JP2007218651A - Retransmission device for positioning signal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve a system which requires less cost and is easily changeable, on the occasion of retransmitting a signal transmitted from a satellite to enable GPS positioning, in an environment to which the signal from the satellite is difficult to arrive. <P>SOLUTION: This retransmission device for receiving a signal from a GPS satellite 31 with an antenna 32, and performing its retransmission from an indoor antenna 38 through a transmission line 34, uses as the transmission line 34, a general-purpose digital transmission line such as a LAN, consequently converts the received signal by the antenna 32 into a digital signal by a signal conversion section 33 and transmits it to the transmission line 34, receives the digital signal from the transmission line 34 at a signal restoration section 36 and restores the GPS signal, and retransmits it from the antenna 38. Accordingly, connection by a coaxial cable is required only between each antenna 32, 38 and the conversion section 33 or the restoration section 36 arranged near the antenna, so time and labor for design and execution can be reduced, and material costs can also be reduced. This system requires less cost and is easily changeable. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a positioning signal retransmitting apparatus that retransmits a positioning signal such as a GPS signal to a room or basement where positioning by a mobile terminal equipped with a GPS positioning function is usually impossible or difficult.

  As a method for detecting the location of a person or an object, a satellite positioning system such as the GPS is widely used. In these positioning systems, a high frequency such as several GHz is usually used, and the received radio wave power is low, so that there is a problem that positioning cannot be performed if there is an obstacle. In recent years, in order to solve these problems, technologies such as high-sensitivity GPS or network-assisted GPS have been developed and used in devices such as mobile phones.

  In the high-sensitivity GPS, it is possible to detect even a weak GPS signal by removing noise by digital signal processing. In the network-assisted GPS, information necessary for signal detection is transmitted from the server to the GPS receiver side via the network, or a signal detected on the GPS receiver side is transmitted to the server, and positioning is performed on the server side. Methods such as performing calculations are taken. Although these technologies can receive weak GPS signals, they can only be used in wooden houses or narrow roads in urban areas, and usually spend a lot of time in situations where people live socially. There are still many places where positioning by GPS is still impossible in concrete buildings such as split buildings and underground malls.

  Therefore, as a system using GPS, for example, in a human location system used for confirming the location of a child or an elderly person, a child or an elderly person who has a GPS receiver is in a building such as a school or a hospital. In some cases, there is a big problem, such as being unable to confirm the whereabouts. In Japan, since 2007, mobile phone terminal devices have been required to be equipped with a GPS receiver so that the location of the call can be identified by calling 110, etc. desired.

  Therefore, Patent Document 1 proposes a conventional technique for solving such a problem. According to the prior art, as shown in FIG. 13, a GPS signal transmission device 11 serving as a plurality of pseudo-satellites is provided in a shielded environment, and the GPS simulator 12 including a computer processing device creates the environment. The mobile terminal can be used in the same environment as outdoors by distributing the GPS signal that will be received to each transmitter 11.

  However, in the above-described conventional technology, the GPS simulator 12 is originally used for the development of a GPS receiver, and there is a problem that it is expensive enough to cost several hundred to several tens of millions of yen. Therefore, more simply, as shown in FIG. 14, the signal from the GPS satellite 21 is received by the GPS antenna 22 installed on the roof, and retransmitted from the GPS antennas a1 to a3 appropriately installed indoors. Is conventionally used. Specifically, the signal received by the GPS antenna 22 is appropriately amplified by the amplifier 23 in accordance with the transmission path length, the number of distributions, and the like, and then drawn indoors or underground by the coaxial cable 24 to be branched / distributed. The signals are appropriately distributed by the devices b1 and b2 and given to the GPS antennas a1 to a3.

