Positional information transmitter

Technical Field [0001] The present invention relates to the technique of providing position information. More specifically, the present invention relates to a technique for providing position information even in an environment beyond the range of the signal transmitted from a satellite emitting a positioning signal.

Background Art [0002] The GPS (Global Positioning System) is known as the conventional positioning system. A satellite (hereinafter referred to as "GPS satellite") transmitting the signal used in the GPS system (hereinafter referred to as "GPS signal") flies about 20,000 km above the Earth's surface. By receiving and demodulating the signal emitted by the GPS satellite, the user can measure the distance between this GPS satellite and the user. Therefore, if there are no obstacles between the Earth's surface and the GPS satellite, positioning using the signal emitted by the GPS satellite is possible. However, consider using GPS in an urban area. There can often be a case where the signal emitted by a GPS satellite, stopped by a large number of tall buildings, cannot be received by a device providing information about the user's position. In addition, building diffraction or reflection may cause a distance measurement error using this signal and as a result positioning accuracy is often reduced.

[0003] Although the technique of receiving a weak GPS signal in a room that has passed through a wall or roof is known, the reception is unstable and the positioning accuracy is low.

[0004] Accordingly, positioning using a GPS system has been described by way of examples. However, the phenomenon described above is generally common to positioning systems using satellites. Satellite positioning systems are not limited to the GPS system and may include systems such as the GLONASS (GLOba! Navigation Satellite System) of the Russian Federation and European Galileo.

[0005] A technique related to the provision of position information has been disclosed, for example, in Japanese Patent Laying-Open No. 2006-67086 (Patent document 1). Patent Document 1: Japanese Patent Laying-Open No. 2006-67086 [0006] Document US 5,708,440 A relates to a navigation receiver that is adapted to work with signals received from navigation satellites and from pseudosatellites (ang. pseudolite) located in fixed locations, in a localized area inside the building or outside, in the area with a obstructed line of direct visibility with satellites. If no satellite signals are available, a number of pseudosatellites are required to determine the position of this navigation receiver, each pseudosatellite emulating the function and radio transmission of a conventional GPS satellite transmitter and providing a fixed pseudosatellite position. Such a navigation receiver must receive modulated carrier signals from at least four pseudosatellites arranged in a manner suitable for three-dimensional triangulation.

[0007] This document also presents a mobile receiver assembly that includes a local area navigation receiver and a conventional GPS navigation receiver to provide navigation function also in an (partly) inaccessible area for transmission from orbiting GPS satellites, with all or part pseudosatellites missing elements required to calculate the position by means of three-dimensional triangulation.

Disclosure of the Invention

Problems Solved by the Invention [0008] In the technique disclosed in Japanese Patent Laying-Open No. 2006-67086, the reader or writer is unique to the system for providing position information and lacks versatility. To prevent interference, it is necessary to limit the transmission, and therefore the area in which position information can be received is limited, and it is difficult to receive position information continuously. In addition, a large number of transmitters are required to cover a larger area.

[0009] Furthermore, with respect to the acquisition or reporting of position information, the location of the signal transmission source is possible if the telephone connection is made from a landline telephone, as the location of the landline telephone is known in advance. However, the widespread use of mobile telephones makes mobile communication more and more popular and reporting caller position information is becoming more and more difficult, unlike the landline phone case. On the other hand, legal solutions for including position information in the call were considered for emergency calls from a mobile phone.

[0010] A conventional mobile telephone with positioning function receives position information where satellite signal reception is possible, and therefore it is possible to report the position of a mobile telephone. However, where radio reception is not possible, such as in underground passages or indoors, position information cannot be obtained using conventional positioning techniques.

[0011] In light of the foregoing, one may consider a technique in which a number of transmitters, arranged to emit GPS-like signals, are positioned in the rooms to determine position based on a GPS-like trilateration principle. However, this approach requires that the transmitters be synchronized over time, which increases the cost of the transmitters.

[0012] In addition, indoor reflections and the like result in complicated radio wave propagation, which easily leads to errors of 10m.

[0013] The present invention has been made to solve the problem described above and its purpose is to provide a position information system that would provide position information without loss of accuracy even at a location out of range of the radio wave from a satellite emitting a positioning signal.

[0014] Another objective is to provide a position information system that provides position information based on a signal that does not require synchronization in time with a satellite emitting a positioning signal.

[0015] Another object is to provide an information providing device that can provide position information without loss of accuracy even in a location out of range of the radio wave from a satellite emitting a positioning signal.

