JP2010014485A - Gps signal generator and relay system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately detect a position without changing a configuration and an operation of a terminal even if it exists in an indoor environment in which it can not easily receive radio wave from a GPS satellite. <P>SOLUTION: A GPS signal generator includes: a GPS signal receiving section 11 for receiving a GPS signal from the GPS satellite; a position information storing section 15 for holding position information on a particular point regarding a position of the apparatus; and a pseudo GPS signal generating section 18 for adjusting transmission timing of the received GPS signal based on the position information, and generating a pseudo GPS signal having the same information and the same signal form as the GPS signal. The pseudo GPS signal generating section 18 determines transmission timing of the pseudo GPS signal by the timing generated by a navigation message timing generating section 17 based on the position information of the apparatus and a navigation message of the received GPS signal, and generating the pseudo GPS signal whose timing is adjusted by the same content as the received GPS signal. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a GPS signal generator and a relay system that can receive a GPS signal from a GPS (Global Positioning System) satellite indoors.

  In recent years, many mobile terminals such as mobile phone terminals are equipped with a position detection function using GPS. In Japan, a 3G mobile phone terminal released after April 2007 is required to incorporate a GPS module that realizes this position detection function in principle.

  The GPS position detection function receives a plurality of radio waves arriving from a plurality of satellites (referred to as GPS satellites) constituting the system, and receives radio waves based on a plurality of GPS signals included in these radio waves. The position of the reception point, that is, the latitude, longitude, and height of the user position is specified by calculation.

  Such a position detection function is generally used for navigation when a user of a terminal walks outdoors or moves using a vehicle such as an automobile. As another application, for example, when a user of a terminal is involved in some crime, it is also assumed that the terminal position information is reported and used for identifying the current position of the user. However, in a space surrounded by metal, such as inside a building where a reinforcing bar is embedded, or inside a steel-framed building, radio waves from originally weak GPS satellites are further attenuated. It is inevitable that it will be difficult. In a portable terminal, it is desired to be able to detect a position even in an environment where it is difficult to receive radio waves from GPS satellites such as indoors such as buildings, underground, and under an overpass. In particular, it is important to be able to detect the position regardless of the reception environment, for example, when it is desired to specify the current position of the user based on the terminal position information.

  For example, Patent Document 1 and Patent Document 2 are known as conventional techniques for enabling indoor position detection.

  Patent Document 1 discloses that a GPS signal received by a GPS antenna installed outdoors in a building is drawn indoors with a cable, and this GPS signal is directly re-radiated as a radio wave by a GPS transmitter installed indoors. . In the configuration of Patent Document 1, when a mobile phone terminal equipped with a GPS module exists indoors, it is difficult for the mobile phone terminal to directly receive radio waves transmitted from GPS satellites. By receiving radio waves from a certain GPS transmitter, the mobile phone terminal can acquire GPS signals necessary for position detection, and the position can be specified even indoors.

In Patent Document 2, a pseudo GPS signal having the same message structure as a GPS signal transmitted from a GPS satellite and including position data of a transmitter installation location is used instead of satellite orbit data (navigation message) included in the GPS signal. It is disclosed to provide a transmitter that transmits as radio waves. With the configuration of this Patent Document 2, even if indoors where radio waves from GPS satellites cannot be received, the position can be detected if the location can receive radio waves from the transmitter of the pseudo GPS signal.
JP 2005-244625 A JP 2006-20151 A

  However, in the technique of Patent Document 1, when a mobile phone terminal receives a GPS signal from a GPS satellite via a GPS transmitter installed indoors, the position detected by the mobile phone terminal is the GPS satellite. It becomes the position of the outdoor GPS antenna that receives the radio wave from. Therefore, when the mobile phone terminal is used indoors at a position far away from the outdoor GPS antenna, a large measurement error occurs at the detection position.

  In addition, when a GPS signal received by an outdoor GPS antenna is guided to various indoor locations using a long coaxial cable or the like, multipath may occur due to the influence of reflection or the like. In this case, the GPS signal affected by the multipath is directly re-radiated from the indoor GPS transmitter, so that the position detection error occurs due to the influence of the multipath when detecting the position in the mobile phone terminal. there's a possibility that.

  Moreover, in the technique of Patent Document 2, the pseudo GPS signal transmitted from a transmitter installed indoors or the like has a different information format from the GPS signal transmitted by a GPS satellite. For this reason, the position detection function mounted on the current mobile phone terminal and the like that is designed to process GPS signals transmitted from GPS satellites processes pseudo GPS signals transmitted from transmitters. I can't. In other words, even if the hardware of the circuit that receives the GPS signal can be used as it is, the contents of the signal processing, that is, the signal processing software is not changed in accordance with the format of the information included in the pseudo GPS signal. The position cannot be detected from this pseudo GPS signal.

  The present invention has been made in view of the above circumstances, and is in an environment where it is difficult to receive radio waves from GPS satellites such as indoors without changing the configuration and operation of a terminal having a position detection function by GPS. It is another object of the present invention to provide a GPS signal generator and a relay system that can accurately detect a position.

The present invention includes a GPS signal receiving unit that receives a GPS signal from a predetermined satellite that can be used for positioning of a receiving point, a position information holding unit that holds position information of a specific point related to the position of the own device, and the received Provided is a GPS signal generation device including a pseudo GPS signal generation unit that generates a pseudo GPS signal that is a signal obtained by adjusting the transmission timing of a GPS signal based on the position information and has the same information and signal format as the GPS signal. To do.
Thereby, a pseudo GPS signal in which the transmission timing is adjusted based on the position information regarding the position of the GPS signal generator is generated. Here, the position information may be information including at least latitude and longitude and further including height. A terminal having a GPS receiver can measure the current position by receiving a pseudo GPS signal, as in the case of directly receiving a GPS signal from a satellite. Therefore, it is possible to detect the position with high accuracy even in an environment where it is difficult to receive radio waves from GPS satellites such as indoors without changing the configuration and operation of the terminal having the position detection function by GPS. .

Further, the present invention is the above GPS signal generator, wherein the GPS signal receiving unit receives GPS signals from at least four satellites, and the pseudo GPS signal generating unit is a position of the four satellites. When the information is Xn, Yn, Zn (n is an integer of 1 to 4), the position information of the specific point is Ux, Uy, Uz, the speed of light is c, and the clock bias indicating the clock error is CB, Calculated time differences ΔT1, ΔT2, ΔT3, ΔT4
ΔT1 = (√ ((X1−Ux) ² + (Y1−Uy) ² + (Z1−Uz) ² )) / c + CB
ΔT2 = (√ ((X2−Ux) ² + (Y2−Uy) ² + (Z2−Uz) ² )) / c + CB
ΔT3 = (√ ((X3−Ux) ² + (Y3−Uy) ² + (Z3−Uz) ² )) / c + CB
ΔT4 = (√ ((X4−Ux) ² + (Y4−Uy) ² + (Z4−Uz) ² )) / c + CB
√ () includes one that determines the transmission timing of the pseudo GPS signal based on the square root in ().
Thereby, it is possible to determine and generate the transmission timing of the pseudo GPS signal based on the time difference calculated based on the positional information including the latitude, longitude, and height related to the position of the GPS signal generating device. Even in an environment where it is difficult to receive radio waves from the GPS, it is possible to accurately detect the position of latitude, longitude, and height using a pseudo GPS signal.

