JP2003185731A - Gps terminal of network support type - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a size, a weight and a price compared with the prior art, while securing sensitivity and TTFF of the same degree same to those of a conventional terminal or more. <P>SOLUTION: A host CPU 34A is brought into a sleep condition during execution of a snap shot in a GPS module 18. Unnecessary radiation by the host CPU 34A does not deteriorate an S/N ratio of a received signal by the GPS module 18. Electromagnetic shielding as to the host CPU 34A is not required thereby. When transmission by a PDC-P module 20 is stopped during the execution of the snap shot in the GPS module 18, a TXACTV for indicating that the PDC-P module 20 is under execution of the transmission is not required to be supplied to a DSP 32 inside the GPS module 18. A member corresponding to the host CPU 34A is allowed to be incorporated into the PDC-P module 20. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a network-assisted GPS terminal that measures pseudoranges of GPS satellites designated by a location server and sends the results to the location server.

[0002]

2. Description of the Related Art In recent years, portable wireless communication terminals such as mobile phones and PHSs that can be easily used have become widespread. On the other hand, as a compact and lightweight positioning terminal with high accuracy, GP
S (Global Positioning System) receivers are also widely used. Against this background, there is a demand for a location information service using a mobile phone network or the like, especially a service with a fulfilling content.

FIG. 3 shows an example of an implementation environment for this type of service. In the system shown in this figure, the terminal 10
And the server 12 are connected to each other via the network 14. The terminal 10 is a terminal that has both a function as a GPS receiver and a function as a mobile phone, for example, and sends information obtained by receiving signals from GPS satellites 16 to the server 12 via the network 14. To send. The network 14 is a network including, for example, a mobile phone network and a wide area network, and the terminal 10 wirelessly connects to the network 14 by its mobile phone function.

The server 12 collects information from the terminal 10 via the network 14 and provides a predetermined service based on the collected information. For example, in response to a request from the outside, the terminal 10 and, by extension, the service of searching the position of the owner or tracking the position are provided. Therefore, this type of server is called a location information server or location server (LS). Note that in the present application, the information regarding the position of the terminal 10 or the information obtained by processing the information is LS1.
Services provided by 2 are collectively referred to as location information services.

[0007] The position information service can be roughly classified into a terminal 10 that completes a series of positioning procedures from reception of signals from GPS satellites 16, measurement of pseudoranges, and derivation of the current position. There are an implementation mode and an implementation mode in which a part of the series of positioning procedures is performed by the LS 12. The latter, that is, a network-supported implementation, is based on satellite designation by the LS 12, digital signal analysis at the terminal 10 and transmission of the pseudorange obtained as a result, for example, WAG (Wireless) proposed by SnapTrack. Assisted GPS).

In a network-assisted GPS represented by WAG or the like, the LS 12 holds information regarding all GPS satellites 16, for example, information indicating the orbits of each GPS satellite 16. LS1 for location information service
2 identifies the GPS satellite 16 in the position where the terminal 10 can see, that is, the visible satellite, based on the general position of the terminal 10 and the held information. The LS12 excludes, from the visible satellites, those that are unusable / unsuitable in view of their health condition or geometrical positional relationship, based on the positioning calculation by the terminal 1
Identify more visible satellites than necessary to determine the zero position.

[0007] The LS 12 issues a positioning instruction having the content of designating the specified visible satellites as targets of pseudorange measurement. The positioning instruction issued from the LS 12 is received by the terminal 10 via the network 14. Terminal 10
Pseudo distance measurement is performed on the GPS satellite 16 designated by the positioning instruction, and the result is transmitted to the LS 12 via the network 14. LS12 is the terminal 10
Pseudo-range received from each GPS
Based on the information about the satellite 16, the position of the terminal 10 is calculated, and the result is provided to the person who requests the position search.

