Patent ID: 7400872
Filing Date: 2008-07-15
Classification: H04B

Abstract:
1. A radio receiving apparatus comprising: a plurality of antennas; a switcher for switching signals received by said plurality of antennas; a first selection controller for comparing correlation values for in-phase/quadrature components contained in the received signals to select one of said plurality of antennas, and controlling said switcher; and a second selection controller for measuring a strength of the received signals as indices, and for controlling a selection of said plurality of antennas in diversity receiving, and for controlling a start-up of said first selection controller, wherein said second selection controller comprises a filter for filtering the received signals supplied for averaging the received signals at levels of sensitivity different from each other; said filter comprising: a first filter for raising the sensitivity in the filtering to output a received signal having a property approximately same as a property of the received signals supplied; a second filter for reducing the sensitivity lower than the sensitivity of said first filter to output an averaged received signal; a start-up generator on a basis of an output from said first filter for generating the first start-up signal for enabling measurement of the indices for the strength of the signals; a holding circuit for holding the received signals supplied from said second filter for the respective antennas; a determination controller for generating switching of said plurality of antennas, according to whether or not a predetermined condition is satisfactory, on a basis of the received signals held during a period for which the first start-up signal is outputted, and determining the selection of the antennas; and a determining circuit for determining, on a basis of comparison of the received signals supplied through said second filter after determination of the antennas with a predetermined threshold value, whether or not the received signals are erroneously detected; said determination controller generating a signal for resetting to said start-up generator and said holding circuit, and a second start-up signal for starting up said second selection controller on a basis of determination of erroneous detection.