Further, the present invention is the above GPS signal generator, wherein the GPS signal receiving unit receives GPS signals from at least three satellites, and the pseudo GPS signal generating unit is a position of the three satellites. When the information is Xn, Yn (n is an integer of 1 to 3), the position information of the specific point is Ux, Uy, the speed of light is c, and the clock bias indicating the clock error is CB, the time difference calculated by the following equation ΔT1, ΔT2, ΔT3
ΔT1 = (√ ((X1−Ux) ² + (Y1−Uy) ² )) / c + CB
ΔT2 = (√ ((X2−Ux) ² + (Y2−Uy) ² )) / c + CB
ΔT3 = (√ ((X3−Ux) ² + (Y3−Uy) ² )) / c + CB
√ () includes one that determines the transmission timing of the pseudo GPS signal based on the square root in ().
Thereby, the transmission timing of the pseudo GPS signal can be determined and generated based on the time difference calculated based on the position information including the latitude and longitude regarding the position of the GPS signal generator, and the radio wave from the GPS satellite such as indoors can be generated. Even in an environment where it is difficult to receive, it is possible to detect the position of latitude and longitude with high accuracy by the pseudo GPS signal.

Further, the present invention is the above GPS signal generator, wherein the GPS signal receiving unit receives a GPS signal including a navigation message encoded by a C / A (Coarse and Acquisition) code from the satellite. A C / A code suitable for the GPS signal is determined, and the pseudo GPS signal generation unit includes a unit that generates a pseudo GPS signal to which the same C / A code as the determined C / A code is assigned.
This makes it possible to generate a pseudo GPS signal that has the same information and signal format as the GPS signal from the satellite and can be handled in the same way as the GPS signal.

Further, the present invention is the above GPS signal generator, wherein the pseudo GPS signal is transmitted by radio waves, the GPS signal from the satellite is received at a predetermined position, and the pseudo GPS signal and the GPS signal are received. An interference detection GPS receiver that detects interference with the GPS, and the transmitter adjusts the transmission output of the pseudo-GPS signal according to the reception intensity of the GPS signal received by the interference detection GPS receiver Including what to do.
Thereby, the pseudo GPS signal and the GPS are adjusted by adjusting the transmission output of the pseudo GPS signal according to the reception intensity of the GPS signal from the satellite at a predetermined position, for example, near the boundary of the area of the transmission range of the pseudo GPS signal. Interference with a signal can be suppressed.

Further, the present invention provides any one of the GPS signal generators described above, a GPS antenna for receiving GPS signals from the satellites, and the received GPS signals obtained from the pseudo GPS signals generated by the GPS signal generators. There is provided a relay system including a radio unit that converts radio signals of the same frequency and a GPS relay antenna that transmits a pseudo GPS signal output from the radio unit to a predetermined area.
This makes it possible to detect the position with high accuracy even in an environment where it is difficult to receive radio waves from GPS satellites, such as indoors, without changing the configuration and operation of a terminal having a position detection function using GPS. A GPS signal relay system can be realized.

Further, the present invention provides a GPS antenna for receiving a GPS signal from a predetermined satellite that can be used for positioning of a receiving point, a communication receiving antenna for receiving a communication signal from a mobile communication base station, A frequency converter that converts the frequency of the received GPS signal to 300 MHz or less, and the communication receiving antenna and the GPS antenna are connected to each other via a cable, and the received communication signal and the frequency-converted GPS signal are reproduced. A relay station base unit for transmitting, any one of the GPS signal generators, a radio unit for converting a pseudo GPS signal generated by the GPS signal generator into a radio signal having the same frequency as the received GPS signal, and A GPS relay antenna that sends a pseudo GPS signal output from the radio unit to a predetermined area, and a communication relay that sends the communication signal to a predetermined area Providing a relay system comprising a relay Tsuboneko machine, a and a container.
As a result, a relay system including a GPS signal relay system can be configured in a mobile communication relay system, and mobile communication and GPS can be performed in a mobile phone or other terminal even in an environment where it is difficult to receive radio waves such as indoors. It becomes possible to perform the position detection by using a good state. In this case, since a cable or the like can be shared, the configuration can be simplified and the cost can be reduced.

  According to the present invention, it is possible to detect a position with high accuracy even in an environment where it is difficult to receive radio waves from a GPS satellite such as indoors without changing the configuration and operation of a terminal having a position detection function by GPS. It is possible to provide a GPS signal generation device and a relay system that can perform the same.

  First, a general technique related to a positioning system using GPS will be described as a prerequisite technique in the embodiment of the present invention.

(GPS positioning system)
The GPS (Global Positioning System) is a satellite navigation system operated by the US military and is composed of 18 to 24 MEO satellites. As a system including the GPS, there is a GNSS (Global Navigation Satellite System). GNSS is a satellite navigation system defined by ICAO (International Civil Aviation Organization) and has performance (accuracy and reliability) that can be used for civil air navigation. Specifically, it is a GPS / GLONASS + reinforcement system, and is generally a generic name for GPS / GLONASS / Galileo / various reinforcement systems.

  There are three signals (L1: 1575.42 MHz, L2: 1227.60 MHz, L3: 117.45 MHz) of GPS signals transmitted from GPS satellites, but generally used. Only L1. GPS signals transmitted by a plurality of GPS satellites are transmitted in a state of being multiplexed on the same frequency by CDMA (Code Division Multiple Access). When the number of satellites is 24, 24 signals are multiplexed on the L1 frequency. The GPS signal includes a navigation message (Satellite Message) consisting of data such as satellite orbit information and clock correction information (Ephemeris), orbit information of all satellites (Almanac), etc. . The L1 wave includes two types of signals, a signal encoded with a C / A (Coarse and Acquisition) code and a signal encoded with a P (Precision) code. The L2 wave includes a signal encoded with a P code. The random number pattern of the C / A code is publicly available.

  FIG. 10 is a schematic diagram showing an example of the positional relationship between GPS satellites and reception points and the timing of GPS signals. Here, as shown in FIG. 10A, it is assumed that the GPS receiver can receive radio waves from four GPS satellites at the receiving point whose position is to be measured. In this case, even when four GPS satellites transmit GPS signals at the same time, the positions of the GPS satellites are different from each other, so that there is a time difference in the time at which each GPS signal is received at the reception point.