Regarding the outline of WAG, for example, 2
The Japan Society for Navigation Research, GPS Study Group, Chapter 6, “Mobile Phone Networks and GPS”, November 6.2, “6.2 Basic Technologies for Network-Assisted GPS” (Hiya Taniuchi),
See “6.3 LSI Chip Set for Network-Assisted GPS” (Hisao Ishizuka). In addition, the rough position of the terminal 10 among the information used for specifying / selecting the visible satellite is notified from the terminal 10 to the LS 12 via the network 14, or the position of the terminal 10 is measured in a relatively recent (for example, last) measurement. You can get from the results. Furthermore, W
In the AG, the LS12 indicates the Doppler frequency of the designated GPS satellite 16, that is, the information indicating the Doppler shift appearing in the signal transmitted from the GPS satellite 16.
It is included in the positioning instruction from the terminal 10 to assist the sensitivity improvement in the terminal 10.

FIG. 4 shows a conventional network-assisted GP.
1 shows a typical configuration of a terminal 10 being developed for S. This figure shows PDC-P (Personal Digital Cellula)
This is an example of connecting the terminal 10 to the network 14 by wireless connection to the r-Packet) network. Since it is possible to use other types of mobile telephone networks or wireless communication networks, in that case, "PDC-P" in the figure should be read as appropriate. In addition, the first of the above-mentioned GPS study materials
On page 64, a similar figure is shown as FIG. 6.3.5, so refer to it as appropriate. Further, FIG. 5 shows an operation flow of the terminal 10 shown in FIG. 4 and a communication flow between the terminal 10 and the LS 12. This figure shows the procedure shown in Fig. 6.3.8 on page 166 in the above-mentioned GPS study material.
It is expressed in a more general format with details omitted.

The terminal 10 shown in FIG. 4 accommodates a GPS module 18, a PDC-P module 20, a control board 22, a battery (not shown), etc. in a common and single housing,
Further, it has a structure in which a GPS antenna 24 and a PDC antenna 26 are provided on the surface or inside of the housing. Among the modules that configure the terminal 10, the GPS module 18 receives a radio signal belonging to a frequency band used in GPS by the GPS antenna 24 and measures a pseudo range for the GPS satellite 16 designated by the positioning instruction. It is a module that performs down conversion 28, snapshot RAM 30, DSP (Digital Signal Processo).
r) 32 etc. Although not shown for simplification,
It also has an A / D converter, a TCXO, and the like. Of the terms used here, snapshot is SnapT.
is a trademark of rac or SnapTrack Japan.

The PDC-P module 20 is a wireless module for wireless connection to the network 14 (in this case, connection by PDC-P). Although not shown for simplification, a transmission / reception unit for transmitting / receiving / modulating / demodulating a radio signal using the PDC antenna 26, a control unit for controlling the operation of the transmission / reception unit, and the like are provided. And the control board 2
2 has a configuration in which a substrate on which a host CPU 34, a RAM 36, a ROM 38, etc. are mounted is housed in a shield case. The host CPU 34 is a processor that performs local control of the GPS module 18 and mediation of information exchange between the PDC-P module 20 and the GPS module 18, and the RAM 36 and the ROM 38 are the host CPU 3
4 provides the storage space used by the host CPU 34 and
It stores the programs and parameters required to operate the.

The terminal 10, in particular its GPS module 18
Is controlled by server commands and local commands. Among these commands, the server command is a command given from the LS 12, and the server command received by the PDC-P module 20 is basically passed through the host CPU 34 and the GPS module 1
8 are supplied. That is, the host C in this conventional technique
In principle, the PU 34, when recognizing that the server command has arrived, executes only the operation of transferring it to the GPS module 18, and modifies the server command.
Operations such as issuing local commands in response to server commands are not executed. The above-mentioned positioning instruction is a kind of server command, and the GPS satellite 1 to be the target of pseudorange measurement
6 ("Visible satellite number" in FIG. 5) and information such as the approximate value of the Doppler shift appearing in the signal from the GPS satellite 16 ("Doppler frequency" in FIG. 5). In principle, the response of the GPS module 18 to the server command also passes through the host CPU 34.