With this configuration, as a positioning result at the mobile terminal, the position of the GPS antenna 22 installed on the building roof can be obtained. Although there is some error, GPS positioning is not possible with an inexpensive configuration. Positioning can be made possible even where it was possible.
Japanese Patent No. 3421790

  The above-described conventional technology can be configured at low cost when the scale is relatively small. However, when the number of branches / distributions increases, expensive high-frequency components increase, construction costs increase, and specialist knowledge for handling high-frequency signals is required, resulting in expensive design. In addition, when making changes such as adding the GPS antennas a1 to a3 after construction once, there is a possibility that the part other than the changed part may be affected, and the design for the change is complicated and lacks flexibility. There is also a problem.

  Specifically, power is supplied to the coaxial cable 24 from the DC power supply p1 installed on the top floor to the amplifier 23 installed in the vicinity of the GPS antenna 22 via a DC power supply superimposer t1 called a bias terminal. Then, power is supplied to the amplifier 23 and the converter of the GPS antenna 22. On the other hand, DC power supply cutters c1 to c3 corresponding to the GPS antennas a1 to a3 are provided on the downstream side of the branch / distributors b1 and b2 so that the direct current does not leak to the GPS antennas a1 to a3. Further, when the transmission path length becomes long, an amplifier 25 is provided as necessary, and a DC power supply p2 and a DC power supply superimposing device t2 for supplying power to the amplifier 25 are provided.

  In order to connect various devices such as the branch / distributors b1 and b2, the DC power supply superimposing devices t1 and t2, and the DC power supply cutters c1 to c3, a high frequency connector is required. It is very expensive. In addition, the wiring and device design of the amplifier 24 and the accompanying DC power supply p2, the DC power supply superimposing devices t1 and t2, and the DC power supply cutters c1 to c3 require specialized knowledge for handling high-frequency signals, and the design becomes expensive.

  An object of the present invention is to provide a positioning signal retransmission apparatus that is low in cost and easy to change.

  The positioning signal retransmission apparatus of the present invention receives the positioning signal by receiving the positioning signal with the first antenna and retransmitting the signal from the second antenna via the transmission path. In a positioning signal retransmitting apparatus that enables positioning by a mobile terminal having a positioning function even in difficult environments, the transmission path is a general-purpose digital transmission path, and the received signal of the first antenna is a digital signal. A signal conversion unit that converts the signal into the digital transmission path, receives the digital signal from the digital transmission path, restores the positioning signal from the digital signal, and radiates the signal from the second antenna And a restoration unit.

  According to the above configuration, in order to enable positioning by a mobile terminal equipped with a positioning function in an environment where positioning signals such as signals from GPS satellites such as indoors and underground are difficult to reach, the positioning signals are re-transmitted. In transmitting, the signal for positioning received by the first antenna is not amplified by an amplifier and transmitted to the indoor or underground using a coaxial cable or the like. And transmitted through a general-purpose digital transmission line such as a LAN. The signal restoration unit that has received the digital signal restores the positioning signal from the digital signal and radiates the signal from one or more second antennas.

  Therefore, when retransmitting the positioning signal indoors or underground, the connection by the coaxial cable is made only between the antenna and the signal conversion unit or the signal restoration unit provided in the vicinity thereof. And a material cost can be reduced, and a re-transmission apparatus that is low in cost and easy to change can be realized.

  In the positioning signal retransmission apparatus of the present invention, the positioning signal is a signal from a GPS satellite, and the signal conversion unit converts the received signal of the first antenna into a digital signal. A digital conversion unit and a communication interface unit for transmitting the converted digital signal to the digital transmission line, and after down-converting the reception signal of the first antenna to a predetermined frequency band, the analog / digital conversion unit The signal restoration unit includes a communication interface unit that receives a digital signal from the digital transmission path and a digital / analog conversion unit that converts the received digital signal into an analog signal, Up-convert the restored analog signal to the same frequency as the positioning signal. Characterized in that it is configured with an up-converter to be supplied to the second antenna.

