Patent ID: 6647276
Filing Date: 2003-11-11
Classification: H01Q,H04B,H04W

Abstract:
A radio base station apparatus provided with an array antenna having a plurality of antenna elements, wherein:a receive signal calibration system of said radio base station apparatus comprises: a receive probe signal spreading unit which spreads a specific code series with a specific spread code; a power control unit which performs power control on an output signal of said receive probe signal spreading unit; a D/A converting unit for the receive probe signal, for converting an output signal of said power control unit from a digital signal to an analog signal; a probe signal RF unit which converts an output signal of said D/A converting unit to a radio frequency and performs power control on said radio frequency; a coupling unit which adds said probe signal to receive signals received respectively by said plurality of antenna elements, so as to generate receive signals added with probe; an RF unit which converts the receive signals added with probe, which are generated in said coupling unit, to baseband signals; an A/D converting unit which converts the baseband signals generated in said RF unit to digital signals; a receive probe signal despreading unit which outputs results of despreading the signals subjected to said A/D conversion with a spread code used for the probe signal, and which outputs results of despreading said signals intentionally with a spread code that has not been used; a correlation matrix calculation unit that obtains correlation of receive probe signals between each pair of antenna elements from the output of said receive probe signal despreading unit, calculates a signal subspace from an obtained correlation matrix, and calculates phase rotation and amplitude calibration required for an eigen vector having a maximum eigen value of the signal subspace and a predetermined vector to have a specific relation with each other; and a receive signal calibration unit which performs calibration of the output signals of the A/D converting unit, with said output signals being converted from said baseband signals by the A/D converting unit, and with said calibration corresponding to said phase rotation and said amplitude calibration calculated by said correlation matrix calculation unit; and said power control unit controls power of said probe signal inputted, such that the power becomes a necessity minimum required for said correlation matrix calculation unit to calculate the correlation matrix.