On the other hand, the local command is GP
This is a command related to the operation of the S module 18 that does not need to be supported via the network 14, and is issued by the host CPU 34. For example, it is a command relating to the setting of the frequency of the clock to be used, the setting of TXACTV valid / invalid, various calibration operations, operation state monitoring and the like. In Fig. 5, "various settings" refer to clock frequency and TXA.
This is a local command for CTV. The response of the GPS module 18 to this, for example, “positioning end notification” in FIG. 5 is terminated by the host CPU 34. The TXACTV is a PDC-P module 20.
Is a signal indicating that is being transmitted, and is supplied by the PDC-P module 20. TXACTV = in "various settings"
If set to valid, DS in GPS module 18
P32 masks GPS during TXACTV generation (described later).

As shown in FIG. 5, when the power of the terminal 10 is turned on by, for example, a switch operation of the owner, the host CPU 34 turns on the GPS module 18 and the like. Immediately after that, the host CPU 34 issues a local command for initialization and various settings. Then LS
When the positioning instruction is transmitted from 12 and the PDC-P module 20 of the terminal 10 receives this, the positioning instruction is supplied to the GPS module 18 via the host CPU 34. The GPS module 18 sends the response to the PDC-P module 20 via the host CPU 34.
, And the PDC-P module 20 sends this response to the LS 12.

The GPS module 18 starts the operation within the alternate long and short dash line in FIG. 5 before and after the response to the positioning instruction. This operation is repeated the number of times specified by the LS 12 by the positioning instruction or another server command.

In this operation, first, the DSP 32 in the GPS module 18 starts power supply to the down converter 28 and clock supply to an A / D converter (not shown), and after a lapse of a predetermined time, for example, 1 second, Power supply to these down converters 28 and clock supply to an A / D converter (not shown) are stopped. The down converter 28 is a radio frequency circuit that down-converts and amplifies the signal received by the GPS antenna 24, and the A / D converter is a circuit that samples and quantizes this received signal at a predetermined frequency and supplies it to the DSP 32. Therefore, the DSP 32 can receive the digitized reception signal over the above-mentioned predetermined time. The DSP 32 stores this received signal in the snapshot RAM 30. In the present application, this operation of accumulating the received signal in the snapshot RAM 30 is called a snapshot, and the above-mentioned predetermined time during which the snapshot is executed is called a snapshot period.

The DSP 32 executes frequency analysis by a technique such as FFT (Fast Fourier Transform) on the received signal accumulated in the snapshot RAM 30 during the snapshot period after completion of the snapshot period, and derives a pseudo distance from the result. To do. Further, in frequency analysis, satellite signal enhancement processing by cumulative addition of received signals and frequency correction based on Doppler frequency during positioning instruction are performed to improve accuracy and sensitivity. The DSP 32 supplies the derived pseudo distance to the PDC-P module 20 via the host CPU 34, and the PDC-P module 20 transmits this to the LS 12.

After repeating the above operation, the DSP 32
Notifies the host CPU 34 of the end of processing. Host CP
After receiving the processing completion notification, the U34 stops the power supply to the GPS module 18 and the like.

The measurement (positioning) of the current position by such a method has an advantage over the conventional GPS positioning.
Particularly, since the signal from the GPS satellite 16 is snapshot and the pseudo range is derived by frequency analysis including signal enhancement by cumulative addition and Doppler frequency correction, -15
Even a weak signal of 2 dBm can be captured (improvement in sensitivity), and TTFF (Time To First Fix) can be shortened to about several seconds (TTFF reduction). Therefore, the pseudo distance can be measured by the terminal 10 and the current position of the terminal 10 can be calculated by the LS 12 even in a place where positioning is conventionally difficult, such as in a valley of a building, inside a wooden building, or in a car. In addition, the down converter 28 in the GPS module 18 and A /
Since the D converter and the like can be suspended except during the snapshot period, the battery lasts longer (power saving).

[0020]

However, the network-assisted GPS terminal for WAG developed so far has some problems. Among them, a major problem is that the signal to be received by the GPS module 18 is a weak signal, and unnecessary radiation and transmission waves from the host CPU 34 and the PDC-P module 20, etc.
If there is a level of colored noise that cannot be ignored, the S / N ratio of the received signal in the GPS module 18 will decrease. This causes an increase in the minimum receivable / capable reception level in the GPS module 18, that is, a decrease in sensitivity.

