JP2001215268A - Receiver for global positioning system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a receiver for a global positioning system capable of reporting an accurate present position while reducing electricity consumption. SOLUTION: This GPS(global positioning system) receiver 11 used for detecting the position of a movable body is provided with a GPS receiving circuit 3 and a GPS demodulating circuit 4, for intermittently receiving and demodulating a satellite signal transmitted from a GPS satellite, and an intermittent-reception control circuit 12 for controlling intermittent reception intervals for the intermittent reception at the circuits 3, 4 according to the moving speed of the movable body. This enables the intermittent reception and demodulation to be performed with optimal intermittent reception intervals according to the speed of the movable body. A more accurate present position can be reported to a user while keeping unchanged a positioning error made during the intermittent reception without increasing electricity consumption.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a receiver for a global positioning system, for example, a GP for measuring the position of a moving object.
It is suitable for application to an S (Global Positioning System) receiver.

[0002]

2. Description of the Related Art Conventionally, in a GPS, satellite signals respectively transmitted from a plurality of GPS satellites orbiting the earth are received by a GPS receiver, and the received satellite signals are analyzed to obtain the GPS receiver. And each GP
Obtain the distances from the S satellites respectively, and use these to determine the GPS
The current position of a moving object equipped with a receiving device is calculated.

[0003] A satellite signal transmitted from this GPS satellite is a PN consisting of a different type of code sequence for each GPS satellite.
(Pseudo noise) code, that is, a signal that is spread spectrum by a pseudo noise code.

[0004] Accordingly, the GPS receiving apparatus can use a plurality of types of GPs.
A local PN code corresponding to each of the S satellites can be generated. The phase of the generated local PN code is adjusted to the phase of the PN code of the satellite signal to obtain synchronization, and tracking is performed on the satellite signal. , The navigation message (orbit information for positioning calculation, etc.) from each GPS satellite is demodulated by performing spectrum despreading processing, and the current position is calculated based on the navigation message. It has been made like that.

[0005] In practice, as shown in FIG. 4, the GPS receiver 1 sends out a GPS reception signal S 1 received from each GPS satellite via a GPS antenna 2 and a GPS receiver 3 to a GPS demodulator 4.

The GPS demodulation circuit 4 includes an intermittent reception control circuit 5
A demodulation process is performed by receiving the GPS reception signal S1 from each GPS satellite at the intermittent reception timing based on the intermittent reception control signal S3 supplied from the GPS receiver, acquiring the synchronization using the local PN code, and performing the spectrum despreading process. ,
The resulting reception data S2 for each GPS satellite is sent to the positioning circuit 6, respectively.

The positioning circuit 6 performs GP based on the reception data S2 for each GPS satellite obtained at each intermittent reception timing.
The distance between the S receiving apparatus 1 and each GPS satellite is obtained, and the current position of the moving object is measured based on the distance.

[0008]

In the GPS receiver 1 having such a configuration, the GPS reception signal S1 is intermittently received only at the intermittent reception timing based on the intermittent reception control signal S3 in order to reduce power consumption as much as possible. The demodulated data is then demodulated, and the positioning position obtained as a result is superimposed and displayed on a map on a display unit by a predetermined mark or the like.

[0009] That is, the GPS receiver 1 is, for example, as shown in FIG.
As shown in (2), as the reception interval for intermittently receiving the GPS reception signal S1 is set longer, the standby time becomes longer and the power consumption can be reduced.

[0010] However, as shown in FIG. 6, the GPS receiver 1 can reduce power consumption when the reception interval of the GPS reception signal S1 becomes longer while the moving body is moving at a constant speed. There is a problem that an error between the current position of the moving body that is moving and the measured position increases in proportion to the length, and it is not possible to notify the user of an accurate current position.

The present invention has been made in view of the above points, and it is an object of the present invention to propose a receiver for a global positioning system which can notify a more accurate current position while reducing power consumption.