[0016] Another object is to provide an information providing device that can provide position information based on a signal that does not require time synchronization with a satellite emitting a positioning signal.

[0017] Another object is to provide a transmitter that can transmit a signal providing position information without loss of accuracy even at a location out of range of the radio wave from the satellite emitting the positioning signal.

[0018] Another object is to provide a transmitter that can transmit a signal providing position information based on a signal that does not require time synchronization with a satellite emitting a positioning signal.

Means for Solving the Problems Said [0019] To solve the problems described above, according to an aspect, the present invention provides a position information system for providing position information. This system includes a transmitter. The transmitter includes a storage module that stores positioning data for indicating the location where the transmitter is installed, a generating module that generates the first positioning signal with positioning data in the form of a spread spectrum signal, and a transmission module that transmits this signal with spread spectrum. The position information system further includes a position information device. The position information device includes a receiving module that receives a spread spectrum signal, a storage module that stores the code pattern for the first positioning signal, a specifying module that, based on the code pattern stored in the storage module, indicates the code pattern that corresponds to the signal with spread spectrum received by the receiving module, a determining module that determines whether or not the first positioning signal has been received, based on the signal demodulated using the code pattern indicated by the specifying module, the acquisition module that obtains positioning data from the demodulated signal when the first positioning signal was received, and an output module that displays the positioning data acquired by the acquisition module. [0020] Preferably, the first positioning signal has the same format as the second positioning signal emitted by the positioning satellite transmitting the positioning data and instead of the navigation message contained in the second positioning signal. In addition, the position information device stores, in a storage module, a code pattern of each of the second positioning signals. The position information storage device further includes a computing unit calculating the position of the position information providing device based on each beacon message when a number of second positioning signals are received.

[0021] Preferably, the encoded positioning signal has a center frequency of 1574.42 MHz. The positioning signal scattering frequency is 1.023 MHz.

[0022] According to another aspect, the present invention provides a position information providing device for providing position information. This device includes a receiving module that receives a spread spectrum signal and a storage module that stores the code pattern for the first positioning signal. The first positioning signal is emitted from a transmitter installed in a predetermined location and contains positioning data to indicate that location. This device includes a specification module to indicate, based on the code pattern stored in the storage module, a code pattern corresponding to the spread spectrum signal received by the receiving module, a determining module which, based on a signal demodulated using the code pattern indicated by the specification module, determines whether the first positioning signal was received, the acquiring module, which, when the first positioning signal was received, acquires positioning data from the deceived signal and output module displaying the positioning data obtained by the acquisition module. Preferably, the first positioning signal has the same format as the second positioning signal, emitted by the positioning satellite and contains the positioning data instead of the navigation message contained in the second positioning signal. In addition, the position information device stores, in a storage module, a code pattern for each of the second positioning signals transmitted from a number of satellites. The code pattern is different for each satellite. The position information providing device further includes a computing unit calculating the position of the position information providing device based on each beacon message when a number of second positioning signals are received.

[0024] Preferably, the receiving module receives each of the first positioning signals emitted from the transmitters installed in a number of predetermined locations. The position information device further includes a detection module that detects the strength of the signal received by the receiving module. The acquiring module indicates among the first positioning signals the first positioning signal with the highest intensity and acquires the positioning data contained in this indicated first positioning signal.

[0025] Preferably, the positioning data includes information representing the location where the transmitter is installed. The output module contains a display module that based on this information displays the location where the transmitter is installed.

[0026] Preferably, the positioning data includes identification data for identifying the transmitter. The device includes a transmitting module which, when the first positioning signal is received, transmits this identification data and a request for transmission of transmitter position information via a communication line to the server that provides position information in response to an external request, position information and identification data is stored in conjunction with each other on the server. The device further includes an input module that receives position information as input from the server in response to a request for transmission over a communication line. The output module includes a display module for displaying position information.

[0027] Preferably, the position information providing device comprises a mobile telephone, a portable information terminal, a portable positioning device or a positioning system installed in the vehicle.

[0028] Preferably the transmitter is connected to a clock device displaying time information at the output. The positioning signal at the transmitter output contains time data representing the time synchronized with the time of the clock device. The position information device further includes a clock module that sets time and displays time information on the output, and a calibration module that calibrates the clock module time based on the time data contained in the positioning signal received by the receiving module.

[0029] Preferably, the position information providing device further comprises a storage module that stores attribute data representing the attributes of the position information providing device, the requesting module transmitting the information distribution request according to the attribute data to the information providing device adapted to transmit information according to the given attribute data in the request, and the input module, receiving, as input, information broadcast by a device providing information based on a distribution request. The output module includes a display module for displaying this information.