  According to the above configuration, the baseband component is impaired in the down-converter unit instead of transmitting a signal obtained by directly converting a signal with a high carrier frequency from a GPS satellite through a general-purpose digital transmission line such as a LAN. After down-converting to a carrier frequency with no signal, the up-convert unit restores the original carrier frequency to a higher carrier frequency.

  Therefore, although a down-conversion unit and an up-conversion unit are required, the bit rate of a signal transmitted through the digital transmission path can be suppressed to a low level, and the digital transmission path, analog / digital conversion unit, and digital / analog conversion unit The lower cost can be used and the total cost can be reduced.

  Furthermore, the positioning signal retransmission apparatus of the present invention includes a plurality of the first antennas, and the signal conversion unit, the signal restoration unit, and the second antenna are provided in a plurality of systems corresponding thereto, The signal conversion units and signal restoration units of a plurality of systems are connected to a common digital transmission path.

  According to the above configuration, since the positioning result by the mobile terminal is the position of the first antenna, in order to improve the positional accuracy, when a plurality of configurations for re-transmission associated with each other is provided, A system can be constructed at low cost by using a common digital transmission line for the signal conversion units and the signal restoration units of the multiple systems. In addition, the number of systems can be increased or decreased as necessary, and the system can be flexibly constructed.

  In the positioning signal retransmission apparatus of the present invention, the second antenna is installed in an elevator.

  According to the above configuration, the elevator has a constant latitude and longitude, and only the altitude changes. Therefore, by installing the first antenna directly above the elevator, the exact position on the plane can be known. The present invention is particularly suitable.

  Furthermore, the positioning signal retransmission apparatus according to the present invention is characterized in that the second antenna is installed in an underground mall.

  According to the above configuration, it is impossible to receive a GPS signal in an underground shopping street, and since it is generally spread over a considerably large area, a number of first antennas for reception and the corresponding number of retransmission credits can be obtained. In arranging the two antennas, the system configuration can be flexibly performed by connecting the signal conversion unit and the signal restoration unit corresponding to the first antenna of each system to a common digital transmission path.

  As described above, the positioning signal retransmission apparatus of the present invention enables positioning by a mobile terminal equipped with a positioning function in an environment where positioning signals such as signals from GPS satellites such as indoors and underground are difficult to reach. Therefore, when retransmitting the positioning signal, the positioning signal received by the first antenna is amplified by an amplifier and is not transmitted to the indoor or underground using a coaxial cable or the like. The signal is once converted into a digital signal by the signal conversion unit and transmitted through a general-purpose digital transmission line such as a LAN, and the signal restoration unit that receives the digital signal restores the positioning signal, and one or more Radiation from the second antenna.

  Therefore, when retransmitting the positioning signal indoors, underground, etc., the connection by the coaxial cable is made only between the antenna and the signal conversion unit or the signal restoration unit provided in the vicinity thereof, and the design and construction are performed. It is possible to reduce a labor and a material cost, and it is possible to realize a re-transmission apparatus that is low in cost and easy to change.

[Embodiment 1]
FIG. 1 is a diagram showing a schematic configuration of a positioning signal retransmission apparatus according to an embodiment of the present invention. In this retransmission apparatus, a signal from the GPS satellite 31 is used as a positioning signal. In general, the retransmission apparatus receives a signal from the GPS satellite 31 by a GPS antenna 32 as a first antenna, and once converts the received signal into a digital signal by a signal conversion unit 33. One or a plurality of signal restoration units 36 are connected to the digital transmission path 34 on each floor in a building 35 where signals from the GPS satellites 31 cannot be received, and can be distributed arbitrarily by transmitting to the transmission path 34. Then, the reconstructed GPS signal is radiated from the GPS antenna 38 which is the second antenna disposed in proximity via the coaxial cable 37, so that the GPS signal is retransmitted indoors where it is difficult to receive the GPS signal. It enables positioning by a mobile terminal equipped with.

