum methods. The results suggest that by intelligently combining adaptive cell sectorization, power control and temporal linear multiuser detection, we are able to increase the uplink user capacity of the cell. We provide numerical results showing the robustness of optimum sectorization against Gaussian channel estimation error.