[0012]

According to the present invention, there is provided a global positioning system receiving apparatus for detecting the position of a moving object which intermittently transmits a satellite signal transmitted from a satellite of the global positioning system. Optimum intermittent reception according to the moving speed of the mobile unit is provided by providing a receiving unit that performs reception and demodulation processing and a control unit that controls an intermittent reception interval of the intermittent reception in the receiving unit according to the moving speed of the mobile unit Since the satellite signals can be intermittently received and demodulated at intervals, the positioning error during intermittent reception can be maintained at a constant accuracy, and the user can receive a more accurate current position without increasing power consumption. Can be notified.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

(1) First Embodiment In FIG. 1 in which parts corresponding to those in FIG. 4 are assigned the same reference numerals, reference numeral 11 denotes a whole as a receiving device of the global positioning system in the first embodiment. 1 shows a GPS receiver, in which the GPS receiver 11 is mounted as a mobile object on, for example, an automobile, and each circuit operates based on power supplied from a battery (not shown).

In this case, the GPS receiver 11 first
Each GPS via the PS antenna 2 and the GPS receiving circuit 3
The GPS reception signal S1 received from the satellite is
The signal is sent to the demodulation circuit 4.

The GPS demodulation circuit 4 includes an intermittent reception control circuit 1
2 from the GPS satellites at the intermittent reception timing based on the intermittent reception control signal S12 supplied from
After receiving the signals 1 and 2, respectively, by using the local PN code to obtain synchronization, demodulation processing is performed by performing spectrum despreading processing, and the resulting reception data S2 for each GPS satellite is sent to the positioning circuit 6.

The positioning circuit 6 performs GP based on the reception data S2 for each GPS satellite obtained at each intermittent reception timing.
The distance between the S receiving device 1 and each GPS satellite is obtained, and based on these, the position data S6 of the positioning result (hereinafter, referred to as the positioning position) is calculated and transmitted to the moving speed detection circuit 13. I do.

At the same time, the positioning circuit 6 sends the position data S6 to a display unit 14 composed of a liquid crystal display. Display 1
No. 4 displays a predetermined mark at a point on the map corresponding to the position data S6, thereby notifying the user of the measured position as the current position.

The moving speed detecting circuit 13 detects a moving object based on a distance interval between two points corresponding to two position data S6 sequentially supplied from the positioning circuit 6 at each intermittent reception timing and a time interval of the intermittent reception timing. And the resulting moving speed information S13 is sent to the intermittent reception control circuit 12.

The intermittent reception control circuit 12 has a CPU (Central
And a GP based on the moving speed information S13 of the moving object supplied from the moving speed detection circuit 13.
The intermittent reception interval in the S demodulation circuit 4 is controlled.

That is, the intermittent reception control circuit 12 shortens the intermittent reception interval in the GPS demodulation circuit 4 as the moving speed of the moving body increases based on the moving speed information S13 as shown in FIG. The intermittent receiving interval in the GPS demodulation circuit 4 is controlled to be longer as the moving speed of the GPS receiver becomes lower.

In this case, the intermittent reception control circuit 12 stores an intermittent reception control table (not shown) in an internal memory, and based on the intermittent reception control table, sets the intermittent reception interval in accordance with the moving speed of the mobile unit. Control.

Incidentally, the relationship between the moving speed and the intermittent reception interval depends on the accuracy of keeping the error between the current position and the measured position constant, and it is necessary to reduce the error between the current position and the measured position. May be controlled based on an intermittent reception control table that makes the intermittent reception interval shorter regardless of the moving speed.

In the above configuration, the GPS receiver 11
Is the moving speed information S supplied from the moving speed detecting circuit 13.
13, the moving speed of the moving body is, for example, 100 [K / hour].
m], the intermittent reception interval in the GPS demodulation circuit 4 is shortened in accordance with the intermittent reception control table, and when the moving speed of the mobile body is low at a walking speed of, for example, about 5 [km] per hour, the intermittent reception control table is used. Is controlled so as to lengthen the intermittent reception interval in the GPS demodulation circuit 4 in accordance with

As described above, the GPS receiving apparatus 11 controls the GPS reception signal S1 so as to intermittently receive and demodulate the GPS reception signal S1 at the optimum intermittent reception interval in accordance with the moving speed of the moving body, thereby changing the moving speed. Even when the GPS receiving signal S1 is intermittently received while being mounted on a moving mobile body, positioning can be performed while maintaining the error between the current position of the mobile body and the positioning position within a certain range.

Further, the GPS receiver 11 wastes power consumption while maintaining a constant error between the current position and the positioning position of the moving object by increasing the intermittent reception interval in the GPS demodulation circuit 4 when moving at low speed. Can be prevented, and the life of the battery can be further extended.