  FIG. 2 is a functional block diagram of the signal conversion unit 33 and the signal restoration unit 36. The GPS antenna 32 installed at a place with a good view of the roof of the building 35 receives a signal from a GPS satellite, and the received signal is input to the signal conversion unit 33. In the present embodiment, it is assumed that the GPS antenna 32 uses an L1 wave (1.57542 GHz) widely used in consumer devices. The GPS antenna 32 and the signal conversion unit 33 may be integrated in the same casing, or may be configured to be provided with a connector and connected by a cable.

  The received signal input to the signal converter 33 is appropriately amplified by an amplifier or the like as necessary, and then down-converted to an intermediate frequency signal by the down-converter 41. The down-converted signal is converted into a digital signal by the analog / digital converter 42 and sent out from the communication interface 43 to the digital transmission path 34.

  FIG. 3 is a block diagram showing a specific configuration of the down-conversion unit 41. Since the L1 wave includes a 1.023 MHz CA code, the intermediate frequency is set to a frequency higher than this, and 3.48 MHz is used in the present embodiment. For this reason, the L1 wave is first down-converted to 1st IF (41.82 MHz) by the 1st LO (1533.6 MHz) from the local oscillator 45 in the first stage mixer 44, and passes through the intermediate frequency filter 46. To the mixer 47. Subsequently, in the second stage mixer 47, the 1st IF is down-converted to 2nd IF (3.48 MHz) by 2nd LO (38.34 MHz) from the local oscillator 48, and passes through the intermediate frequency filter 49. And output to the analog / digital converter 42. These are the same as those generally used in GPS receivers, and may be configured using commercially available RFICs for GPS receivers.

  The analog / digital converter 42 samples the 3.48 MHz 2nd IF at a frequency more than twice, for example, 7 MHz and the number of quantization bits is 1 bit or 2 bits, and converts the sampled digital signal. The two IF frequencies and sampling frequencies may be appropriately selected within a range in which a GPS signal (the L23 wave of 1.023 MHz) can be reproduced.

  On the other hand, the signal restoration unit 36 receives the digital signal from the digital transmission line 34 by the communication interface unit 51, restores it to an analog signal by the digital / analog conversion unit 52, and then the up-conversion unit 53 Bird is restored to restore the L1 wave (1.57542 GHz).

  FIG. 4 is a block diagram showing a specific configuration of the up-converting unit 53. As shown in FIG. The digital signal from the digital transmission line 34 is up-converted to 1st IF (41.82 MHz) by the 1st LO (38.34 MHz) from the local oscillator 55 in the first-stage mixer 54, and the intermediate frequency filter 56. To the mixer 57. Subsequently, in the second-stage mixer 57, the 1st IF is up-converted to an RF signal L1 wave (1.57542 GHz) by 2nd LO (1533.6 MHz) from the local oscillator 58, and the intermediate frequency filter 59 Through the GPS antenna 38. These are the same as the configuration of a general transmitter. The signal restoration unit 36 and the GPS antenna 38 may be in the same housing, or may be configured to be provided with a connector and connected by the coaxial cable 37 as described above.

  5 and 6 are diagrams showing a specific configuration example of the digital transmission line 34. FIG. The digital transmission line 34 may be any one that transmits the digital signal converted by the signal conversion unit 33 without delay and without interruption. For example, a dedicated two-wire or three-wire signal line may be used. Etc. are available. Alternatively, a serial communication standard such as RS485 may be used.

  However, recently, a LAN for a computer network is often laid in the building 35. By using this, it is easy and inexpensive to install a digital wiring for transmitting GPS signals. A system can be constructed. Therefore, the example of FIG. 5 uses a wired LAN 34a, and the example of FIG. 6 uses a wireless LAN 34b.