As shown in FIG. 10B, the time at which the GPS signal from the first satellite is received is delayed by a time difference ΔT1 with respect to the predetermined reference time, and the time at which the GPS signal from the second satellite is received is predetermined. A time difference ΔT2 is delayed with respect to the reference time, a time at which the GPS signal from the third satellite is received is delayed by a time difference ΔT3 with respect to a predetermined reference time, and a time at which the GPS signal from the fourth satellite is received It is assumed that the time difference ΔT4 is delayed with respect to the predetermined reference time. In this case, the distances (pseudo distances) PR1, PR2, PR3, and PR4 between the reception point and each GPS satellite are obtained by the following equations.
PR1 = ΔT1 × c
PR2 = ΔT2 × c
PR3 = ΔT3 × c
PR4 = ΔT4 × c (1)
Where c is a constant corresponding to the speed of light

  However, in addition to the actual distance between the satellite and the user (reception point), the pseudorange calculated in this way includes satellite clock bias, atmospheric distortion, relativistic effects, receiver noise, receiver clock bias. Such errors are included. Therefore, before entering the process of determining the position and time, the pseudorange is subjected to deterministic correction to compensate for the error.

On the other hand, the GPS message navigation message transmitted from each GPS satellite also includes information indicating the position of each satellite. Therefore,
X1: X coordinate (latitude) for the position of the first satellite
Y1: Y coordinate (longitude) for the position of the first satellite
Z1: Z coordinate (height) for the position of the first satellite
X2: X coordinate relating to the position of the second satellite Y2: Y coordinate relating to the position of the second satellite Z2: Z coordinate relating to the position of the second satellite X3: X coordinate relating to the position of the third satellite Y3: Third satellite Y coordinate relating to the position of the third satellite Z3: Z coordinate relating to the position of the third satellite X4: X coordinate relating to the position of the fourth satellite Y4: Y coordinate relating to the position of the fourth satellite Z4: Z coordinate relating to the position of the fourth satellite Ux : X coordinate related to the user position Uy: Y coordinate related to the user position Uz: Z coordinate related to the user position CB: Clock bias of the GPS receiver c: If defined as a constant corresponding to the speed of light, simultaneous equations by four distance equations shown below Is established.
(X1−Ux) ² + (Y1−Uy) ² + (Z1−Uz) ² = (PR1−CB × c) ²
(X2−Ux) ² + (Y2−Uy) ² + (Z2−Uz) ² = (PR2−CB × c) ²
(X3-Ux) ² + (Y3-Uy) ² + (Z3-Uz) ² = (PR3-CB × c) ²
(X4-Ux) ² + (Y4-Uy) ² + (Z4-Uz) ² = (PR4-CB × c) ²
(2)

  Accordingly, by solving the simultaneous equations by applying the time differences ΔT1, ΔT2, ΔT3, and ΔT4 of the GPS signals detected in PR1 to PR4 of the above simultaneous equations, the coordinates of the user position (Ux, Uy, Uz) can be calculated.

  FIG. 11 is a waveform diagram showing a configuration of a GPS signal transmitted from a satellite. FIG. 11 shows a GPS signal (L1, C / A) actually transmitted from a GPS satellite. In this GPS signal, an L1 carrier having a frequency of 1575.42 MHz is modulated with a PN code (pseudo noise code) of 1.023 Mcps, and the PN code is modulated with a navigation message having a bit rate of 50 bps.

  As shown in FIG. 12, the receiver receives a GPS signal (PN code) transmitted from the satellite in a delayed state. FIG. 12 is a schematic diagram showing a general operation for detecting the delay time of the GPS signal received by the terminal. In order to correctly measure the delay time of the GPS signal, a replica signal having the same sign as that of the received wave is generated in the receiver, and the correlation between the received wave and the replica signal is obtained, and the replica signal is set so that the time difference τ becomes zero. Adjust the timing and detect the timing of the received wave.

  On the other hand, a GPS message navigation message as shown in FIG. 13 is transmitted from each GPS satellite. FIG. 13 is a schematic diagram showing a configuration of a navigation message included in a GPS signal transmitted from a satellite. From each GPS satellite, a navigation message consisting of 1500 bits of information is sent in one frame that is a combination of five subframes each consisting of 300 bits of information. In this case, since the bit rate is 50 bps, it takes 30 seconds to receive a navigation message of one frame. Subframes # 1 to # 3 include the clock / orbit information (ephemeris information) of the transmitting satellite itself, and the same contents are repeated every 30 seconds. Subframes # 4 and # 5 include rough clock / orbit information (almanac information) of other satellites, ionospheric correction information, etc., and information on 25 pages (frames) in total is sequentially displayed in each frame. Sent. Therefore, it takes 12.5 minutes to obtain information on all satellites.

  In order to receive the GPS signals transmitted from a plurality of GPS satellites and measure the position of the reception point, various pieces of information are required as described above, and it takes a relatively long time to receive these pieces of information ( Initial position calculation time (TTFF)) is required. Here, when the previously received information is stored in the nonvolatile memory and can be used, the position can be measured in a relatively short time. A general GPS receiver has the following three states in order to shorten the positioning time.

1. Cold start: When there is no information in the non-volatile memory. It takes a few minutes to capture the ranging signal and get the navigation message.
2. Warm start: When there is only almanac information in the nonvolatile memory. After capturing the ranging signal, it takes 30 to 60 seconds to obtain the navigation message.
3. Hot start: When the ephemeris information in the nonvolatile memory is valid. The distance measurement signal can be captured and the position can be calculated within a few seconds.

(Embodiment)
Next, embodiments according to the GPS signal generator and relay system of the present invention will be described.

  FIG. 1 is a block diagram showing a configuration example of a GPS signal generation device and a relay system according to an embodiment of the present invention. The GPS signal generator and relay system of the present embodiment are arranged indoors such as in a building and relay a GPS signal to a terminal located at a position where it is difficult to receive radio waves from GPS satellites. At this time, the GPS signal generation device generates and transmits a pseudo GPS signal in which the delay time of the signal is adjusted according to the installation position in the same format as the GPS transmitted from the GPS satellite as a relay GPS signal. .

  The relay system of the present embodiment is configured by arranging a plurality of GPS signal generators 10-1, 10-2, 10-3. Hereinafter, the plurality of devices may be described as the GPS signal generation device 10 as a representative. The GPS signal generators 10-1, 10-2, and 10-3 are installed in different indoor locations, and are connected to a common GPS signal receiving GPS antenna 101 via a coaxial cable 33. Each of the GPS signal generators 10-1, 10-2, and 10-3 includes transmission antennas 102-1, 102-2, and 102-3 that function as GPS relay antennas, and is received by the GPS antenna 101. The pseudo GPS signal generated by the own device based on the GPS signal from the received satellite is transmitted from each position.

