JP2009253321A - Time information apparatus, receiver, electronic appliance, and receiving method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten time spent for knowing the size of frequency of a local oscillation signal needed to obtain a receiving signal and to reduce power consumption. <P>SOLUTION: The receiver includes: a local oscillator for changing frequencies of a local oscillation signal at a time, generating a local oscillation signal, and outputting voltage corresponding to the size of the frequency of the local oscillation signal; a mixer for mixing a receiving signal with the local oscillation signal; a band filter for passing a signal having a prescribed frequency; a detector circuit for detecting whether or not the signal whose frequency has been converted by the mixer passes the band filter; and a control circuit for recognizing that the frequency of the local oscillation signal corresponding to a voltage which occurs when it is informed that the receiving signal has been obtained from the detector circuit is necessary to obtain the receiving signal and instructing the local oscillator to keep generating local oscillation signals having the frequency. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a receiving device such as a time information device for adjusting time such as a clock, an electronic device having the receiving device, and the time information device, the receiving device, and a receiving method used in the electronic device.

The frequency of the high-frequency signal _SRF received from the transmission device (not shown) is unknown in relation to changing the main configuration “frequency of the local oscillation signal” described in Patent Document 1 below. In the local oscillator LO in the conventional receiving device R10 shown in FIG. 3, as shown in FIG. 4, the control voltage _VCNT for controlling the oscillation operation of the voltage controlled oscillator VCO is set to, for example, the voltage VA. After a while, the local oscillation signal _SLO becomes stable at the frequency _fVA , and then the mixer M
IX mixes the high frequency signal S _RF with the local oscillation signal S _LO of frequency f _VA . After mixing,
Detection circuit DET determines whether it was possible by the local oscillation signal S _LO of the frequency f _VA captures a high-frequency signal S _RF (reception).

If it is determined that it cannot be captured, the local oscillator LO converts the control voltage V _CNT to the voltage V
Changed from A to voltage VB, in the same manner as described above, performs a high-frequency signal S _RF mixer MIX is after the local oscillation signal S _LO is stabilized frequency f _VB, mixing with the local oscillation signal S _LO frequency f _VB . After mixing, the detection circuit DET generates a high frequency signal S _RF by means of the local oscillation signal S _LO of the frequency f _VA.
It is determined whether or not it was able to be captured. Thereafter, until the local oscillator LO can know the magnitude of the frequency f _LO of the local oscillation signal S _LO necessary for capturing the high-frequency signal S _RF , the local oscillator _LO reduces the control voltage V _CNT to the voltage VC → control voltage. VD → control voltage VE → control voltage VF → control voltage VG.

JP 2002-217768 A

However, in the conventional receiver R10, the control voltage time to frequency f _LO of the local oscillation signal S _LO is stabilized after changing the V _CNT (lock time LU), since it must wait, the high frequency signal S _RF needed to capture, takes much time until it is possible to find out the magnitude of the frequency of the local oscillation signal S _LO, as a result, there is a problem that power consumption increases.

  The present invention is realized by the following application examples in order to solve the above-described problems.

[Application Example 1]
A local oscillator that generates the local oscillation signal by changing the frequency of the local oscillation signal within a frequency range that is expected to capture the received signal and outputs a voltage corresponding to the magnitude of the frequency of the local oscillation signal. When,
A mixer that converts the frequency of the received signal by mixing the received signal and the local oscillation signal;
A bandpass filter that passes a signal having a predetermined frequency;
A detection circuit for detecting whether or not the signal whose frequency has been converted by the mixer has passed through the bandpass filter in order to determine whether or not the received signal could be captured;
Recognizing that the frequency of the local oscillation signal corresponding to the voltage is necessary to capture the received signal when receiving the fact that the received signal has been captured from the detection circuit, And a control circuit that instructs the local oscillator to continue generating a local oscillation signal having the frequency.

[Application Example 2]
An electronic apparatus comprising the receiving device according to Application Example 1.

[Application Example 3]
The frequency of the local oscillation signal is generated by changing the frequency of the local oscillation signal at a stroke within the range of frequencies expected to be able to capture the reception signal on which the time information is superimposed, and the frequency of the local oscillation signal is A local oscillator that outputs the corresponding voltage;
A mixer that converts the frequency of the received signal by mixing the received signal and the local oscillation signal;
A bandpass filter that passes a signal having a predetermined frequency;
A detection circuit for detecting whether or not the signal whose frequency has been converted by the mixer has passed through the bandpass filter in order to determine whether or not the received signal could be captured;
Recognizing that the frequency of the local oscillation signal corresponding to the voltage is necessary for capturing the received signal when receiving the fact that the received signal has been captured from the detection circuit, A time information device comprising: a control circuit that instructs a local oscillator to continue generating a local oscillation signal having the frequency.

