JPH0854455A - Gps receiver - Google Patents

Abstract

PURPOSE:To provide a GPS receiver which can prevent waste of power more than required and reduce the power consumption. CONSTITUTION:The GPS receiver comprises a receiving state judging means 12 for judging the propriety of a receiving state to output a voltage control signal in response to judged result to a variable voltage means, and the variable voltage means 13 for varying the voltage of the power source of the means 1 in response to the control signal. When a GPS radio wave is received to measure a receiving position, the means 13 varies, when the means 12 decides that the receiving state is excellent, the power source voltage of receiving binarizing means 1 in a lowering direction in response to the control signal output in response to the decided result. Accordingly, the voltage of the binarizing means is lowered when the receiving state is excellent, thereby reducing the power consumption of the receiver.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a GPS receiver for receiving GPS radio waves and positioning the reception position.

[0002]

2. Description of the Related Art FIG. 4 is a block diagram of a conventional GPS receiver. Reference numeral 14 as a component is reception binarization means for receiving GPS radio waves and converting them into IF signals. 15 is a navigation data detection device, which has four channels CH1 and CH
2, CH3, CH4, and channel CH1 is PN
A code generating means 5; a demodulating means 3 for despreading a signal based on the PN code output from the PN code generating means 5;
It has a low-pass filter (LPF) 4, a tuning means 6, and a navigation data detecting means 7. In addition, channel C
The configuration of H2, CH3, and CH4 is the same as that of channel CH1.

Reference numeral 17 is a PN of each channel CH1 to CH4.
Setting of code generating means 5 and each channel CH1 to CH
4 is a main computer for analyzing navigation data from 4 and positioning calculation, 10 is a reference clock means,
Reference numeral 18 is a clock means for making a plurality of clocks. A bus 16 connects the navigation data detector 15, the main computer 17, and the clock means 18 to each other.

The operation of the GPS receiving device including the above-described components will be described below with reference to the drawings.

The reception binarizing means 14 receives GPS radio waves and converts them into IF signals. Main computer 17 is PN
The code and timing of the code generating means 5 are set.
The demodulation means 3 despreads the IF signal based on the PN code generated by the PN code generation means 5. The despread and demodulated signal is integrated by a low pass filter (LPF) 4, and navigation data detecting means 7 extracts navigation data.

The main computer 17 repeats the analysis of the navigation data of CH1 and the setting of the PN code generation means 5 until the navigation data can be taken out from the channel CH1 of the navigation data detection device 15. Main computer 17
Performs the same as for channel CH1 for each channel from channel CH2 to channel CH4 of navigation data detection device 15. When the navigation data can be extracted from all the channels CH1 to CH4 of the navigation data detection device 15, the main computer 17 causes the satellite time data included in the navigation data and each channel CH1 to CH1.
Positioning calculation is performed using the timing deviation of the PN code generation means 5 of CH4.

FIG. 5 is a diagram showing the noise characteristic with respect to the power supply voltage of the reception binarization means 14 in the conventional GPS receiver, the vertical axis is the NF value or the CN value, and the horizontal axis is the reception binarization means 14. Power supply voltage. In FIG. 5, 19 is the NF value of the reception binarization means 14, 20 is the CN value of the IF signal when the reception environment is good, and 21 is the CN value of the IF signal when the reception environment is the worst. Yes, 22 is the sensitivity of the navigation data detection device 15. According to the characteristics shown in FIG. 5, when the power supply voltage becomes smaller, N of the reception binarization means 14 becomes smaller.
Since the F value increases, the CN value of the IF signal deteriorates.

[0008]

However, in the conventional GPS receiving apparatus as described above, even if the receiving environment becomes the worst and the receiving state deteriorates, the NF of the receiving binarizing means.
In order to prevent deterioration of characteristics, it is not designed with a low power supply voltage. Therefore, even when the reception environment is improved and the reception state is improved, the power supply voltage cannot be lowered and power is wasted more than necessary.

The present invention solves the above problems and can reduce the power consumption when the reception environment is improved and the reception state is improved, thereby preventing unnecessary power consumption. It is an object of the present invention to provide a GPS receiving device capable of achieving low power consumption.

[0010]

In order to achieve the above object, the GPS receiving apparatus of the present invention converts the received GPS radio wave into an IF signal by the reception binarizing means, and based on this IF signal, the demodulating means performs the above-mentioned conversion. In a GPS receiving device that demodulates GPS radio wave information to measure the reception position, it is determined whether or not the reception state is good, and a reception state determination unit that outputs a voltage control signal according to the determination result, and the reception state determination unit. A variable voltage means for varying the power supply voltage of the reception binarization means in accordance with the voltage control signal output from Then, the power supply voltage of the reception binarization means is changed in the direction of decreasing.

Further, the variable voltage means is configured to vary the power supply voltage of only the first-stage amplifier immediately below the antenna in the reception binarization means.

[0012]

According to this configuration, when the reception state determining means determines that the reception state is good when receiving the GPS radio wave and positioning the reception position based on the GPS radio wave, the reception result is determined according to the determination result. The variable voltage means changes the power supply voltage of the reception binarization means in the direction of decreasing it in accordance with the voltage control signal output as described above. Therefore, it is possible to reduce the power consumption of the GPS receiver when the reception environment is good.