  In addition, when the wireless LAN 34b is used, the signal restoration unit 36 and the GPS antenna 38 can be easily installed in each room. In other words, the LAN terminal is often installed on the wall or floor, and the GPS antenna 38 may be installed on the ceiling in order to avoid obstacles to the GPS receiver 40 held by a person in the room. desirable. Therefore, by using the wireless LAN 34b, even if the access point 34c is installed at an arbitrary place such as the wall surface or floor surface, the signal restoration unit 36c having a wireless communication function with the access point 34c is close to the GPS antenna 38. Can be installed on the ceiling.

  Furthermore, when the access point 34c is installed on the roof of the building 35, the signal conversion unit 33c that digitally converts the signal received by the GPS antenna 32 also has a wireless communication function. Only the power supply line needs to be laid on the converter 33c. As the digital transmission line 34, a power line may be used as long as it can transmit a digital signal in the frequency band and a failure such as a transformer is taken into consideration. When configured in this manner, in the digital transmission path 34, the signals from the respective GPS satellites 31 are delayed by the same amount, so that the positioning result is not affected.

  Here, when the signal digitized by the analog / digital conversion unit 42 is converted to analog by the digital / analog conversion unit 52 and restored, the conversion clock speed in the analog / digital conversion unit 42 and the digital / analog conversion unit 52 are restored. It is necessary to make the conversion clock speed in the same. When a dedicated line is used as the transmission line, it can be easily realized by transferring the clock together with the data.

  On the other hand, when the LAN or the like is used as a transmission path, after the data received by the LAN receiving unit 101 corresponding to the communication interface unit 51 is temporarily stored in the buffer 102, as shown in FIG. By inputting the data to the digital / analog conversion unit 52 and controlling the digital / analog conversion clock 103 so that the amount of data stored in the buffer 102 is constant, the restoration speed is converted into the conversion speed as described above. It can be made identical.

Normally, a GPS receiver used for consumer use uses a TCXO (temperature compensated crystal oscillator) with an accuracy of about several ppm (10 ⁻⁶ ). In order to cope with the influence of Doppler generated by the above, the operation is performed following the change in the frequency width of about several tens of kHz. Therefore, the accuracy of the clock 103 used in the digital / analog conversion unit 52 may be about 10 ⁻⁷ or less, and a general VCTCXO (voltage controlled temperature compensated crystal oscillator) or VCOCXO (voltage controlled oven crystal oscillator) ) Etc. can be used. These voltage-controlled crystal oscillators may be controlled so as to suppress fluctuations within a few Hz to a few hundred Hz by the clock control mechanism using the buffer 102 described above. Note that the clock 103 of the digital / analog conversion unit 52 may be shared with the clock of the up-conversion unit 53.

  Thus, when retransmitting the positioning GPS signal, the coaxial cable is connected only between the GPS antennas 32 and 38 and the signal conversion unit 33 or the signal restoration unit 36 provided in the vicinity thereof. The re-transmission apparatus can be realized that is low in cost and easy to change.

  In addition, the digital transmission path 34 does not transmit a signal obtained by directly converting a signal with a high carrier frequency from a GPS satellite, but the carrier frequency does not impair the baseband component by the down-conversion 41 of the signal conversion unit 33. Once the down-conversion and the up-conversion unit 53 of the signal restoration unit 36 restore the high carrier frequency from the original GPS satellite, the down-conversion unit 41 and the up-conversion unit 53 are necessary. The bit rate of the signal transmitted through the line 34 can be kept low, and low-priced digital transmission lines 34, analog / digital conversion units 42 and digital / analog conversion units 52 can be used, and the total cost can be reduced. Can be suppressed.

[Embodiment 2]
FIG. 7 is a diagram showing a schematic configuration of a positioning signal retransmission apparatus according to another embodiment of the present invention, and FIG. 8 is a functional block diagram thereof. 7 and FIG. 8 are similar to the configurations of FIG. 1 and FIG. 2 described above, and corresponding portions are denoted by the same reference numerals and description thereof is omitted. It should be noted that in the present embodiment, the GPS signal restored in one signal restoration unit 36 is separated via the distributor 61 into separate rooms 62-1, 62-2,. When generically referred to, it is configured to be sent to GPS antennas 38-1, 38-2,... (Shown by reference numeral 38 hereinafter). It is that you are. As a result, the GPS signal reception area can be easily expanded to a plurality of rooms 62 in the building 35.