  The GPS signal generator 10-1 determines the directivity so as to reach the range of the area A1 from the antenna 102-1, and radiates the radio wave of the pseudo GPS signal. Similarly, the GPS signal generator 10-2 radiates a radio wave of a pseudo GPS signal so as to reach the area A2 from the antenna 102-2, and the GPS signal generator 10-3 ranges from the antenna 102-3 to the area A3. The pseudo-GPS signal radio wave is radiated to reach Here, the positions and sizes of the regions A1, A2, and A3 are determined in advance so that the ranges do not overlap each other.

  As for the pseudo-GPS signal generated by the GPS signal generator 10-1, the reception timing of the GPS signal at the GPS antenna 101, the installation position of the GPS antenna 101, and the position of the installation position of the transmission antenna 102-1. The delay time is adjusted based on the information. Similarly, the pseudo GPS signal generated by the GPS signal generator 10-2 is based on the position information of the antenna 102-2, and the pseudo GPS signal generated by the GPS signal generator 10-3 is the position information of the antenna 102-3. Generate based on each. As a result, in each of the areas A1, A2, and A3 covered by the GPS signal generator 10, when a pseudo GPS signal is received by the terminal, the delay time corresponds to the actual position of the reception point. As in the case where the GPS signal is directly received from the mobile phone, the current accurate position information can be obtained at a terminal such as a mobile phone terminal even indoors.

  FIG. 2 is a schematic diagram showing an arrangement configuration example of the GPS signal generation device and the relay system according to the present embodiment. The GPS signal generation device and the relay system according to the present embodiment shown in FIG. 1 are disposed in a building 110 such as a building and relay GPS signals indoors. The GPS antenna 101 is disposed on the roof of the building 110 or the like so that radio waves from GPS satellites can be received satisfactorily. A plurality of GPS signal generators 10 are provided for each area such as each level in the building 110 and cover a wide area in the building 110. All the GPS signal generators 10 are connected in common with the antenna 101 via the coaxial cable 33. As described above, the relay system in which the GPS signal generating device is arranged makes it possible to acquire accurate position information using the GPS signal by the terminal even in the building 110 where the GPS signal from the satellite cannot be directly received. .

  Next, a specific configuration and operation of the GPS signal generation device according to the present embodiment will be described. FIG. 3 is a block diagram showing the configuration of the GPS signal generator of the present embodiment.

  The GPS signal generator 10 of the present embodiment includes a GPS signal receiver 11, a navigation message extractor 12, a reference timing extractor 13, a navigation message storage 14, a position information storage 15, a navigation message timing generator 17, a pseudo A GPS signal generation unit 18, a radio unit 19, and a transmission antenna 102 are provided. The GPS signal generator 10 is connected to the GPS antenna 101 and inputs a GPS signal from a satellite received by the GPS antenna 101. The GPS antenna 101 is an antenna for receiving a radio wave (L1: 1575.42 MHz signal) transmitted from each GPS satellite, and a place where the radio wave from the satellite is easily received (outdoors) such as a rooftop of a building. Installed.

  The GPS signal receiving unit 11 inputs the GPS signal received by the GPS antenna 101 via a coaxial cable or the like, and performs signal processing for receiving the GPS signal (L1). The navigation message extraction unit 12 detects the dominant four or more satellites having good reception status among the securable satellites, and the navigation message for each GPS signal (L1) from the detected satellites. Extraction in real time. Further, the C / A code encoding each navigation message is determined. The navigation message storage unit 14 includes a storage device composed of a nonvolatile memory or the like, and stores each navigation message extracted by the navigation message extraction unit 12 together with a C / A code assigned thereto. The content to be saved is sequentially updated each time the navigation message extraction unit 12 receives new navigation message information.

  The reference timing extraction unit 13 extracts a reference timing from the GPS signal (L1) received by the GPS signal reception unit 11. This reference timing is a certain timing corresponding to the reference time for measuring the time differences ΔT1, ΔT2, ΔT3, and ΔT4 of the GPS signals from the respective GPS satellites. Further, the reference timing extraction unit 13 determines the offset values of ΔT1, ΔT2, ΔT3, and ΔT4 so that the navigation message transmission timing of the GPS satellite coincides with the navigation message transmission timing of the GPS signal generator.

  The position information storage unit 15 realizes the function of the position information holding unit, and includes a storage device such as a nonvolatile memory. Holds location information (latitude, longitude, height). This position information is information indicating the location of a predetermined area covered by the own apparatus (transmission position of the pseudo GPS signal). For example, according to an instruction from the external apparatus 16 such as a personal computer, information on an appropriate position is provided. Is assigned. That is, information indicating the position coordinates of a predetermined point where the GPS signal generator 10 is installed is registered in the position information storage unit 15.

  The navigation message timing generation unit 17 holds the reference timing extracted from the GPS signal by the reference timing extraction unit 13, the position information of the user position held by the position information storage unit 15, and the navigation message storage unit 14. Based on the content of the navigation message, the timing related to each of the plurality of pseudo GPS signals corresponding to the GPS signals from the respective GPS satellites is determined and generated.

  The pseudo GPS signal generation unit 18 generates a plurality of pseudo GPS signals corresponding to the GPS signals from the respective GPS satellites according to the timing generated by the navigation message timing generation unit 17. The wireless unit 19 amplifies the pseudo GPS signal generated by the pseudo GPS signal generation unit 18 and outputs it as a transmission signal, and the antenna 102 transmits the radio wave of the pseudo GPS signal into the area. At this time, the radio unit 19 converts the pseudo GPS signal generated by the pseudo GPS signal generation unit 18 into a radio signal having the same frequency as the GPS signal received by the GPS signal reception unit 11. The installation position of the antenna 102 may be set by selecting a place where the reception environment of radio waves at the terminal is good in the building 110 in the vicinity of the main body of the GPS signal generator 10 such as an indoor ceiling.

  FIG. 4 is a block diagram showing a configuration of a pseudo GPS signal generation unit in the GPS signal generation device of the present embodiment. In the example illustrated in FIG. 4, it is assumed that four pseudo GPS signals are generated using four independent pseudo GPS signal generation units 18-1, 18-2, 18-3, and 18-4. What is necessary is just to provide the pseudo GPS signal production | generation part 18 suitably according to the number of the pseudo GPS signals to produce | generate.

  The pseudo GPS signal generator 18 includes an L1 carrier generator 21, a C / A code generator 22, a NAV message generator 23, a clock generator 24, a 90-degree phase shifter 25, a multiplier 26, a multiplier 27, and an adder. 28.