[Application Example 4]
Local oscillation that generates the local oscillation signal by changing the frequency of the local oscillation signal within a frequency range that is expected to capture the received signal and outputs a voltage corresponding to the magnitude of the frequency of the local oscillation signal Process,
A mixing step of converting the frequency of the received signal by mixing the received signal and the local oscillation signal;
A band-pass filtering process for passing a signal having a predetermined frequency;
A detection step of detecting whether the signal whose frequency has been converted by the mixing step has passed through the band-pass filtering step in order to determine whether or not the received signal has been captured;
Recognizing that the frequency of the local oscillation signal corresponding to the voltage is necessary to capture the received signal when receiving the fact that the received signal was captured from the detection step, And a control step of instructing to continue generating a local oscillation signal having the frequency in the local oscillation step.

Application example 1 receiving device, application example 2 electronic device, application example 3 time information device, and application example 4
According to this reception method, the local oscillation signal is generated by changing the frequency of the local oscillation signal at once within a frequency range where the reception signal is expected to be captured. Since there is no need to wait for the period until the local oscillation signal becomes stable (lock-up time) each time the frequency of the signal is changed, the frequency of the local oscillation signal necessary to capture the received signal is The time required to learn can be shortened compared to the past,
Thereby, power consumption can be reduced as compared with the conventional case.

  A time information device according to an embodiment will be described with reference to the drawings.

<Constitution>
FIG. 1 shows a configuration of a time information device according to the embodiment. The time information device D1 of the embodiment is, for example,
In order to function as a receiver that corrects the time (adjusts the current time) within an electronic device such as a mobile phone,
As shown in FIG. 1, an antenna ANT, a low noise amplifier LNA, a mixer MIX, a bandpass filter BPF, an amplifier AMP, a detection circuit DET, a first AD converter ADC1,
A demodulating circuit DEM, a control circuit CONT, and a local oscillator LO are included.

The antenna ANT is transmitted from an opposing transmission device (not shown).
In order to receive a high-frequency signal S _RF including information for correctly adjusting the current time (frequency f _RF ), for example, a loop antenna, a slot antenna, and the like are included.

Low-noise amplifier LNA amplifies the RF signal S _RF in order to the antenna of the weak RF signal S _RF received by ANT S / N (signal-to-noise ratio) improved.

The mixer MIX generates, for example, an intermediate frequency signal S _IF which is an intermediate frequency by mixing the amplified high frequency signal S _RF and the local oscillation signal S _LO (frequency f _LO ) generated by the local oscillator _LO. To do.

FIG. 5 shows the filtering characteristics of the bandpass filter. Bandpass filters BPF passes the intermediate frequency signal S _IF, and to remove the other noise is f _BW, the center frequency is f _C band as shown in FIG. 5 (i.e., f _C ± f _BW / 2), and filters or passes the intermediate frequency signal S _IF of the center frequency f _C.

The amplifier AMP amplifies the intermediate frequency signal S _IF subjected to band filtering.

Detection circuit DET, by detecting the amplified intermediate frequency signal S _IF, the antenna ANT is, detects whether it was possible to capture a high-frequency signal S _RF (whether it was possible to receive) The detection signal S _DET indicating whether or not the high frequency signal S _RF has been received is output.

The first AD converter ADC1 converts the amplified detection signal S _DET in an analog format into a digital format.

The demodulating circuit DEM demodulates the amplified intermediate frequency signal _SIF by asynchronous detection (envelope detection), synchronous detection (Costas loop), or the like. The demodulated baseband signal S _BB is
A timepiece circuit (not shown) in the subsequent stage is used for time adjustment.

The control circuit CONT, from the first AD converter ADC1, indicating whether it was possible to capture the high frequency signal S _RF, receives an input of the detection signal S _DET of the digital format. Control circuit C
The ONT also outputs an instruction signal S _CONT for forcibly prescribing the content of a frequency division signal S _DIV (described later) to the frequency divider DIV.

The local oscillator LO, in order to output the local oscillation signal S _LO to mixer MIX, reference oscillator OSC
A phase comparator PD, a low-pass filter LPF, a voltage controlled oscillator VCO, a frequency divider DIV, and a second AD converter ADC2.

The reference oscillator OSC generates a reference local oscillation signal S _OSC .

The phase comparator PD detects a phase difference between the reference local oscillation signal S _OSC and the divided signal S _DIV output from the divider DIV, and outputs a phase difference signal _SPH indicating the phase difference. .