One of the unnecessary radiation / transmitted waves that causes the above is a transmitted wave by the PDC-P module 20.
That is, the PDC-P module 2 for communication with the LS 12
Even if the GPS module 18 receives a signal from the GPS satellite 16 and takes a snapshot while 0 is transmitting, the S / N ratio is increased by noise such as the transmitted wave from the PDC-P module 20 or its harmonics. Because of deterioration, it is difficult or impossible to derive the pseudo distance from the received signal on the snapshot RAM 30. As a measure against this phenomenon, a method called GPS mask by TXACTV has been conventionally proposed, but this method causes another problem.

That is, as shown in FIG. 4, the PDC-P module 20 has a TXA in addition to a clock for synchronization.
CTV is supplied to the GPS module. This TXA
CTV is a signal generated when the PDC-P module 20 is performing wireless transmission, that is, a signal indicating that transmission is in progress. The DSP 32 in the GPS module 18 is shown in FIG.
If TXACTV = valid is set in the "various settings", TXACTV is set on the PDC-P module 20.
The received signal is not taken in from the A / D converter while is generated. In FIG. 5, “masking GPS” indicates this operation. In the process of "masking GPS" by TXACTV, the transmission by the PDC-P module 20 is GP.
This is useful in preventing the S / N of the signal received by the S module 18 from being deteriorated, that is, in preventing potential self-interference. However, on the other hand, the received signal cannot be stored in the snapshot RAM 30 while the “GPS is masked”, and therefore the sensitivity improving effect by the cumulative addition is reduced. In addition, the fact that a circuit or software for generating the TXACTV must be mounted in the PDC-P module 20 also hinders cost reduction, device scale reduction, and power consumption reduction.

Unwanted radiation from the host CPU 34 is a further undesired radiation that causes the reception sensitivity of the GPS module 18 to decrease. As a countermeasure against this, conventionally, a method of electromagnetically shielding the control board 22 or at least the host CPU 34 has been proposed. However, this method not only adds components and assembly costs for the shield case, but also
The device scale of the terminal also becomes large. In addition, since the shielding performance of the shield case defines the limit of the effect of preventing unnecessary radiation interference, if the shielding performance of the shield case is inferior, the unnecessary radiation from the host CPU 34 cannot be effectively shielded, and G
It becomes an obstacle for the snapshot by the PS module 18.

As the unnecessary radiation that causes the reception sensitivity of the GPS module 18 to decrease, the PDC is further added.
There is unwanted radiation by the devices in the P module 20. This is a problem that does not become apparent unless a high-speed processor or the like is used in the PDC-P module 20, but such a device is incorporated in the PDC-P module 20 for the purpose of enhancing the function of the PDC-P module 20 or other purposes. Since there is a possibility of implementing, measures need to be taken. Undesired radiation by such a device and thus the received signal S at the GPS module 18
The / N reduction is achieved by electromagnetically shielding the PDC-P module 20 or the unnecessary radiation source device inside the PDC-P module 20.
While this can be mitigated, it introduces cost and other problems, as can be inferred from the previous discussion of control board 22.
Although transmission by the PDC-P module 20 can be dealt with by TXACTV, unnecessary radiation by a device in the PDC-P module 20 can occur even when transmission is not being performed. T
The method of GPS mask corresponding to XACTV is not effective.

The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to eliminate unnecessary radiation by a member that executes local control of a GPS module and transmission by a wireless module for wireless connection with a network. Or unnecessary radiation by the device in the wireless module is GP
By preventing the received signal from the S module from deteriorating and realizing it without using a shield case, TXACTV, etc., the sensitivity (S / N) of the GPS module is improved, the device scale is reduced, and the cost is reduced. Its purpose is to further promote power saving.

