Smart antenna concepts for time-slotted CDMA

Currently, smart antenna concepts for mobile radio systems applicable at the base station (BS) are subject to worldwide research activities. Taking advantage of the directional inhomogeneity of mobile radio channels, the application of smart antenna concepts in cellular mobile radio is expected to increase the admissible number of users and to decrease both the cluster order, i.e. the number of cells per cluster, and the transmission powers. Three different approaches to smart antenna concepts applying receiver antenna diversity at the uplink receiver with different antenna configurations are investigated for a time-slotted CDMA mobile radio system termed joint detection CDMA (JD-CDMA). In order to quantify the obtainable performance improvements, the spectral efficiency, which measures the information rate per unit bandwidth and per cell, is considered. The paper describes a method to determine said spectral efficiency by means of simulations. This method is applied to the uplink of a JD-CDMA mobile radio system explicitly taking the three aforementioned smart antenna concepts into account