Patent ID: 6185440
Filing Date: 2001-02-06
Classification: H01Q,H04B,H04W

Abstract:
A method for transmitting a downlink signal from a communication station to one or more subscriber units, the communication station including an array of antenna elements, each antenna element coupled to an associated transmit apparatus having an input and an output, the coupling of each antenna element being to the output of its associated transmit apparatus, the associated transmit apparatus inputs coupled to a signal processor, the method comprising:for each particular signal processing procedure of a set of different signal processing procedures, each of the signal processing procedures being for processing the downlink signal to form a plurality of processed downlink antenna signals, each of the signal processing procedures including weighting the downlink signal in phase and amplitude according to a corresponding weight vector, each processed downlink antenna signal having an intended antenna element in the array, repeating the steps of:(a) processing the downlink signal according to the particular signal processing procedure to form a particular plurality of processed downlink antenna signals;(b) transmitting the downlink signal by passing each processed downlink antenna signal of the particular plurality of processed downlink antenna signals to its intended antenna element through the intended antenna element's associated transmit apparatusthe set of different signal processing procedures designed to achieve a desirable radiation level at any location in the complete range of azimuths of the antenna array during at least one of the repetitions of step (b) of transmitting,each corresponding weight vector used for weighting in each different processing procedure being a different weight vector of a sequence of different weight vectors, the weighting according to each corresponding weight vector producing the plurality of processed downlink antenna signals, the sequence of weight vectors designed to achieve a desirable radiation level at any location in a desired sector during at least one of the repetitions of step (b) of transmitting.