[0030] According to another aspect, the transmitter comprises a storage module that stores positioning data for determining the location where the transmitter is installed, a generator module generating a signal with positioning data in the form of a spread spectrum signal and a transmission module that transmits this signal with a spread spectrum. .

[0031] Preferably, the generating module generates a signal of the same format as the positioning signal emitted by the satellite transmitting the positioning signal as a spread spectrum signal.

Effects of the Invention [0032] The position information system according to the present invention is adapted to provide position information using a signal not synchronized with the satellite.

Description of the figures [0033]

Fig. 1 illustrates the configuration of the position information system 10 according to the first embodiment of the present invention.

Fig. 2 is a block diagram showing the hardware configuration of the transmitter for indoor use 200-1.

Fig. 3 is a conceptual diagram showing how to store data in EEPROM 240 memory provided in a transmitter for indoor operation 200-1.

Fig. 4 is a block diagram illustrating the hardware configuration of the device providing position information 100-1.

Fig. 5 shows the positioning signals transmitted from the transmitter.

Fig. 6 is a flowchart showing the procedure performed by a device providing position information 100.

Fig. 7 shows an image on the display 440 of the device providing position information 100.

Fig. 8 is (first) a diagram showing the signal structure according to another aspect of the first embodiment of the present invention.

Fig. 9 is a (second) diagram illustrating the signal structure according to another aspect of the first embodiment of the present invention.

Fig. 10 is a block diagram illustrating the configuration of a device providing position information 1000 according to a modification of the first embodiment of the present invention.

Fig. 11 illustrates a situation in which a device providing position information according to a modification of the first embodiment of the present invention is used.

Fig. 12 illustrates how to use the position information device according to the second embodiment of the present invention.

Fig. 13 is a block diagram illustrating the hardware configuration of mobile telephone 1200 according to the third embodiment of the present invention.

Fig. 14 is a block diagram illustrating the hardware configuration of a server providing information 1230 according to a third embodiment of the present invention.

Fig. 15 is a conceptual diagram illustrating how to store data on a hard disk

1450 on the server providing 1230 information.

Description of labels [0034} 10 system providing position information, 110, 111, 112 sateiita GPS, 120, 121, 122 transmitter, 100-1, 100-2, 100-3, 100-4, 1000, 1160, 1170 device providing position information, 130 building, 200-1, 200-2, 200-3, 1110, 1120, 1130 1210 transmitter for indoor use, 1010, 1308 antenna, 1140, 1150 area, 1220 Internet network, 1382 memory card, 1462 CD-ROM.

Most Preferred Embodiments of the Invention [0035] Embodiments of the present invention are described below with reference to the figures. In the following description, the same ingredients are labeled with the same labels. Their names and functions are also the same. Therefore, their detailed description will not be repeated.

<First embodiment of the invention>

[0036] With reference to Fig. 1, a system providing position information 10 according to a first embodiment of the present invention will be described. Fig. 1 shows the configuration of the system providing position information 10. The system providing position information 10 includes GPS satellites Global Positioning System) 110, 111, 112 and 113, flying at an altitude of 20,000 meters above the Earth's surface, transmitting positioning signals (hereinafter referred to as positioning signals) and devices providing position information 100-1 to 100-4, working as devices for providing position information. Devices providing position information 100-1 to 100-4 will generally be referred to as equipment providing position information 100. The position information device 100 is, for example, a terminal having a conventional positioning device, such as a mobile telephone, car navigation system or other mobile positioning device, [0037] The positioning signal here is the so-called spread spectrum signal and, for example, is it's the so-called GPS signal. However, this signal is not limited to GPS. To simplify the description, the positioning system will be described using GPS as an example. The present invention is also applicable to other satellite positioning systems (such as Galileo and GLONASS). [0038] The central frequency of the positioning signal is, for example, 1547.42 MHz. The positioning signal scattering frequency is, for example, 1.023 MHz. The positioning signal frequency here becomes the same as the C / A (Coarse and Access) signal in the L1 band of the current GPS system. This means that an existing positioning signal receiving circuit (such as a GPS receiving signal circuit) can be used and therefore a device providing positioning information 100 can receive a positioning signal without adding any new circuits.