  In this case, although the distributor 61 is interposed in the coaxial cable 37 from the signal restoration unit 36, if the number of the rooms 62 is simply distributed, the design is easy, and particularly the adjacent rooms as described above. If it is between 62, the condition of each room 62 is substantially equal, and complicated calculation of gain is not necessary. In addition, when there is a large difference in the distance from the distributor 61 to the GPS antenna 38 between the rooms 62 or in response to the difference in the size of the room 62, the radiation intensity from the GPS antenna 38 has a difference. For example, an attenuator may be appropriately provided on a coaxial cable to a GPS antenna close to the distributor 61 or a GPS antenna provided in a narrow room.

[Embodiment 3]
FIG. 9 is a diagram showing a schematic configuration of a positioning signal retransmission apparatus according to still another embodiment of the present invention, and FIG. 10 is a functional block diagram thereof. These configurations in FIGS. 9 and 10 are similar to the configurations in FIGS. 7 and 8 described above. It should be noted that in the present embodiment, the GPS antennas 32-1, 32-2,... That receive signals from the GPS satellite 31 (hereinafter collectively referred to as reference numeral 32) A plurality of units are installed on the roof so as to be spaced apart from each other, and the corresponding signal conversion units 33-1, 33-2,... Is connected to the wired LAN 34a in common. And the signal restoration part installed in each room 62-11, 62-12, ..., 62-21, 62-22, ... (when naming generically, it shows with the referential mark 62 below). 36-11, 36-12,..., 36-21, 36-22,... (Generally indicated by reference numeral 36 below) are GPS antennas 38-11, 38-12 that make a pair. ,..., 38-21, 38-22,... (Generally referred to as reference numeral 38 below) and upper and lower rooms (for example, 62-11, 62-21, 62-31) It is to retransmit the received signal at the corresponding GPS antenna (for example, 38-11) in the same system.

  Each signal conversion unit 33 has the same configuration as that of FIG. 2 described above, and each signal restoration unit 36 has the same configuration as that of FIG. 2 described above. In FIG. Yes. In the retransmission apparatus configured as described above, for example, a signal received by the GPS antenna 32-1 is converted into a digital signal by the signal conversion unit 33-1, and each signal restoration unit of the same system is transmitted via the wired LAN 34a. 36-11, 36-21, 36-31 are addressed and the same data is transmitted in common, and from the GPS antennas 38-11, 38-21, 38-31 to the rooms 62-11, 62-21, 62-31. Radiated in. Alternatively, for example, IDs “A”, “B”, “C”,... Are added to the signals transmitted by the signal conversion units 33 and transmitted, and the signal restoration unit 36 installed in each room Only a signal to which a corresponding system ID is assigned may be selected and received.

  With this configuration, the positioning result by the GPS receiver 40 is the position of the GPS antenna (32-1 in FIG. 9) immediately above the room (62-21 in FIG. 9). Even if it is inside, the position accuracy can be increased by the number of GPS antennas 32, which is suitable for a relatively large building. Further, since each signal conversion unit 33 and each signal restoration unit 36 share the wired LAN 34a as a digital transmission line, a system can be constructed at low cost. In addition, the number of systems can be increased or decreased as necessary, and the system can be flexibly constructed.

  Moreover, the structure shown in these FIG. 9 and FIG. 10 can be particularly suitably implemented in an elevator or an underground mall. In other words, since the latitude and longitude of the elevator are constant and only the altitude changes, it is possible to know the exact position on the plane by installing the GPS antenna 32 immediately above the elevator, and also in emergency situations such as confinement Location information is useful at the time of occurrence, and the present invention is particularly suitable. Furthermore, since the underground shopping street is generally spread over a considerably wide area, positioning with high accuracy can be performed by arranging a large number of receiving GPS antennas 32 and corresponding GPS antennas 38 for retransmission. The user can be accurately guided in the basement with a small number of landmarks.