According to the above configuration, the GPS receiver 11
Optimally controls the intermittent reception interval of the GPS reception signal S1 according to the moving speed of the moving object, so that the intermittent reception is always performed within a certain error range even when the intermittent reception is performed when the moving speed of the moving object is variable. The user can be notified of the current position of the moving object.

(2) Second Embodiment In FIG. 3, in which parts corresponding to those in FIG. 1 are assigned the same reference numerals, reference numeral 21 denotes a GPS as a whole in the second embodiment.
This figure shows a receiving device, which is mounted on a mobile phone, for example, as a mobile body, and has a configuration in which a CDMA transmitting / receiving unit 20 is newly combined.

In this case, the GPS receiver 21
In the transmission / reception unit 20, a CDMA antenna 22 and a CDMA antenna from a base station (not shown) of the CDMA cellular system
CDMA reception signal S2 received via transmission / reception circuit 23
3 to the CDMA demodulation circuit 24.

The CDMA demodulation circuit 24 performs demodulation processing after acquiring synchronization with the CDMA reception signal S23 based on the CDMA demodulation control signal S26 supplied from the CDMA control circuit 25, and receives the demodulated reception data S2.
4 is sent to the CDMA control circuit 25.

On the other hand, the CDMA control circuit 25 sends out transmission data S27 such as data to be transmitted and voice to the CDMA modulation circuit 26,
A CDMA modulation control signal S28 for controlling the spread spectrum processing in S6 is sent to the CDMA modulation circuit 26.

The CDMA modulation circuit 26 modulates the transmission data S27 according to the CDMA modulation control signal S28,
This is a CDMA transmission signal S subjected to spread spectrum processing.
29 is transmitted from the CDMA antenna 22 to the base station of the CDMA cellular system via the CDMA transmitting / receiving circuit 23.

By the way, the CDMA control circuit 25 controls the CDM
By analyzing the received data S24 supplied from the A demodulation circuit 24, the current position of the mobile phone measured by the base station of the CDMA cellular system is recognized, and this is used as the CDMA position data S25 to detect the moving speed of the mobile phone 1.
Supply 3

The moving speed detecting circuit 13 receives the CDMA signal supplied from the CDMA control circuit 25 of the CDMA transmitting / receiving section 20.
The moving speed of the mobile phone is calculated based on the position data S25, and the resulting moving speed information S13 is sent to the intermittent reception control circuit 12.

In this case, the intermittent reception control circuit 12
As shown in (1), as the moving speed of the moving object increases based on the moving speed information S13, the intermittent reception interval in the GPS demodulation circuit 4 decreases, and as the moving speed of the moving object decreases, the GPS demodulation decreases. Control is performed so that the intermittent reception interval in the circuit 4 is lengthened.

The position data S6 measured by the positioning circuit 6 is transferred to the moving speed information S
13 is used only for displaying a point corresponding to the position data S6 on the map of the display unit 14, instead of being used for calculating the position data S13.

In the above configuration, the GPS receiver 21
Calculates the moving speed of the mobile phone based on the CDMA position data S25 supplied from the CDMA transmitting / receiving unit 20, and controls the intermittent reception interval in the GPS demodulation circuit 4 according to the moving speed, thereby changing the moving speed. Even if the GPS reception signal S1 is intermittently received while the mobile phone is mounted on a mobile phone that moves, positioning can be performed while maintaining the error between the current position of the mobile phone and the positioning position within a certain range.

According to the above configuration, the GPS receiver 21
Optimally controls the intermittent reception interval of the GPS reception signal S1 in accordance with the moving speed of the mobile phone, so that the intermittent reception is always performed within a certain error range even when the intermittent reception is performed when the moving speed of the mobile phone varies. The user can be notified of the current location of the mobile phone.

(3) Other Embodiments In the above-described first and second embodiments, the moving speed information S13 of the moving object is calculated by the moving speed detecting circuit 13, and this is calculated by the intermittent reception control circuit 12. Has been described, the present invention is not limited to this. For example, the moving speed information S calculated based on the vehicle speed pulse of the automobile
13 may be sent to the intermittent reception control circuit 12.

In the above-described first and second embodiments, the case where the moving speed information S13 of the moving body is calculated by the moving speed detection circuit 13 and is transmitted to the intermittent reception control circuit 12 is described. As described above, the present invention is not limited to this. For example, a frequency error detection circuit (not shown) is provided inside the GPS demodulation circuit 4, and the moving speed information S13 is obtained based on the Doppler frequency obtained by the frequency error detection circuit. It may be calculated and sent to the intermittent reception control circuit 12.