[0026]

In order to achieve such an object, the present invention provides (1) a wireless module for wirelessly connecting to a network to which an LS is connected, a pseudo range for a designated GPS satellite. A network-assisted GPS terminal in which a GPS module for measurement and a host processor that executes information exchange between the GPS module and a wireless module are housed in a single housing, wherein (2) LS is the network. In order to derive the current position of the assisted GPS terminal, the wireless module receives the positioning instruction including the GPS satellite designation by the LS via the network, and further supplies the positioning instruction to the GPS module via the host processor. Receives the signal from the GPS satellite specified by for a predetermined time and stores it in the memory Thereafter the signal on the memory in the network assisted GPS terminal for deriving pseudorange respect to its GPS satellites by frequency analysis, the (3) the host processor, at least the GPS module GP
At least one of a process of sleeping the host processor itself, a process of stopping transmission by the wireless module, and a process of sleeping the wireless module or a processor inside thereof over a period in which a signal from the S satellite is received, It is characterized by executing.

Alternatively, the present invention provides (1) a wireless module for wirelessly connecting to a network to which an LS is connected,
And a network-assisted GPS terminal in which a GPS module for measuring a pseudo range for a designated GPS satellite is housed in a single housing, and (2) LS indicates the current position of the network-assisted GPS terminal. In order to be able to derive, the wireless module receives the positioning instruction including the GPS satellite designation by the LS through the network, and further receives the GP.
The GPS module receives the signal from the GPS satellite designated by the positioning instruction for a predetermined time, stores it in the memory, and then frequency-analyzes the signal in the memory to supply the S satellite to the S satellite. In a network-assisted GPS terminal that derives pseudorange,
(3) While the wireless module executes control of the GPS module, at least during the period when the GPS module receives a signal from a GPS satellite, a process of stopping transmission by the wireless module itself, and causing the wireless module itself to sleep. At least one of a process and a process of causing a processor in the wireless module to sleep is executed.

As described above, in the present invention, unnecessary radiation that deteriorates the S / N of the signal received by the GPS module in the same terminal over at least the period when the GPS module receives the signal from the GPS satellite. The member that is the source of the transmitted wave is put to sleep or stopped. Therefore, it becomes possible for the GPS module to derive the pseudorange from the weak satellite signal which was conventionally buried by the unnecessary radiation or the transmitted wave. For example,
When the present invention is realized as a WAG terminal, -152
Since the pseudo range can be derived from a satellite signal having a level even lower than dBm, the pseudo range can be more easily and quickly measured in a place where it has been impossible or difficult to measure the pseudo range in the past.

Further, since the reception timing of the GPS module and the timing of generation of unnecessary radiation or transmission by the host processor, the radio module, etc. are deviated, it is not necessary to use the shield case used conventionally. Further, since the GPS is not masked when the wireless module is transmitting, the transmission by the wireless module is prohibited when the GPS module is receiving (for example, snapshot). A signal corresponding to this becomes unnecessary.

[0030]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below with reference to the drawings. Note that the same or corresponding configurations as those of the conventional technique shown in FIGS. 3 to 5 are denoted by the same reference numerals, and redundant description will be omitted. Further, the same reference numerals are given to the configurations common to the preferred embodiments of the present invention, and the duplicated description will be omitted.

FIG. 1 shows the configuration of the terminal 10A according to the first embodiment of the present invention. The terminal 10A according to the present embodiment,
The GPS module 18, the PDC-P module 20, the host CPU 34A and its RAM 36, ROM 38, and a battery (not shown) are housed in a single housing, and the GPS antenna 24 and the PDC antenna 26 are provided on the surface or inside of the housing. It has a different configuration. Host CPU3
4A is a conventional host CPU 34 to which the functions described later are added. Further, the external difference of this embodiment from the prior art shown in FIG. 4 is that the shield covering the control board 22 is eliminated and the host CPUs 34A, R
Members such as AM36 and ROM38 are GPS modules 18
In contrast, it is not electromagnetically shielded, and it is downsized accordingly. In the present embodiment, by eliminating the conventionally used shield case, the component cost, the assembly cost, etc. are reduced and the miniaturization is achieved.

The present embodiment does not simply eliminate the shield. In this embodiment, the host CPU 3
Host CP despite not shielding 4A
It is possible to prevent the S / N of the reception signal of the GPS module 18 from decreasing due to unnecessary radiation from the U34A. This is because the host CPU 34A, which performs local control of the GPS module 18 and mediates exchange of information between the PDC-P module 20 and the GPS module 18, takes a sleep state while the GPS module 18 is executing a snapshot. is there.