  The L1 carrier generation unit 21 generates an L1 carrier having the same frequency (1575.72 MHz) as the received GPS signal. The C / A code generation unit 22 generates the same C / A code as the C / A code used for encoding the GPS signal corresponding to the pseudo GPS signal to be generated. The NAV message generation unit 23 generates a message having the same content as the navigation message of the GPS signal corresponding to the pseudo GPS signal to be generated. These C / A codes and navigation messages are held in the navigation message storage unit 14.

  The clock generation unit 24 may implement a high-accuracy clock such as OCXO, or may generate a highly accurate and stable clock by synchronizing with a high-accuracy clock extracted from a GPS satellite. The clock generated by the clock generator 24 is used by the L1 carrier generator 21, the C / A code generator 22, and the NAV message generator 23 to operate. The timing for generating the clock pulse is determined by the timing generated by the navigation message timing generation unit 17. The multiplier 26 multiplies the output of the C / A code generator 22 and the output of the NAV message generator 23 to encode the navigation message with the C / A code. The 90 degree phase shifter 25, the multiplier 27, and the adder 28 modulate the L1 carrier according to the encoded navigation message obtained as the output of the multiplier 26. Thereby, one pseudo GPS signal is generated as an output of the adder 28.

  In other words, the pseudo GPS signal generated by each pseudo GPS signal generation unit 18 uses the same carrier wave as the GPS signal (L1) received by the GPS signal generator 10, and is used to encode the received GPS signal. It is encoded using the same code as the C / A code and includes the same information as the navigation message of the received GPS signal. However, the timing of the pseudo GPS signal is slightly different from the received GPS signal because it is corrected in accordance with the position information held by the position information storage unit 15.

  In the pseudo GPS signal generation unit 18 shown in FIG. 4, only the L1 signal encoded with the C / A code among the GPS signals is generated as the pseudo GPS signal, but P (Precision) of the L1 signal is generated. The configuration of the pseudo GPS signal generation unit 18 may be changed so as to generate a signal encoded with a code or a signal encoded with a P code of the L2 signal.

  In order to enable detection of latitude, longitude, and height, at least four GPS signals or pseudo GPS signals are required. Therefore, it is necessary to implement four or more circuits for the pseudo GPS signal generation unit 18. . However, for example, in the case of flat ground, the height information can be replaced with a constant, so that at least three GPS signals or pseudo GPS signals can be used to measure the position of latitude and longitude. Therefore, the number of circuits of the pseudo GPS signal generation unit 18 may be three.

  Next, the timing of the pseudo GPS signal generated in the GPS signal generation device 10 of the present embodiment will be described in detail. FIG. 5 is a time chart showing an example of the timing of the GPS signal received by the GPS signal generator according to the present embodiment or the pseudo GPS signal output by the GPS signal generator.

For example, when the GPS signal generator 10 receives four GPS signals from four GPS satellites, four time differences ΔT1, ΔT2, ΔT3 from the four GPS signals as time differences with respect to the reference timing as shown in FIG. , ΔT4 is detected. However, since the time differences ΔT1, ΔT2, ΔT3, and ΔT4 in the received GPS signal correspond to the installation location of the GPS antenna 101 that is the reception point, there is a large difference from the current position of the indoor terminal. Therefore, in the GPS signal generation device 10 that relays the GPS signal and transmits the pseudo GPS signal, the time difference ΔT1, in accordance with the position information corresponding to the installation position of the own device (antenna 102) stored in the position information storage unit 15, A pseudo GPS signal in which ΔT2, ΔT3, and ΔT4 are corrected is generated. For this reason, the four pseudo GPS signals to be generated are also slightly adjusted in timing at a timing very similar to the signal shown in FIG.
Further, as described above, the offset values of the time differences ΔT1, ΔT2, ΔT3, and ΔT4 are adjusted and transmitted so that the navigation message timing of the GPS satellite and the navigation message transmission timing of the GPS signal generator are substantially matched. .

In the navigation message timing generation unit 17, the time differences ΔT 1, ΔT 2, ΔT 3, ΔT 4 of the respective pseudo GPS signals are actually determined as follows:
ΔT1 = (√ ((X1−Ux) ² + (Y1−Uy) ² + (Z1−Uz) ² )) / c + CB
ΔT2 = (√ ((X2−Ux) ² + (Y2−Uy) ² + (Z2−Uz) ² )) / c + CB
ΔT3 = (√ ((X3−Ux) ² + (Y3−Uy) ² + (Z3−Uz) ² )) / c + CB
ΔT4 = (√ ((X4−Ux) ² + (Y4−Uy) ² + (Z4−Uz) ² )) / c + CB
√ () represents the square root in ()
...... (3)
here,
c: Speed of light (constant)
CB: clock bias (predetermined constant representing clock error)
Ux: position in the X-axis direction held by the position information storage unit 15 Uy: position in the Y-axis direction held by the position information storage unit 15 Uz: position in the Z-axis direction held by the position information storage unit 15 Position X1: Position in the X-axis direction for the first satellite Y1: Position in the Y-axis direction for the first satellite Z1: Position in the Z-axis direction for the first satellite X2: Position in the X-axis direction for the second satellite Y2 : Position in the Y-axis direction for the second satellite Z2: Position in the Z-axis direction for the second satellite X3: Position in the X-axis direction for the third satellite Y3: Position in the Y-axis direction for the third satellite Z3: 3 Position in the Z-axis direction for the 4th satellite X4: Position in the X-axis direction for the 4th satellite Y4: Position in the Y-axis direction for the 4th satellite Z4: Position in the Z-axis direction for the 4th satellite

  Since the clock bias CB in the GPS signal generator 10 is not 0, a time error corresponding to this appears in the timing of the pseudo GPS signal. However, when the terminal calculates the position, when correcting the clock bias that originally exists in the GPS receiver, the calculation includes the clock bias CB in the GPS signal generator 10, so that no problem occurs.

  The pseudo GPS signal generation unit 18 is based on the navigation message held by the navigation message storage unit 14 and each timing generated by the navigation message timing generation unit 17 (reference timing and time differences ΔT1, ΔT2, ΔT3, ΔT4). Four pseudo GPS signals are generated.