Further, since the NF value of the circuit largely contributes to the preceding stage of the amplifier, by controlling only the first-stage amplifier immediately below the antenna in the reception binarizing means, it is possible to control the entire reception binarizing means. The circuit design becomes easy.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A GPS receiver according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of the GPS receiver of this embodiment. In FIG. 1, 1 is a GPS as a component.
It is a reception binarization unit that receives a radio wave and converts it into an IF signal. Reference numeral 2 denotes a navigation data detection device, which has four channels CH1 for receiving signals from four satellites at the same time,
It is equipped with CH2, CH3, and CH4.

The channel CH1 has a PN code generating means 5
And a demodulation means 3 for despreading the IF signal based on the PN code generated by the PN code generation means 5, a low pass filter (LPF) 4, a tuning means 6, and a navigation data detection means 7. There is. Other channels CH2, CH3
Also, the configurations of CH4 and CH4 are the same as those of the channel CH1.

Reference numeral 9 is a PN of each channel CH1 to CH4.
It is a main computer for setting the code generating means 5, analyzing navigation data from each of the channels CH1 to CH4, and performing positioning calculation. In addition to these processes, the main computer 9 performs positioning calculation and then outputs the channel number used for the positioning calculation (hereinafter, abbreviated as usage number) to the reception state determination means 12. Reference numeral 10 is a reference clock means, and 11 is a clock means for producing a plurality of clocks based on the signal from the reference clock means 10.

Reference numeral 12 inputs the integrated output of the low-pass filter (LPF) 4 of each channel of the navigation data detection device 2, compares the integrated value of this integrated output with a predetermined determination level at regular intervals, and indicates the reception state. It is a reception state determination means that determines pass / fail and outputs a voltage control signal according to the determination result.

Reference numeral 13 supplies power to the reception binarization means 1 and varies the power supply voltage supplied to the reception binarization means 1 by a constant value in accordance with the voltage control signal output from the reception state determination means 12. It is a variable voltage means. Here, the reception state determination means 12 determines that the reception state is good when all the integrated values of the usage numbers of the navigation data detection device 2 exceed a predetermined determination level, and the reception state determination means 12 instructs the variable voltage means 13 to operate. Then, a voltage control signal for lowering the power supply voltage of the reception binarization means 1 by a constant value is output.

A bus 8 interconnects the navigation data detection device 2, the main computer (positioning control calculation means) 9, the clock means 11 and the reception state determination means 12.

The operation of the GPS receiving apparatus including the above-described components will be described below.

When the power is turned on, the variable voltage means 13 supplies the maximum power supply voltage to the reception binarization means 1. The reception binarizing means 1 receives GPS radio waves and outputs an IF signal. Until the first positioning is completed, the main computer 9 does not output the usage number to the reception state determination means 12, and the power supply voltage of the reception binarization means 1 remains the maximum voltage. When the main computer 9 performs positioning calculation based on the navigation data from the navigation data detecting means 7 of each of the channels CH1 to CH4, the main computer 9 outputs the use number to the reception state determining means 12.

The reception state judging means 12 compares the integrated value of the low pass filter (LPF) 4 of each channel CH1 to CH4 of the navigation data detecting device 2 with a predetermined judgment level,
When all the integrated values of the low pass filter (LPF) of the use number exceed a predetermined determination level, a voltage control signal is output to the variable voltage means 13.

When the voltage control signal is input, the variable voltage means 13 lowers the power supply voltage of the reception binarization means 1 by a constant voltage. When the power supply voltage decreases, the gain and noise level of the reception binarization means 1 decrease, and the integrated value of the low pass filter (LPF) 4 decreases.

Since the receiving state judging means 12 compares the integrated value of the low-pass filter (LPF) 4 with the judgment level at regular intervals, until all the integrated values of the use number are below the judgment level. The variable voltage means 13 continuously lowers the power supply voltage of the reception binarization means 1.

In the above, the judgment level is set higher than the lower limit level at which the navigation data is correctly detected. However, when the integrated value of all channels falls below the lower limit level by one voltage drop, the reception state judging means is set. If the 12 is configured to output a voltage control signal that raises the voltage of the reception binarization means 1 to the variable voltage means 13, the navigation data can be reliably detected.

By the above operation, it is possible to reduce the power consumption when the reception environment is improved and the reception state is improved, it is possible to prevent unnecessary power consumption, and to reduce the power consumption. be able to.

In the above embodiment, the reception state judging means 12
Judges that the reception state is good when all the integrated values of the usage numbers of the navigation data detection device 2 exceed a predetermined judgment level, and the variable voltage means 13 receives the received binarization means 1 Is configured to output a voltage control signal for lowering the power supply voltage of the device by a fixed value, but the reception state is good when the CN value of the output of the reception binarization means 1 exceeds a predetermined determination level. It is also possible to configure so as to output to the variable voltage means 13 a voltage control signal for lowering the power supply voltage of the reception binarization means 1 by a constant value.
The same effect can be obtained.