  Moreover, the structure shown in the said FIG. 9 and FIG. 10 may be implemented in a train. The train is originally shielded by a metal vehicle body, and there are many people who are easily affected by high-frequency signals such as GPS.

[Embodiment 4]
FIG. 11 is a diagram showing a schematic configuration of a positioning signal retransmission apparatus according to another embodiment of the present invention. This embodiment is similar to the above-described embodiments. In each of the above-described embodiments, the signal restoration unit 36 retransmits a signal that has been up-converted to 1.57542 GHz, which is the same as the GPS signal, but it should be noted that in this embodiment, signal restoration is performed. The unit 36 ′ is to up-convert to a frequency different from the signal received by the GPS antenna 32 and retransmit from the GPS antenna 38.

  In this case, since it is impossible for the terminal side to perform positioning using a general-purpose GPS receiver that is generally used, a GPS receiver 70 that can receive at another RF frequency must be prepared. However, for example, when the signal restoration unit 36 ′ is installed in a place where a signal from the actual GPS satellite 31 can be received, there is an advantage that interference can be eliminated.

  Furthermore, as shown in FIG. 12, the GPS receiver 70 receives a normal GPS antenna 71 and an RF unit 72 that receive RF of 1.57542 GHz, and another GPS antenna 73 and RF that receive this particular frequency. It is also possible to provide the portion 74. The received signals amplified by the RF units 72 and 74 are input to the baseband chip 75 to extract baseband components such as the CA code, and input to the CPU 76 for use in positioning calculation.

  The GPS receiver 70 configured as described above performs positioning using the signal received by the 1.57542 GHz-compatible GPS antenna 71 and the RF unit 72 in a place where the signal from the actual GPS satellite 31 can be received and measured. Otherwise, positioning is performed using signals received by another GPS antenna 73 and an RF unit 74 that receive other frequencies. As a result, as shown in FIG. 11, even if the GPS receiver 70 is placed in an area where the signal from the actual GPS satellite 31 can be received and the signal from the signal restoration unit 36 'can also be received, It is possible to receive and measure without having to.

  As yet another embodiment, there is provided a function of explicitly outputting which signal the terminal incorporating the GPS receiver 70 having the two RF units 72 and 74 has measured. You may do it. With this configuration, for example, when the location of the person who owns the terminal is retrieved from a management center not shown, the terminal is determined by a signal from the actual GPS satellite 31 or a signal restoration unit. It is possible to inform the management center whether positioning has been performed with a signal from 36 '. In the management center, if the positioning is based on the actual GPS satellite 31, the corresponding person is outdoors, and the accuracy of the positioning data is high, and if the positioning is based on the signal from the signal restoration unit 36 ′, the corresponding person Is indoors, and it can be known that the positioning result includes a certain amount of error (because it may be displaced from the position of the GPS antenna 32). This makes it possible to take appropriate measures when searching for the person concerned.