When only three latitudes and longitudes that do not include height are used and three pseudo GPS signals are generated, the time differences ΔT1, ΔT2, and ΔT3 of the pseudo GPS signals may be determined by the following equations.
ΔT1 = (√ ((X1−Ux) ² + (Y1−Uy) ² )) / c + CB
ΔT2 = (√ ((X2−Ux) ² + (Y2−Uy) ² )) / c + CB
ΔT3 = (√ ((X3−Ux) ² + (Y3−Uy) ² )) / c + CB
√ () represents the square root in ()
(4)

  FIG. 6 is a schematic diagram showing a positional relationship between the GPS signal generator according to the present embodiment and a plurality of GPS satellites. When the GPS antenna 101 is installed outside the building 110 such as a building and the GPS signal generators 10-1 and 10-2 are installed indoors as in the example of FIG. 6, the radio waves from the GPS satellites 41 to 44 are transmitted. The GPS signal is received by the GPS antenna 101, and the GPS signal generators 10-1 and 10-2 generate pseudo GPS signals based on the received GPS signals, and the pseudo GPS signals are radiated indoors as radio waves.

  In this case, the GPS signal generator 10 receives GPS signals from the GPS satellites 41 to 44 at the installation position of the GPS antenna 101, but is transmitted from the antenna 102 of the GPS signal generator 10 located indoors. The timing of the pseudo GPS signal is equivalent to the timing (phase difference) of the GPS signal when it is assumed that the GPS signal from the GPS satellites 41 to 44 is received directly at the position of the GPS signal generator 10. Therefore, a terminal such as a mobile phone terminal can measure the current position accurately by receiving the pseudo GPS signal transmitted from the GPS signal generator 10 instead of the GPS signal from the satellite and performing positioning. Become.

  Moreover, since the navigation message and other information contained in the pseudo GPS signal is equivalent to the GPS signal transmitted from the satellite, it is changed to the hardware configuration or software of the GPS receiver or mobile phone terminal currently used. Without adding, it is possible to receive the pseudo GPS signal as it is in the same way as the GPS signal and measure the position.

  In addition, when a terminal such as a mobile phone terminal for measuring the position moves between outdoors and indoors, the signal received by the terminal is switched from a GPS signal to a pseudo GPS signal or from a pseudo GPS signal to a GPS signal. become. However, since the pseudo GPS signal transmitted from the GPS signal generator 10 is equivalent to the GPS signal transmitted from the satellite except for the timing difference, the signal received by the terminal is changed from the GPS signal to the pseudo GPS signal, or When switching from the pseudo GPS signal to the GPS signal, the terminal does not need to perform a special process, and the position can be measured in the above-described “hot start” state. Therefore, the position measurement can be completed in a short time, and the position can be measured smoothly (substantially continuously) even when a terminal such as a mobile phone terminal moves between the outdoors and the indoors. it can. If the C / A code of the pseudo GPS signal is different from that of the GPS signal, it is necessary to re-acquire the navigation message, so the “hot start” state cannot be continued and the operation starts from “warm start”. .

  Next, the modification regarding the GPS signal generator of this Embodiment is shown. FIG. 7 is a schematic diagram showing the relationship between the pseudo GPS signal from the GPS signal generator and GPS signals from a plurality of GPS satellites and the terminal, and FIG. 8 is a schematic diagram showing a modification of the GPS signal generator of the present embodiment. It is. The modification shown in FIG. 8 has a function of adjusting the output of a pseudo GPS signal as an additional function of the GPS signal generator.

  As shown in FIG. 7, for example, when the GPS signal generation device 10 is installed near the boundary with the outdoors, the GPS that arrives from the GPS satellites 41 to 43 at the terminal within the cover area of the GPS signal generation device 10. When the signal is receivable, both the GPS signal radio wave 52 from the satellite and the pseudo GPS signal radio wave 53 from the GPS signal generator 10 reach the terminal 50 such as a mobile phone terminal. In this case, since the frequency and sign of the GPS signal and the pseudo GPS signal are common, the two signals interfere with each other.

  Therefore, the GPS signal generation device 10A of the modification shown in FIG. 8 has a function of adjusting the output of the pseudo GPS signal in the transmission unit, and prevents interference of the pseudo GPS signal. Connected to the GPS signal generator 10A is a monitor GPS receiver 55 used as an interference detection GPS receiver. The position where the GPS antenna 103 of the GPS receiver 55 is installed is assumed to be near the boundary of the range where the GPS signal from the satellite can be received, or near the area boundary of the transmission range of the pseudo GPS signal by the GPS signal generator 10A. For example, the GPS antenna 103 is installed near an indoor window. The GPS receiver 55 only needs to have a function of identifying whether the radio wave received by the GPS antenna 103 is a signal from a GPS satellite and a function of identifying the reception intensity. At this time, the reception intensity of the GPS signal and the pseudo GPS signal may be detected by turning on and off the output of the pseudo GPS signal from the antenna 102 of the GPS signal generation device 10A.

  When the GPS signal generator 10 </ b> A can receive the radio wave 54 of the GPS signal from the satellite in the GPS receiver 55, the reception intensity of the radio wave 53 of the pseudo GPS signal from the own device in the GPS receiver 55 becomes a predetermined value or less. As described above, the output power of the pseudo GPS signal is adjusted in the transmission unit. Specifically, an output power control function is installed in the wireless unit 19 and the output of the pseudo GPS signal is controlled according to the signal output from the GPS receiver 55.

  Thus, in the vicinity of the boundary between the cover area of the indoor GPS signal generator and the outdoors, the radio wave 54 of the GPS signal coming from the satellite and the radio wave 53 of the pseudo GPS signal from the GPS signal generator may interfere with each other. Therefore, the output of the GPS signal generator is reduced or stopped and output adjustment is performed to prevent interference at the terminal 50. That is, when radio waves coming from GPS satellites can be received with sufficient intensity, the output of the pseudo GPS signal from the GPS signal generator is suppressed.

  Next, a configuration example in which the GPS signal generation device of the present embodiment is applied to a relay system for mobile communication such as a mobile phone will be described. Here, a system for a mobile phone is illustrated. FIG. 9 is a block diagram showing a configuration example of a relay system for a mobile phone including the function of the GPS signal generator of the present embodiment. The relay system shown in FIG. 9 has a function of the GPS signal generation device of this embodiment in a mobile phone relay device installed indoors. Since indoors and underground such as buildings are difficult to receive radio waves from mobile phone base stations, a base station relay device is installed to relay mobile phone radio signals between outdoor base stations and mobile phone terminals. To do.

  This relay system 30 includes a mobile phone outdoor antenna 31 that functions as a communication receiving antenna, a GPS antenna 101, a repeater device 34 that functions as a relay station base unit (see, for example, Japanese Patent Application Laid-Open No. 2008-141408), and a frequency conversion unit. And a frequency converter 35 that functions as a plurality of relay station slave units 36-1, 36-2, 36-3, and 36-4. The relay system 30 includes a plurality of relay station slave units connected in series in a long way so that radio signals can be relayed over a wide indoor area.