As one embodiment, a configuration in which the voltage of the first stage amplifier of the reception binarization means 1 is lowered when the reception state is good will be described in detail below with reference to the drawings.

FIG. 2 shows a block diagram of the reception binarizing means 1 of the GPS receiving apparatus of this embodiment. In the reception binarization means 1, 101 is a GPS reception antenna as a component,
Reference numeral 102 denotes a first-stage amplifier supplied with the power supply voltage from the variable voltage means 13, 103 denotes a second-stage amplifier, and 104 denotes mixer means for converting the GPS frequency into an IF frequency by using the input reference clock. 105 is mixer means 104
It is a binarizing means for converting the signal from the IF signal into an IF signal. In addition,
Reference numeral 13 is a variable voltage means, 10 is a reference clock means, and 2 is a navigation data detecting means.

In the reception binarizing means 1 including the above-mentioned components, the GP received by the GPS receiving antenna 101
The S signal is the first stage amplifier 102 and the second stage amplifier 103.
Is amplified through the frequency converter, frequency converted by the mixer means 104, and converted into an IF signal by the binarization means 105. When the power supply voltage supplied from the variable voltage means 13 decreases, the current consumption of the first-stage amplifier 101 inside the reception binarization means 1 decreases.

FIG. 3 is an explanatory diagram of signals and noise of the reception binarizing means 1 of the GPS receiving apparatus according to one embodiment of the present invention.
106 is noise and signals when the voltage of the variable voltage power supply 13 is high, 107 is noise and signals when the voltage of the variable voltage power supply 13 is low, 108 on the horizontal axis is the output of the GPS receiving antenna 101, and 109 is The output of the first stage amplifier 102, 110 is the output of the second stage amplifier 103, 111 is the output of the mixer means 104, and 112 is the output of the binarization means 105. Further, on the vertical axis, 113 is a GPS signal, 114 is antenna noise, and 115 is the first stage amplifier 102.
Is generated by the second stage amplifier 103, 117 is generated by the mixer means 104, and 118 is generated by the binarization means 105.

As described above, in this embodiment, the voltage of the first-stage amplifier 102 is lowered when the reception state is good, and the noise performance is deteriorated in the circuits other than the first-stage amplifier 102 of the reception binarizing means 1. Narrows down the current in advance,
By compensating for the deterioration of the noise performance with the first-stage amplifier 102, it is possible to deal with a case where the reception state is bad. With such a configuration, lower power consumption of the GPS can be achieved with a design easier than changing the entire reception binarization means.

[0034]

As is apparent from the above description of the embodiments, according to the present invention, when the GPS radio wave is received and the reception position is determined based on the GPS radio wave, the reception state determining means determines the reception state. When it is determined that the variable voltage means is good, the variable voltage means can change the power supply voltage of the reception binarizing means in the direction of decreasing it according to the voltage control signal output according to the determination result.

Therefore, it is possible to reduce the power consumption when the reception environment is improved and the reception state is improved, it is possible to prevent the consumption of power more than necessary, and it is possible to reduce the power consumption. .

If the power supply voltage of only the first-stage amplifier of the reception binarization means is changed so as to be decreased, and the circuits other than the first-stage amplifier are configured so that the current is narrowed in advance, the entire reception binarization means can be obtained. It is possible to reduce the power consumption of GPS with a design easier than changing the.

[Brief description of drawings]

FIG. 1 is a block diagram of a GPS receiver according to an embodiment of the present invention.

FIG. 2 is a block diagram of reception binarizing means of the GPS receiving apparatus according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram of signals and noise of a reception binarizing unit of the GPS receiving apparatus according to the embodiment of the present invention.

FIG. 4 is a block diagram of a conventional GPS receiver.

FIG. 5 is a diagram showing a noise characteristic with respect to a voltage of the reception binarizing means of the conventional example.

[Explanation of symbols]

 1 reception binarization means 2 navigation data detection device 3 demodulation means 7 navigation data detection means 9 main computer 10 reference clock means 11 clock means 12 reception state determination means 13 variable voltage means

Claims (4)

[Claims] 1. A GPS receiver for positioning a reception position by converting a received GPS radio wave into an IF signal by a reception binarizing means and demodulating means for demodulating the GPS radio wave information based on the IF signal. The reception state determination means for determining the quality of the reception state and outputting a voltage control signal according to the determination result, and the reception binarization means for the voltage control signal output from the reception state determination means A variable voltage means for varying the power supply voltage, wherein the variable voltage means is adapted to vary the power supply voltage of the reception binarization means with respect to the reception status determination of the reception status determination means. A GPS receiving device characterized by being configured. 2. The GPS receiving apparatus according to claim 1, wherein the receiving state determining means is configured to determine whether the receiving state is good or bad based on the CN value of the output of the receiving binarizing means. 3. The GPS receiving apparatus according to claim 1, wherein the reception state determining means is configured to determine whether the reception state is good or bad based on the integrated value of the output of the demodulating means. 4. The GPS according to claim 1, wherein the variable voltage means is configured to vary the power supply voltage of only the first-stage amplifier immediately below the antenna in the reception binarization means.
Receiver.