[0039] The positioning signal can be modulated with a 1.023 MHz square wave. In this case, if the data channel of the modulated signal is the same as the planned positioning signal for a new transmission in the L1 band, the user may receive this positioning signal using a receiver that can receive and process the new GPS signal. The frequency of the square wave may be different from 1.023 MHz. The modulation frequency is determined based on a spectral separation compromise to avoid interference of the decoded signal with the current C / A signal and / or other signal.

[0040] The GPS 110 satellite has a transmitter 120 mounted thereon for transmitting the positioning signal. Sateiity GPS 111, 112 and 113 have similar, respectively mounted transmitters 121, 122 and 123. Devices providing position information 100-2, 100-3 and 100-4, with similar functions as the device providing information about position 100-1, are useful in places where radio reception is difficult, as in building 130. On the ground floor ceiling of building 130, a transmitter is mounted for work in interiors 200-1. The device providing position information 100-4 receives the positioning signal emitted by the transmitter for indoor use 200-1. Similarly, transmitters for indoor operation 200-2 and 200-3 are attached to the ceilings of the first and second floors 130, respectively. The time of each of the transmitters to work indoors 200-1, 200-2 and 200-3 (here referred to as "earth time") can be independent of the time of GPS 110, 111, 112 and 113 (hereinafter "satellite time") and does not need to be synchronized. It is desirable that the sites be synchronized in time with each other.

[0041] The spread spectrum signal emitted from each transmitter as a positioning signal is generated by modulating the navigation message with a pseudo-random noise code (PRN). The navigation message contains time data, orbital information, almanacs and ionospheric correction data. Each transmitter 120 further has data (PRN-ID) to identify the transmitter 120 itself or to identify the site on which the transmitter 120 is mounted.

[0042] The device providing position information 100 has data for generating each PRN code and a code generator. When receiving the positioning signal, the device providing position information 100 performs the demodulation process, which will be described later, using the PRN code pattern assigned to each of the satellites, so that it can determine from which satellite the received signal is emitted. In addition, the new GPS signal contains in the data the PRN-ID and diate ID, it is possible to prevent the acquisition and tracking of the signal using an incorrect code pattern, which is likely at a low reception level.

[0043] The schematic configuration of the transmitter mounted on the GPS satellite is as follows. Each of the transmitters 120, 121 and 122 includes an atomic clock, a data storage device, an oscillator circuit, a processing circuit for positioning signal generation, a coding circuit for coding with spectrum spreading of the signal generated by the processing circuit, and a transmitting antenna. The storage device stores a navigational message containing ephemeris, the almanac of each satellite, ionospheric correction data and the like, as well as the PRN-ID.

[0044] The processing circuit generates a message to be sent using the time information from the atomic clock and various data stored in the storage device.

[0045] It should be noted that the code pattern for the PRN code for spectrum spreading coding is for each transmitter 120 defined in advance, the code pattern for each transmitter (i.e. GPS satellite) is different. The coding circuit spreads the spectrum of the message using the PRN code. The transmitter 120 transmits the encoded signal to high frequencies and emits the received signal into space through the transmitting antenna.

[0046] As described above, the transmitter 120 emits a spread spectrum signal without causing harmful interference with other transmitters. Not causing "harmful interference" can be ensured here by limiting the output signal level to prevent any interference. Alternatively, this can be achieved by spectrum spreading. The signal is transmitted using, for example, a carrier wave called the L1 band. Transmitters 120, 121 and 122 emit positioning signals at the same frequency, for example, in accordance with a distributed spectrum communication system. Therefore, when positioning signals transmitted from individual satellites are received by a device providing position information 100-1, the corresponding positioning signals can be received without crosstalk. As for the positioning signals from transmitters for indoor operation on the Earth's surface, similar to signals transmitted from satellites, positioning signals from a number of transmitters for indoor operation can be received without crosstalk.

[0047] The transmitter for indoor operation 200-1 will be described with reference to Fig. 2. Fig. 2 is a block diagram showing the hardware configuration of the transmitter for indoor operation 200-1. [0048] The indoor transmitter 200-1 includes a digital processing block 210, EEPROM ( Electricaify Erasable and Programmable Read Only Memory) 240 electrically connected to the 210 digital processing block, UART 250 electrically connected to the 210 digital processing block, digital input / output interface 260 electrically connected to the 210 digital processing block, 280 clock electrically connected to the digital processing block 210, an analog processing block 290 electrically connected to a digital processing block 210, an antenna 292 electrically connected to an analog processing block 290 and a power supply 294. The digital processing block 210 includes a Central Processing Unit (CPU) 220 and RAM (Random Access Memory) 230.