  The outdoor antenna 31 and the GPS antenna 101 are connected to a common coaxial cable 33 via a mixer 32, and a signal is drawn indoors via the coaxial cable 33 and connected to a repeater device 34 and a frequency conversion device 35. Yes. Mobile phone radio signals transmitted and received by the outdoor antenna 31 are directly input and output to the repeater device 34 via the coaxial cable 33. The GPS signal (1.5 GHz) received by the GPS antenna 101 is input to the frequency conversion device 35. The frequency conversion device 35 converts the input 1.5 GHz GPS signal into a predetermined frequency having a frequency lower than that, amplifies it, and outputs it to the repeater device 34. As for the frequency of the GPS signal input to the repeater device 34, the frequency of 1.5 GHz is converted into another frequency and output so as not to affect the repeater device. For example, when the repeater device is a 2 GHz repeater device, the frequency may be converted to a frequency of 300 MHz or less so as not to affect the repeater device.

  A plurality of coaxial distributors 37 are connected to the output side of the repeater device 34 by a common connection cable 39. The repeater device 34 transmits and receives mobile phone communication signals via a coaxial cable. The coaxial distributor 37 is connected to the GPS signal generator 10 via the distributor 40. The GPS signal generator 10 generates a pseudo GPS signal by using the GPS signal received by the GPS antenna 101, and converts the pseudo GPS signal into a 1.5 GHz radio signal by the radio unit to function as a GPS relay antenna. Transmit from the antenna 102.

  By providing the GPS signal generator in the mobile phone relay system in this way, it becomes possible to relay both the communication signal of the mobile phone and the GPS signal to an area where radio waves are difficult to reach. In this case, since a coaxial cable or the like to the outdoor antenna can be shared, the configuration can be simplified and the cost can be reduced. Moreover, although there are many opportunities to use both a communication signal and a GPS signal in a cellular phone terminal or the like, communication and positioning can be performed indoors according to this system.

  As described above, according to the GPS signal generation device of the present embodiment, the pseudo GPS signal generated by the GPS signal generation device is received by a mobile phone terminal or the like equipped with a GPS position measurement function such as a GPS module. This makes it possible to detect an accurate position in a good reception state even indoors. At this time, it is difficult for the terminal to directly receive the radio wave from the GPS satellite indoors, but the pseudo GPS signal generated by the GPS signal generator is re-transmitted on the radio wave and relayed, so that the pseudo GPS signal is received. Can be received indoors and used in the same way as GPS signals from satellites for positioning.

  When a GPS signal is received and a position is measured, a predetermined simultaneous equation is generally used to calculate the time difference obtained from the timing of each received GPS signal and the position information of each satellite obtainable from the received GPS signal. Is applied to the position information (latitude, longitude, height) of the reception point, which is an unknown number. Even when the terminal receives the pseudo GPS signal indoors and measures the position, the timing of the pseudo GPS signal is used to specify the position of the reception point. In this case, if the GPS signal received by the GPS antenna installed outdoors is simply amplified and retransmitted indoors, the measured position becomes the installation position of the outdoor GPS antenna that is the reception point. Cannot identify the correct position. Therefore, a pseudo GPS signal whose transmission timing is adjusted is generated instead of the GPS signal in order to enable accurate positioning.

  The pseudo GPS signal is assigned the same C / A code as the C / A code assigned to the navigation message of the GPS signal received from each satellite. As a result, when the terminal measures the position using the GPS signal or the pseudo GPS signal, the signal received with the movement between the outdoor and the indoor is switched from the GPS signal to the pseudo GPS signal, or from the pseudo GPS signal. Even when the GPS signal is switched, the acquisition of the navigation message can be continued using the common C / A code.

  Here, the information and signal format included in the pseudo-GPS signal are equivalent to the GPS signal transmitted from the satellite, but only the transmission timing of the pseudo-GPS signal is corrected based on the position information regarding the installation position of the GPS signal generator. The Therefore, the configuration and operation on the terminal side required for receiving the pseudo GPS signal and measuring the position are the same as in the case of processing a normal GPS signal, and no hardware or software change is required. . That is, by using the currently used terminal as it is and receiving the pseudo GPS signal, it is possible to increase the accuracy of indoor position measurement. In addition, the GPS signal transmitted from the GPS satellite and the pseudo-GPS signal generated by the GPS signal generator are the same except for the transmission timing, so that the user with the terminal moves between the outdoors and the indoors. Thus, even when the reception of the GPS signal and the reception of the pseudo GPS signal are switched, it is not necessary to newly acquire necessary information, and the position can be measured in a short time.

  Further, by monitoring the reception intensity of the GPS signal from the satellite and adjusting the transmission output of the pseudo GPS signal, interference between the GPS signal from the satellite and the pseudo GPS signal can be suppressed. For example, in the vicinity of the boundary between a building and the outside, both the GPS signal from the satellite and the pseudo GPS signal transmitted from the GPS signal generator may be received, and the GPS signal and the pseudo GPS signal interfere with each other. there is a possibility. Therefore, the occurrence of interference can be suppressed by automatically changing the transmission intensity of the pseudo GPS signal according to the reception intensity of the GPS signal.

  Further, by applying the GPS signal generation device of the present embodiment to a relay station for mobile communication such as a mobile phone, a GPS relay system can be integrated into the relay station. By using this relay system, even in an environment where radio waves are difficult to receive, mobile communication and positioning by GPS can be performed in a good state at the terminal. Further, by guiding the communication signal and the GPS signal indoors through a common cable, the cable can be shared and the number of wirings can be minimized. At this time, by shifting the frequency band of the GPS signal to 300 MHz or less, the difference in frequency between the communication signal and the GPS signal is increased, and these interferences can be significantly suppressed.

  Thus, according to the present embodiment, even if the terminal is used indoors or the like where GPS signals cannot be directly received, the pseudo-GPS signal output from the GPS signal generator is received by the terminal. Thus, an accurate position can be measured in a good state. Since the pseudo GPS signal is equivalent to the GPS signal transmitted from a normal GPS satellite except for the transmission timing, the pseudo GPS signal is used as it is without changing the configuration and operation (hardware and software) on the terminal side. Positioning can be performed. In addition, since the timing of the pseudo GPS signal is corrected based on the position information regarding the installation position of the transmission antenna of the GPS signal generator, the GPS antenna for receiving the GPS signal from each GPS satellite is connected to the terminal such as the roof of the building. Even when it is installed at a location far away from the receiving point, an increase in position measurement error can be suppressed.

  It should be noted that the present invention is not limited to that shown in the above-described embodiment, and those skilled in the art can also make changes and applications based on the description and well-known techniques. By the way, it is included in the scope of seeking protection.

  The present invention makes it possible to detect a position with high accuracy even in an environment where it is difficult to receive radio waves from a GPS satellite such as indoors without changing the configuration and operation of a terminal having a position detection function by GPS. Therefore, the present invention is useful as a GPS signal generation device and a relay system that can receive GPS signals from GPS satellites indoors.