More specifically, the host CPU 34A is
The positioning instruction from the LS 12 received by the PDC-P module 20 passes through the host CPU 34A and G
After being supplied to the DSP 32 in the PS module 18, G
For example, for one second until the snapshot in the PS module 18 ends, the PS module 18 enters a sleep state itself. The snapshot takes 0.128 seconds to 1.28 seconds depending on the positioning instruction.
This is a process of receiving signals in the frequency band used by the GPS satellites 16 for 024 seconds and collecting received signals. Therefore, if the host CPU 34A is placed in the sleep state for about 1 second after the positioning instruction, the host CPU 34A during the snapshot period
The unnecessary radiation from 34A is suppressed, and the S / N ratio of the received signal due to the unnecessary radiation does not occur, or at least does not cause a problem. In the sleep state, for example, when the host CPU 34A executes a sleep command and stops execution of subsequent commands, the host CPU
It can be realized by various conventionally known means such as reduction of power supply voltage supplied to 34A, reduction of clock frequency, and stop of current supply to some elements. Returning from the sleep state can also be realized by conventionally known means.

As described above, in this embodiment, the GP
From the time when the positioning instruction is given to the S module 18, the host CPU 34A is put to sleep in anticipation of the time when the snapshot will be completed by the GPS module 18. That is, the host CPU 34A is in the sleep state while the GPS module 18 is executing the snapshot. Therefore, the host CPU3
It is not necessary to shield the board on which 4A or the host CPU 34A is mounted with a shield case or the like.
Moreover, although leakage of unwanted radiation through the shield case could occur in the past, such leakage cannot occur in the present embodiment, so the sensitivity is improved and the TTFF is shortened compared to the conventional case. Furthermore, the host CPU 34A in the present embodiment
Has entered a sleep state in response to a positioning instruction, which is a type of server command. In other words, the host CPU 34A in this embodiment has a function of using the server command. By adding a function to which this is applied / expanded to the host CPU 34A, various operations according to the server command can be executed by the host CPU 34A.

In the present embodiment, the host CPU 34A starts sleep for a predetermined period by using the positioning instruction as a trigger, but this may be changed to another method. For example, when the host CPU 34A intercepts and monitors the communication between the DSP 32 and various devices in the GPS module 18, and as a result detects a situation in which it can be determined that "snapshot start", the host CPU 34A may go to sleep. . Alternatively, a specific signal may be output from the DSP 32 at the time of starting a snapshot, and the host CPU 34A may be put to sleep in response to this signal. Alternatively, it is added to the GPS module 18 that the supply of the reception signal from the A / D converter in the GPS module 18 to the DSP 32 is stopped and the clock supply to the A / D converter is stopped. The host CPU 34A may detect the signal by the signal detecting member, and the host CPU 34A may go to sleep in response to the detection. Compared with these alternative methods, the method of the present embodiment, that is, the method of going to sleep in response to a positioning instruction has an advantage in that the hardware and software of the GPS module 18 do not need to be particularly modified. There is.

FIG. 2 shows the configuration of the terminal 10B according to the second embodiment of the present invention. In this embodiment, the host CPU 34, the RAM 36, and the ROM 38 according to the conventional technique are used.
A member corresponding to is provided in the PDC-P module 20A. Among the members constituting the PDC-P module 20A, the transmission / reception unit 40 is a member that transmits / receives a radio frequency signal using the PDC antenna 26, and the control unit 4
Reference numeral 2 is a member for controlling the transmitting / receiving operation of the transmitting / receiving unit 40. The CPU 34B is a member that performs local control of the GPS module 18 via the control unit 42, and corresponds to the host CPU 34 in the related art or the host CPU 34A in the first embodiment. CPU34B is G
While the PS module 18 is executing the snapshot, the control unit 42 is instructed to stop the transmission operation by the PDC-P module 20A, specifically, the operation of the transmission / reception unit 40. The determination / detection as to whether or not the GPS module 18 has started (is about to start) executing the snapshot follows the method exemplified above as the method for detecting the timing to enter sleep, including the same method as in the first embodiment. , CPU34B executes.