It is a figure which shows schematic structure of the resending apparatus of the signal for positioning which concerns on one Embodiment of this invention. FIG. 2 is a functional block diagram of a signal conversion unit and a signal restoration unit in the positioning signal retransmission apparatus shown in FIG. 1. FIG. 3 is a block diagram illustrating a specific configuration of a down-conversion unit in the signal conversion unit illustrated in FIG. 2. FIG. 3 is a block diagram illustrating a specific configuration of an up-conversion unit in the signal restoration unit illustrated in FIG. 2. It is a figure which shows the specific structural example of the digital transmission path in the retransmission apparatus of the signal for positioning shown in FIG. It is a figure which shows the other specific example of a structure of the digital transmission path in the retransmission apparatus of the signal for positioning shown in FIG. It is a figure which shows schematic structure of the resending apparatus of the signal for positioning which concerns on the other embodiment of this invention. It is a functional block diagram of the retransmission apparatus shown in FIG. It is a figure which shows schematic structure of the resending apparatus of the signal for positioning which concerns on the further another form of implementation of this invention. FIG. 10 is a functional block diagram of the retransmission apparatus illustrated in FIG. 9. It is a figure which shows schematic structure of the resending apparatus of the signal for positioning which concerns on the other embodiment of this invention. FIG. 10 is a functional block diagram of a GPS receiver adapted to the retransmission apparatus shown in FIG. 9. It is a figure for demonstrating a typical prior art. It is a figure for demonstrating another prior art. It is a functional block diagram which shows the structure for the digital / analog conversion in the signal decompression | restoration part in the case of using LAN as a transmission line.

Explanation of symbols

31 GPS satellite 32; 32-1, 32-2 ... GPS antenna 33; 33c; 33-1, 33-2, ... Signal converter 34 Digital transmission line 34a Wired LAN
34b Wireless LAN
34c Access point 35 Building 36; 36c; 36 'Signal restoration unit 36-11, 36-12, ..., 36-21, 36-22, ... Signal restoration unit 37 Coaxial cable 38; 38-1, 38 -2, ... GPS antenna 38-11, 38-12, ..., 38-21, 38-22, ... GPS antenna 41 Down-conversion unit 42 Analog / digital conversion unit 43, 51 Communication interface unit 44, 47; 54, 57 Mixer 45, 48; 55, 58 Local oscillator 46, 49; 56, 59 Intermediate frequency filter 52 Digital / analog converter 53 Up-converter 40, 70 GPS receiver 61 Distributor 62; 62 -1, 62-2, ... Rooms 62-11, 62-12, ..., 62-21, 62-22, ... Rooms 71, 73 GPS antenna 72, 74 RF unit 75 baseband chip 76 CPU
101 LAN receiver 102 buffer 103 clock

Claims (5)

A mobile terminal having a positioning function even in an environment where it is difficult to receive the positioning signal by receiving the positioning signal with the first antenna and retransmitting the positioning signal through the transmission path from the second antenna. In the positioning signal re-transmission device that enables positioning by
The transmission path comprises a general-purpose digital transmission path,
A signal converter for converting the received signal of the first antenna into a digital signal and transmitting the digital signal to the digital transmission path;
A re-transmission of positioning signal, comprising: a signal restoring unit that receives a digital signal from the digital transmission path, restores the positioning signal from the digital signal, and radiates the signal from the second antenna. apparatus. The positioning signal is a signal from a GPS satellite,
The signal conversion unit includes an analog / digital conversion unit that converts a reception signal of the first antenna into a digital signal, and a communication interface unit that transmits the converted digital signal to the digital transmission path. A down-converting unit for down-converting the received signal of the antenna to a predetermined frequency band and then supplying the signal to the analog / digital conversion unit,
The signal restoration unit includes a communication interface unit that receives a digital signal from the digital transmission path and a digital / analog conversion unit that converts the received digital signal into an analog signal, and the restored analog signal is measured by the positioning method. 2. The positioning signal retransmission apparatus according to claim 1, further comprising an up-conversion unit configured to up-convert the signal to the same frequency as that of the signal for use and to supply the second antenna.   A plurality of the first antennas are provided, and the signal conversion unit, the signal restoration unit, and the second antenna are provided in a plurality of systems corresponding to the first antennas. 3. The positioning signal retransmission apparatus according to claim 1, wherein the positioning signal retransmission apparatus is connected to a transmission line.   The positioning signal retransmission apparatus according to claim 1, wherein the second antenna is installed in an elevator.   4. The positioning signal retransmission apparatus according to claim 3, wherein the second antenna is installed in an underground shopping center.

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