Patent ID: 6351238
Filing Date: 2002-02-26
Classification: G01S

Abstract:
A direction of arrival (hereinafter recited as DOA) estimation apparatus comprising:an array antenna using a plurality of antenna elements; a plurality of frequency converters that frequency convert and phase detect respective high frequency signals obtained from respective antenna elements of said array antenna and output a complex base band signals; a plurality of A/D converters that converts a plurality of complex base band signals output from said plurality of frequency converters to respective complex digital signals; a plurality of low pass filters that output respective complex low frequency signals with attenuated high frequency components of complex digital signals converted by said plurality of A/D converters; a plurality of down samplers that output complex signals respectively, said complex signals are down sampled by down sampling and multiplied by integral number of sampling interval of said A/D converter, said complex low pass signal generated from said plurality of low pass filters; a data transfer section that accumulates said plurality of complex down sampled signals obtained from respective said antenna elements and transfers the data; and a DOA estimation processing section that estimates an arrival direction of wave based on data output from of said data transfer section.