Adaptive antenna arrays for cellular CDMA communication systems

The use of an adaptive antenna array at the base station in the reverse link of cellular communication systems is proposed. Two kinds of adaptive methods are considered. First, the recursive least squares (RLS) algorithm, which is a reference signal based method, is used to adjust the weight coefficients of the array. For eigenstructure based methods, the ESPRIT algorithm is used for angle of arrival (AOA) estimation and the linear least squares estimate (LLSE) is used to determine the adaptive array weights. The improvement in performance is quantified by comparison with the omnidirectional antenna system using realistic simulations. The comparisons of different adaptive arrays are discussed and analyzed.