The low-pass filter LPF performs low-pass filtering on the phase difference signal S _PH , that is, the phase difference signal S
By smoothing _PH , a control voltage _VCNT is generated and output.

The voltage controlled oscillator VCO generates a local oscillation signal S _LO having a frequency f _LO defined by the control voltage V _CNT (actually, for example, the frequencies f _VA and f _VB shown in FIG. 2).

The frequency divider DIV is a _divided signal S _DIV obtained by _{dividing the} local oscillation signal _SLO.
Is output.

The second AD converter ADC2 converts the analog-type control voltage _VCNT output from the low-pass filter LPF into a digital format.

<Operation>
The operation of the time information device of the embodiment will be described. FIG. 2 shows the oscillation operation of the local oscillator of the embodiment. In order to facilitate explanation and understanding, the time information device D1 has described that “if the local oscillation signal _SLO having the frequency f _VC is used, the high frequency signal S _RF is substantially converted to the intermediate frequency signal S _IF having the center frequency f _C. Suppose you don't know the fact that you can convert.

Step S1: The control circuit CONT causes the voltage controlled oscillator VCO to change the frequency f _LO of the local oscillation signal S _LO from the frequency f _VA to the frequency f _VE at a stroke, that is, lock-up (stabilization) on the way. The divider DI can be continuously generated without having to stay
An instruction signal S _CONT instructing to that effect is output to V.

Step S2: When the instruction signal S _CONT indicating the above is received from the control circuit CONT,
The frequency divider DIV changes the frequency- _divided signal S _DIV all at once, whereby the phase comparator PD changes the phase difference signal _SPH at once and outputs it to the low-pass filter LPF.

Step S3: In the low-pass filter LPF, by performing a low-filtering the phase difference signal S _PH, as the control voltage V _CNT, as shown in FIG. 2, at once output from the voltage VA to the voltage VE.

Step S4: voltage controlled oscillator VCO, as shown in FIG. 2, the voltage in response to the control voltage V _CNT varying stretch to the voltage VE from the VA, the local oscillation signal S frequency frequency from the frequency f _VA of _LO f Change to _VE at once.

On the other hand, the control voltage V _CNT is also output to the control circuit CONT via the second AD converter ADC2, in other words, the control circuit CONT immediately increases the magnitude of the control voltage V _CNT (
Monitoring (in real time).

Step S5: Local oscillation signal _SLO is changed from frequency f _{VA to} frequency f _{VB to} frequency f _{VC to} frequency f.
_In the process of transition from _{VD to} frequency f _VE , for example, when the frequency is f _VA , the mixer MIX outputs the intermediate frequency signal S _IF of the frequency (f _RF −f _VA ), but the intermediate frequency signal S _IF is As shown in FIG. 5, from being removed by the bandpass filter BPF, ie, not passing through,
The detection circuit DET outputs a detection signal S _DET indicating that the high-frequency signal S _RF has not been received. For example, even when the frequency is f _VB , the intermediate frequency signal S _IF of the frequency (f _RF −f _VB ) is
As shown in FIG. 5, from being removed by the bandpass filters BPF, the detection circuit DET outputs a detection signal S _DET indicating that does not receive the high frequency signal S _RF.

In contrast to the above, at the frequency f _VC , the mixer MIX has a frequency (f _RF −f _VC
) Of the intermediate frequency signal S _IF and the frequency close to the center frequency f _C of the bandpass filter BPF (
f _RF −f _VC ), the intermediate frequency signal S _IF is, as shown in FIGS.
As a result, the detection circuit DET detects that the high-frequency signal S _RF has been received, and the detection signal S _DET indicating the detection is passed through the first AD converter ADC1. To the control circuit CONT.

Step S6: the control circuit CONT when receiving the notification, by detecting the magnitude of the control voltage V _CNT, to know that the control voltage V _CNT is voltage VC.

Step S7: When the control circuit CONT recognizes that the control voltage V _CONT when the high frequency signal S _RF can be captured is the voltage VC, the local oscillation signal S _LO having the frequency f _VC corresponding to the voltage VC. In other words, based on the voltage VC, the frequency of the high-frequency signal _SRF is selected from a plurality of expected (possible) predetermined frequencies, and the selected high-frequency signal is selected. in order to generate a local oscillation signal S _LO having a frequency corresponding to the frequency of the S _RF, the divider DIV, and outputs a control signal S _CNT indicating that.

