Patent ID: 7564407
Filing Date: 2009-07-21
Classification: H01Q,H04B

Abstract:
1. An array antenna directivity control apparatus which changes directivity of a plurality of antennas by updating adaptively a weighting coefficient with respect to a signal of each of the antennas, said array antenna directivity control apparatus comprising: an error calculator which calculates an error between the antenna signal and a known reference signal; weighting coefficient updating means which updates the weighting coefficient based on the error calculated by said error calculator; and update amount correcting means which corrects the weighting coefficient calculated by said weighing coefficient updating means based on predict error information predicted on the basis of the error calculated in past by said error calculator, wherein said update amount correcting means comprises: a predict error information calculator which obtains the predict error information based on differences among a plurality of the errors in past; and an adder which performs the correction by means of adding the predict error information obtained by said predict error information calculator to the weighting coefficient updated by the weighting coefficient updating means, said predict error information calculator comprising: an error history holder which holds a plurality of the errors corresponding to a plurality of historical steps, respectively; a first calculator which calculates and stores a plurality of primary difference values, each of which is calculated based on two consecutive errors of the plurality of the error stored by said error history holder; and a second calculator which calculates and stores an average of the plurality of primary difference values stored in said first calculator, as the predict error information, and output the average to said adder.