Therefore, in this embodiment, the transmission operation in the PDC-P module 20A is stopped while the snapshot is being executed in the GPS module 18, so that the GPS module 18 is transmitted by the transmission wave from the PDC-P module 20A. The S / N of the received signal due to does not decrease. Further, the configuration is such that the transmission operation by the PDC-P module 20A is stopped while the signal is being received by the GPS module 18, rather than the configuration in which the TXDCTV is supplied from the PDC-P module 20 to the GPS module 18 as in the conventional art. At TXAC
It is not necessary to generate a TV or a signal equivalent to it,
The circuit and software for that are unnecessary. Since the GPS is not masked, the effect of improving the sensitivity by accumulating and adding received signals cannot be reduced. Further, it is possible to provide a function of putting the CPU 34B to sleep during the snapshot by the GPS module 18, and in that case, the CPU 34B
It is possible to prevent the unnecessary radiation by B from deteriorating the S / N of the signal received by the GPS module 18.

As described above, in each of the embodiments of the present invention, the sensitivity and the T which are comparable to or superior to those of the prior art are obtained.
While realizing the TFF, it is possible to eliminate the shield case and the TXACTV and realize the downsizing of the device configuration and the cost reduction.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a terminal according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a terminal according to a second embodiment of the present invention.

FIG. 3 is a conceptual diagram showing a system configuration of a network-assisted GPS.

FIG. 4 is a block diagram showing a configuration of a conventional terminal.

FIG. 5 is a diagram showing an operation procedure of this terminal.

[Explanation of symbols]

10A, 10B terminal, 12 LS (location server), 14 network, 16 GPS satellites, 18
GPS module, 20, 20A PDC-P module, 24 GPS antenna, 26 PDC antenna, 2
8 Downcon, 30 Snapshot RAM, 3
2 DSP, 34A, 34B Host CPU, 36R
AM, 38 ROM, 40 transmitter / receiver, 42 controller.

Continued front page    F term (reference) 5J062 AA08 CC07 DD22 EE03                 5K067 BB04 BB36 DD20 EE02 EE10                       EE16 FF03 GG01 GG11 HH23                       JJ53 JJ56 KK05 KK13

Claims (2)

[Claims] 1. A wireless module for wirelessly connecting to a network to which a location server is connected, a GPS for measuring a pseudo range for a designated GPS satellite.
A network-assisted GPS terminal in which a module and a host processor that executes information exchange between the GPS module and the wireless module are housed in a single housing, and a location server is a current location of the network-assisted GPS terminal. So as to derive the GPS satellite, the wireless module receives the positioning instruction including the GPS satellite designation by the location server via the network and further supplies it to the GPS module via the host processor. The GPS module specifies the GPS satellite designated by the positioning instruction. In a network-assisted GPS terminal for deriving a pseudorange for a GPS satellite by receiving a signal from a GPS receiver for a predetermined time and storing it in a memory and then frequency-analyzing the signal in the memory, the host processor has at least a GPS Module is
At least one of a process of causing the host processor itself to sleep, a process of stopping transmission by the wireless module, and a process of causing the wireless module or a processor therein to sleep while the signal from the PS satellite is received. A network-assisted GPS terminal that is characterized by executing. 2. A network-assisted type in which a wireless module for wirelessly connecting to a network to which a location server is connected, and a GPS module for measuring a pseudo range for a designated GPS satellite are housed in a single housing. A GPS terminal, wherein the wireless module receives a positioning instruction including a GPS satellite designation by the location server via the network and further supplies it to the GPS module so that the location server can derive the current position of the network assisted GPS terminal. The GPS module receives a signal from a GPS satellite designated by a positioning instruction for a predetermined time and stores it in a memory, and then frequency-analyzes the signal in the memory to derive a pseudo range for the GPS satellite. No network-supported GPS terminal While the module executes control of the GPS module, a process of stopping transmission by the wireless module itself, a process of causing the wireless module itself to sleep, and a wireless process at least during the period when the GPS module receives a signal from a GPS satellite. A network-assisted GPS terminal, characterized in that it executes at least one of the processes for putting the processor in the module to sleep.