Step S8: When the frequency divider DIV receives the notification from the control circuit CONT, the frequency f
And outputs a frequency-divided signal S _DIV necessary to generate a local oscillation signal S _LO of _VC, in response to the control voltage V _CNT corresponding to the frequency division signal S _DIV, the voltage controlled oscillator VCO, a frequency f _VC A local oscillation signal _SLO having the following is generated.

<effect>
As described above, the time information apparatus D1 embodiment, the control circuit CONT is, instructs the frequency f _LO of the local oscillation signal S _LO to the frequency divider DIV to increase once the frequency f _VA up to the frequency f _VE, In accordance with the control voltage V _CNT corresponding to the frequency- _divided signal S _DIV output from the frequency divider DIV in response to the instruction, the voltage-controlled oscillator VCO generates a local signal having the frequency f _VE from the local oscillation signal S _LO having the frequency f _VA. The oscillation signal S _LO is generated at once. In the generation process, when the detection circuit DET detects the intermediate frequency signal S _IF that has passed through the bandpass filter BPF, the voltage VC that is the control voltage V _CONT at the time of detection detects the high frequency signal S _RF . recognizes that the voltage needed to capture, as a result, the control circuit CONT is the divider DIV, and instructs to generate a local oscillation signal S _LO frequency f _VC, the voltage controlled oscillator VCO The local oscillation having the frequency f _VC in response to the control voltage V _CNT corresponding to the frequency division signal S _DIV output from the frequency divider DIV and indicating that the local oscillation signal S _LO having the frequency f _VC should be generated. A signal _SLO is generated. Therefore, the time required for conventional as, since there is no need to wait until the generation of the local oscillation signal S _LO is stable until it is possible to know the magnitude of the frequency needed to capture the high frequency signal S _RF Can be shortened as compared with the prior art, and as a result, the power consumption can be reduced as compared with the prior art.

The figure which shows the structure of the time information apparatus of an Example. The figure which shows the oscillation operation | movement of the local oscillator of an Example. The figure which shows the structure of the conventional receiver. The figure which shows the oscillation operation | movement of the conventional local oscillator. The figure which shows the filtering characteristic of a band pass filter.

Explanation of symbols

D1 ... Time information device, MIX ... Mixer, LO ... Local oscillator, BPF ... Band filter, DE
T: Detection circuit, CONT: Control circuit.

Claims (4)

The frequency of the local oscillation signal is generated at a stretch within the range including multiple frequencies that are expected to be able to capture the received signal, and a voltage corresponding to the magnitude of the frequency of the local oscillation signal is output. A local oscillator to
A mixer that converts the frequency of the received signal by mixing the received signal and the local oscillation signal;
A bandpass filter that passes a signal having a predetermined frequency;
A detection circuit for detecting whether or not the signal whose frequency has been converted by the mixer has passed through the bandpass filter in order to determine whether or not the received signal could be captured;
Recognizing that the frequency of the local oscillation signal corresponding to the voltage is necessary to capture the received signal when receiving the fact that the received signal has been captured from the detection circuit, And a control circuit that instructs the local oscillator to continue generating a local oscillation signal having the frequency.   An electronic apparatus comprising the receiving device according to claim 1. The frequency of the local oscillation signal is generated by changing the frequency of the local oscillation signal at a stroke within a frequency range that is expected to be able to capture the reception signal on which the time information is superimposed, and the frequency of the local oscillation signal is A local oscillator that outputs the corresponding voltage;
A mixer that converts the frequency of the received signal by mixing the received signal and the local oscillation signal;
A bandpass filter that passes a signal having a predetermined frequency;
A detection circuit for detecting whether or not the signal whose frequency has been converted by the mixer has passed through the bandpass filter in order to determine whether or not the received signal could be captured;
Recognizing that the frequency of the local oscillation signal corresponding to the voltage is necessary for capturing the received signal when receiving the fact that the received signal has been captured from the detection circuit, A time information device comprising: a control circuit that instructs a local oscillator to continue generating a local oscillation signal having the frequency. Local oscillation that generates the local oscillation signal by changing the frequency of the local oscillation signal within a frequency range that is expected to capture the received signal and outputs a voltage corresponding to the magnitude of the frequency of the local oscillation signal Process,
A mixing step of converting the frequency of the received signal by mixing the received signal and the local oscillation signal;
A band-pass filtering process for passing a signal having a predetermined frequency;
A detection step of detecting whether the signal whose frequency has been converted by the mixing step has passed through the band-pass filtering step in order to determine whether or not the received signal has been captured;
Recognizing that the frequency of the local oscillation signal corresponding to the voltage is necessary to capture the received signal when receiving the fact that the received signal was captured from the detection step, And a control step of instructing to continue generating a local oscillation signal having the frequency in the local oscillation step.

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