Patent ID: 8000673

Claim:
A diversity receiving device, comprising: a plurality of antennas which receives a radio signal respectively; a plurality of radio demodulating portions which demodulates each of radio signals received by the plurality of antennas respectively; a plurality of decoding portions which decodes output signals from the plurality of radio demodulating portions respectively; a synthesizing portion which synthesizes output signals from the plurality of decoding portions; a power-supply controlling portion which applies an ON/OFF-control to respective power supplies of the plurality of radio demodulating portions, the plurality of decoding portions, and the synthesizing portion respectively; a receiving rate calculating portion which calculates a receiving rate from an output signal of the synthesizing portion; a received quality calculating portion which calculates a received quality based on respective output signals of the plurality of decoding portions or the output signal of the synthesizing portion; and a receiving scheme switching portion which switches a receiving mode between a single reception and a diversity reception based on a receiving scheme switching threshold, updating the receiving scheme switching threshold based on the receiving rate calculated by the receiving rate calculating portion, switching the receiving mode into the single reception in which one portion of the plurality of antennas, one portion of the plurality of radio demodulating portions, and one portion of the plurality of decoding portions are employed respectively and turning OFF respective power supplies of remaining antennas, remaining radio demodulating portions, and remaining decoding portions when the received quality calculated by the received quality calculating portion exceeds the receiving scheme switching threshold, and switching the receiving mode into the diversity reception in which the plurality of antennas, the plurality of radio demodulating portions, and the plurality of decoding portions are employed respectively when the received quality is below the receiving scheme switching threshold.