Radio receiver and electronic timepiece

Patent metadata

Field	Value
Publication number	US-9529339-B2
Application number	US-201514830449-A
Country	US
Kind code	B2
Filing date	Aug 19, 2015
Priority date	Aug 29, 2014
Publication date	Dec 27, 2016
Grant date	Dec 27, 2016

Abstract

A radio receiver receives transmitted radio waves from positioning satellites, and includes: a signal amplification unit configured to amplify a received signal; an acquisition unit configured to acquire a satellite signal from the amplified signal; and a control unit configured to obtain predetermined information from the acquired satellite signal, determine a reception condition of transmitted radio waves based on the processing condition of at least one of the obtainment and the acquisition unit, and performs operation setting of a gain of the signal amplification unit according to the determined reception condition, wherein the control unit performs the operation setting so that the gain set in the operation setting when the reception condition is determined to be a first reception condition is smaller than the gain set in the operation setting when the reception condition is determined to be a second reception condition inferior to the first reception condition.

First claim

The invention claimed is:

1. A radio receiver comprising:
a signal amplification unit configured to receive a radio wave transmitted from a positioning satellite and amplify a signal of the received transmitted radio wave;
an acquisition unit to which the signal amplified by the signal amplification unit is input, the acquisition unit being configured to acquire a satellite signal containing position information and date and time information from the signal; and
a control unit configured to obtain at least one of the position information and the date and time information from the satellite signal acquired by the acquisition unit, determine a reception condition of the transmitted radio wave based on at least one of a processing condition of the obtainment and a processing condition of the acquisition unit, and perform operation setting of a gain of the signal amplification unit according to the determined reception condition,
wherein the control unit performs the operation setting so that the gain set in the operation setting when the reception condition is determined to be a first reception condition is smaller than the gain set in the operation setting when the reception condition is determined to be a second reception condition inferior to the first reception condition, and
wherein the control unit determines the reception condition based on a number of satellite signals acquired by the acquisition unit in a predetermined acquisition period from a start of operation for the acquisition.

2. The radio receiver according to claim 1 , wherein the control unit determines the reception condition based on a number of predetermined parts identified by the control unit within a position identification time set for identifying the predetermined parts, the predetermined parts being parts in transmission formats of the acquired satellite signals and being for determination of a position in the transmission formats.

3. The radio receiver according to claim 1 , wherein the control unit calculates signal-to-noise ratios of demodulated signals, each containing one of the satellite signals acquired by the acquisition unit and being demodulated, and determines the reception condition based on results of calculation of the signal-to-noise ratios.

4. The radio receiver according to claim 3 , wherein the control unit determines the reception condition based on the number of satellite signals of the demodulated signals with calculation results of the signal-to-noise ratios being a predetermined demodulation reference value or larger.

5. The radio receiver according to claim 2 , wherein the control unit calculates signal-to-noise ratios of demodulated signals, each containing one of the satellite signals acquired by the acquisition unit and being demodulated, and determines the reception condition based on results of calculation of the signal-to-noise ratios, and
wherein when three or more of the predetermined parts for determining the position in the transmission formats of the acquired satellite signals are identified within the position identification time set for identifying the predetermined parts, the control unit determines the reception condition based on a number of satellite signals of the demodulated signals with calculation results of the signal-to-noise ratios being a predetermined demodulation reference value or larger.

6. The radio receiver according to claim 3 , wherein when three or more predetermined parts for determining a position in transmission formats of the acquired satellite signals are identified within a position identification time set for identifying the predetermined parts, the control unit determines the reception condition based on a number of satellite signals of the demodulated signals with calculation results of the signal-to-noise ratios being a predetermined demodulation reference value or larger.

7. The radio receiver according to claim 2 , wherein the control unit calculates signal-to-noise ratios of demodulated signals, each containing one of the satellite signals acquired by the acquisition unit and being demodulated, and determines the reception condition based on results of calculation of the signal-to-noise ratios, and
wherein the control unit performs the operation setting so that the gain is minimized within a range in which a number of satellite signals of the demodulated signals with calculation results of the signal-to-noise ratios being a predetermined demodulation reference value or larger is equal to or larger than a number necessary for obtaining information.

8. The radio receiver according to claim 1 , wherein the control unit determines the reception condition based on time elapsed from a last timing at which the date and time information contained in the satellite signals is obtained or based on the number of times obtainment of the date and time information is unsuccessful after the last timing.

9. The radio receiver according to claim 1 , wherein the control unit determines the reception condition from multiple predetermined levels, and performs the operation setting of the gain determined discretely for each of the levels.

10. The radio receiver according to claim 2 , wherein the control unit determines the reception condition from multiple predetermined levels, and performs the operation setting of the gain determined discretely for each of the levels.

11. The radio receiver according to claim 3 , wherein the control unit determines the reception condition from multiple predetermined levels, and performs the operation setting of the gain determined discretely for each of the levels.

12. The radio receiver according to claim 4 , wherein the control unit determines the reception condition from multiple predetermined levels, and performs the operation setting of the gain determined discretely for each of the levels.

13. The radio receiver according to claim 5 , wherein the control unit determines the reception condition from multiple predetermined levels, and performs the operation setting of the gain determined discretely for each of the levels.

14. The radio receiver according to claim 7 , wherein the signal amplification unit includes:
multiple amplification units configured to amplify an input signal; and
a switching unit configured to turn on and off each of the amplification units, and
wherein the control unit performs the operation setting by causing the switching unit to operate to select an amplification unit that amplifies a signal input to the signal amplification unit from the amplification units.

15. The radio receiver according to claim 1 , wherein the control unit performs the operation setting within a period in which parts of the satellite signals not containing the position information and the date and time information are received.

16. An electronic timepiece comprising:
the radio receiver according to claim 1 ;
a timer unit configured to count date and time; and
an electronic timepiece control unit configured to correct date and time of the timer unit by using date and time information when the date and time information is obtained by the control unit of the radio receiver.

17. A radio receiver comprising:
a signal amplification unit configured to receive a radio wave transmitted from a positioning satellite and amplify a signal of the received transmitted radio wave;
an acquisition unit to which the signal amplified by the signal amplification unit is input, the acquisition unit being configured to acquire a satellite signal containing position information and date and time information from the signal; and
a contr

Assignees

• Casio Computer Co Ltd

Inventors

• Matsue Takeshi

Classifications

• G01S19/36

  relating to the receiver frond end · CPC title

• G01S19/28

  Satellite selection · CPC title

• G01S19/34

  Power consumption · CPC title

• G04R20/04 Primary

  Tuning or receiving; Circuits therefor · CPC title

• G01S19/14

  specially adapted for specific applications · CPC title