The block diagram which shows the structural example of the GPS signal generator which concerns on embodiment of this invention, and a relay system Schematic diagram showing an arrangement configuration example of a GPS signal generation device and a relay system according to the present embodiment The block diagram which shows the structure of the GPS signal generator of this Embodiment The block diagram which shows the structure of the pseudo | simulation GPS signal generation part in the GPS signal generator of this Embodiment. The time chart which shows the example of the timing of the GPS signal which the GPS signal generator which concerns on this Embodiment receives, or the pseudo GPS signal which a GPS signal generator outputs The schematic diagram which shows the positional relationship of the GPS signal generator which concerns on this Embodiment, and several GPS satellites The schematic diagram which shows the relationship between the GPS signal from the GPS signal generator which concerns on this Embodiment, the GPS signal from several GPS satellites, and a terminal. The schematic diagram which shows the modification of the GPS signal generator of this Embodiment Block diagram showing a configuration example of a relay system for a mobile phone including the function of the GPS signal generator of the present embodiment Schematic diagram showing an example of the positional relationship between GPS satellites and reception points and the timing of GPS signals Waveform diagram showing the configuration of the GPS signal transmitted from the satellite Schematic diagram showing a general operation for detecting the delay time of the GPS signal received by the terminal Schematic diagram showing the structure of the navigation message included in the GPS signal transmitted from the satellite

Explanation of symbols

10, 10-1 to 10-3, 10A GPS signal generator 11 GPS signal receiving unit 12 Navigation message extraction unit 13 Reference timing extraction unit 14 Navigation message storage unit 15 Position information storage unit 16 External device 17 Navigation message timing generation unit 18 , 18-1 to 18-4 Pseudo GPS signal generation unit 19 Radio unit 21 L1 carrier generation unit 22 C / A code generation unit 23 NAV message generation unit 24 Clock generation unit 25 90 degree phase shifter 26, 27 Multiplier 28 Addition 30 Relay system 31 Outdoor antenna 32 Mixer 33 Coaxial cable 34 Repeater device 35 Frequency converter 36-1 to 36-4 Relay station slave unit 37 Communication signal relay unit 38 Antenna 39 Connection cable 39a Optical fiber 39b Coaxial cable 41, 42 , 43, 44 GPS satellite 50 end End 52, 53, 54 Radio wave 55 GPS receiver 101, 103 GPS antenna 102, 102-1 to 102-3 Antenna 110 Building

Claims (7)

A GPS signal receiving unit that receives a GPS signal from a predetermined satellite that can be used for positioning of the receiving point;
A position information holding unit that holds position information of a specific point related to the position of the own device;
A pseudo GPS signal generator that is a signal obtained by adjusting the transmission timing of the received GPS signal based on the position information, and generates a pseudo GPS signal having the same information and signal format as the GPS signal;
A GPS signal generator. The GPS signal generator according to claim 1,
The GPS signal receiving unit receives GPS signals from at least four of the satellites,
The pseudo-GPS signal generation unit includes Xn, Yn, Zn (n is an integer of 1 to 4) position information of the four satellites, Ux, Uy, Uz, position information of the specific point, c light speed, c When the clock bias representing the error is CB, the time differences ΔT1, ΔT2, ΔT3, ΔT4 calculated by the following equations:
ΔT1 = (√ ((X1−Ux) ² + (Y1−Uy) ² + (Z1−Uz) ² )) / c + CB
ΔT2 = (√ ((X2−Ux) ² + (Y2−Uy) ² + (Z2−Uz) ² )) / c + CB
ΔT3 = (√ ((X3−Ux) ² + (Y3−Uy) ² + (Z3−Uz) ² )) / c + CB
ΔT4 = (√ ((X4−Ux) ² + (Y4−Uy) ² + (Z4−Uz) ² )) / c + CB
√ () is a GPS signal generator that determines the transmission timing of the pseudo GPS signal based on the square root in (). The GPS signal generator according to claim 1,
The GPS signal receiving unit receives GPS signals from at least three of the satellites,
The pseudo GPS signal generation unit is a clock that expresses position information of the three satellites as Xn, Yn (n is an integer of 1 to 3), position information of the specific point as Ux, Uy, light speed as c, and clock error. When the bias is CB, the time differences ΔT1, ΔT2, and ΔT3 calculated by the following equations:
ΔT1 = (√ ((X1−Ux) ² + (Y1−Uy) ² )) / c + CB
ΔT2 = (√ ((X2−Ux) ² + (Y2−Uy) ² )) / c + CB
ΔT3 = (√ ((X3−Ux) ² + (Y3−Uy) ² )) / c + CB
√ () is a GPS signal generator that determines the transmission timing of the pseudo GPS signal based on the square root in (). The GPS signal generator according to claim 1,
The GPS signal receiving unit receives a GPS signal including a navigation message encoded by a C / A (Coarse and Acquisition) code from the satellite and determines a C / A code suitable for the GPS signal;
The pseudo GPS signal generation unit is a GPS signal generator that generates a pseudo GPS signal to which the same C / A code as the determined C / A code is assigned. The GPS signal generator according to claim 1,
A transmitter for transmitting the pseudo GPS signal by radio waves;
A GPS reception unit for receiving an GPS signal from the satellite at a predetermined position, and detecting an interference between the pseudo GPS signal and the GPS signal;
The transmission unit is a GPS signal generation device that adjusts the transmission output of the pseudo GPS signal according to the reception intensity of the GPS signal received by the interference detection GPS reception unit. A GPS signal generator according to any one of claims 1 to 5;
A GPS antenna for receiving GPS signals from the satellite;
A radio unit that converts the pseudo GPS signal generated by the GPS signal generator into a radio signal having the same frequency as the received GPS signal;
A GPS relay antenna for sending a pseudo GPS signal output from the wireless unit to a predetermined area;
A relay system comprising: A GPS antenna for receiving a GPS signal from a predetermined satellite that can be used for positioning of the receiving point;
A communication receiving antenna for receiving a communication signal from a mobile communication base station;
A frequency converter that converts the frequency of the received GPS signal to 300 MHz or less;
A relay station base unit that is connected to the communication receiving antenna and the GPS antenna via a cable and retransmits the received communication signal and the GPS signal after the frequency conversion,
6. The GPS signal generator according to claim 1; a radio unit that converts a pseudo GPS signal generated by the GPS signal generator into a radio signal having the same frequency as the received GPS signal; and the radio A relay station slave having a GPS relay antenna that sends a pseudo GPS signal output from the unit to a predetermined area, and a communication relay antenna that sends the communication signal to a predetermined area;
A relay system comprising:

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