In the first and second embodiments, the GPS reception signal S1 received by the GPS antenna 2 and the GPS reception circuit 3 is intermittently output by the GPS demodulation circuit 4 based on the control of the intermittent reception control circuit 12. Although the case where reception and demodulation processing are performed has been described, the present invention is not limited to this, and the GPS is controlled based on the control of the intermittent reception control circuit 12.
The receiving circuit 3 may intermittently receive the GPS reception signal S1.

Further, in the first and second embodiments, the intermittent reception control circuit 12 controls the intermittent reception interval according to the moving speed based on the intermittent reception control table stored in the internal memory. Although the case has been described, the present invention is not limited to this, and the intermittent reception interval may be flexibly changed according to the moving speed.

Further, in the first and second embodiments described above, the GP as the receiving device of the global positioning system
S receiving apparatuses 11 and 21 intermittently receive and demodulate satellite signals transmitted from GPS satellites by GPS antenna 2, GPS receiving circuit 3, and GPS demodulating circuit 4 as receiving means, and perform intermittent reception control as control means. The case where the intermittent reception interval is controlled by the circuit 12 in accordance with the moving speed of the moving object has been described, but the present invention is not limited to this, and the intermittent reception interval is controlled by other various receiving means and control means. You may do it.

[0044]

As described above, according to the present invention, in a receiver for a global positioning system for detecting the position of a moving object, a satellite signal transmitted from a satellite of the global positioning system is intermittently received and demodulated. Receiving means, and control means for controlling the intermittent reception interval of the intermittent reception in the receiving means in accordance with the moving speed of the moving body, so that the satellite signal can be transmitted at the optimum intermittent receiving interval in accordance with the moving speed of the moving body. Since it is possible to perform intermittent reception and demodulation processing, it is necessary to notify the user of a more accurate current position without increasing power consumption while maintaining a positioning error at the time of performing intermittent reception with a certain accuracy. Can be.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a GPS receiving device according to a first embodiment.

FIG. 2 is a characteristic curve diagram showing a relationship between a moving speed and a reception interval.

FIG. 3 is a block diagram illustrating a configuration of a GPS receiving device according to a second embodiment.

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

FIG. 5 is a characteristic curve diagram showing a relationship between a conventional reception interval and power consumption.

FIG. 6 is a characteristic curve diagram showing a relationship between a reception interval and a positioning error when moving at a constant speed in the related art.

[Explanation of symbols]

1, 11, 21 ... GPS receiving device, 2, 12, ... GP
S antenna, 3 ... GPS reception circuit, 4 ... GPS demodulation circuit, 5, 12 ... Intermittent reception control circuit, 6 ... Positioning circuit, 13 ... Moving speed detection circuit, 20 ... CDMA transmission / reception section, 23 ... ... CDMA transmission / reception circuit, 24 ... CDMA
Demodulation circuit, 25 CDMA control circuit, 26 CDM
A modulation circuit.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04B 7/26 X9A001 (72) Inventor Koichiro Teranishi 6-7-35 Kita Shinagawa, Shinagawa-ku, Tokyo Sony Stock In-house F term (reference) 2F029 AA02 AB07 AC02 AC12 5G065 AA01 EA02 FA05 GA07 JA07 KA00 PA01 5H180 AA01 BB05 FF05 FF22 FF33 5J062 BB01 BB02 BB03 CC07 DD14 HH05 5K067 BB32 CC22 EE02HJJ56 9J78A 001

Claims (3)

[Claims] 1. A receiving device of a global positioning system for detecting a position of a moving object, comprising: receiving means for intermittently receiving and demodulating a satellite signal transmitted from a satellite of the global positioning system; Control means for controlling an intermittent reception interval of said intermittent reception in said reception means in accordance with a moving speed. 2. The global positioning system according to claim 1, wherein said receiving device comprises speed detecting means for detecting said moving speed of said moving body based on a demodulation result by said receiving means. Receiving device. 3. The receiving device according to claim 1, further comprising: position information receiving means for receiving position information indicating the position of the mobile unit from a base station of a predetermined communication system; and receiving the position information based on the position information received by the position information receiving means. The receiving device of the global positioning system according to claim 1, further comprising speed detecting means for detecting the moving speed of the moving body.