[0049] The EEPROM 240 memory stores a program for execution by the CPU 220, data representing the location where the transmitter is installed for indoor operation 200-1, and so on. After starting the transmitter for indoor operation 200-1, the program or data is read from the EEPROM 240 memory and transferred to the RAM 230 memory. The EEPROM 240 memory can also store input data from the outside of the transmitter for indoor operation 200-1. The storage device for storing the program or data is not limited to the EEPROM 240 memory. A storage device adapted at least to non-volatile storage can be used. As will be described later, when data is displayed externally, any storage device that allows data to be saved can be used. The data structure of EEPROM 240 will be described later.

[0050] Digital processing block 210 generates data as a signal source for transmission by the transmitter for indoor operation 200-1 in the form of a positioning signal. The digital processing biok 210 sends the generated data as a bit stream to the analog processing bioc 290.

[0051] Clock 280 provides to the digital processing block 210 a clock signal determining the operation of the CPU 220 or a clock signal for carrier generation.

[0052] The digital input / output interface 260 is adapted to monitor the internal state (e.g., the "PLL Cntrl" signal) of the transmitter. Alternatively, the digital input / output interface 260 can receive input from the outside in the form of a pseudo-noise code pattern for the spreading modulation of the emitted signal from the transmitter for indoor operation 200-1 or input data specifying the outgoing transmission. In addition, it can receive other input data for emission from the transmitter for indoor operation 2001. These other data include text data representing the location where the transmitter for indoor operation 200-1 is installed. If the 200-1 indoor transmitter is installed in a commercial establishment, such as a department store, advertising data may be entered into the 2001 indoor transmitter as other data.

[0053] After entering the transmitter for indoor operation 200-1, the spreading code pattern is stored in the predetermined EEPROM 240 memory area, Then the stored PRN-ID is included in the positioning signal. Other data is also saved, depending on the data type, in the previously provided EEPROM 240 memory areas.

[0054] The UART 250 system is used to adjust the transmitter for indoor operation 200-1. The external clock 270 is used to adjust the transmitter for indoor operation 200-1, like the UART 250. For example, the external clock 270 is used to obtain the frequency of the power line (not shown) and calibrate the frequency of the positioning signal.

[0055] Analog processing block 290 modulates a carrier wave at 1.57542 GHz, using a bit stream from the output of digital processing block 210 to generate a transmission signal, and feeds it to antenna 292. This signal is transmitted from antenna 292. In this way, the transmitter indoor operation, a signal is emitted with the same configuration as the positioning signal. The content of this signal is not exactly the same as the content of the positioning signal emitted from the satellite. An example of the configuration of the signal emitted from the transmitter for indoor operation 200-1 will be described later (Fig. 5).

[0056] Power supply 294 provides electrical power to individual transmitter components for indoor operation 200-1. The power supply 294 can be built into the transmitter for indoor operation 200-1 as shown in Fig. 2 and or the power supply can be supplied from outside.

[0057] In the above description, the CPU 220 is used as an arithmetic processing module for carrying out the process in the digital processing module 210. Another arithmetic processing module may be used. Furthermore, since the operations carried out by the transmitter for indoor operation 200-1 are not complex, the digital processing block 210 can be implemented by means of electrical systems adapted to implement various processes, instead of using the CPU 220.

[0058] Furthermore, although in Fig.2 the clock signal (Cik) is provided from digital processing block 210 to analog processing block 290, it can be supplied directly from clock 280 to analog processing block 290.

[0059] In the present embodiment of the invention, the digital processing block 210 and the analog processing module 290 are shown separately for clearer description. Physically, these blocks can be mounted in one integrated circuit.

[0060] The data structure of the transmitter for indoor operation 200-1 will be described with reference to Fig. 3. Fig. 3 is a conceptual illustration showing how to store data in EEPROM 240 memory provided in a transmitter for indoor operation 200-1. The EEPROM 240 has areas 310 to 340 for storing data.

[0061] Area 300 stores the transmitter identifier (ID) as a number to identify that transmitter. For example, the transmitter identifier is numeric and / or alphabetic sequences or other connections, stored in a non-volatile way when the transmitter is manufactured, the PRN-ID of the spreading code assigned to the transmitter is stored in area 310. The name of the transmitter is stored as text data in the area 320.

[0062] The spreading code pattern assigned to the transmitter is stored in area 330. The spreading code pattern is selected from a finite number of code patterns previously allocated to the system providing position information according to an embodiment of the present invention and this is a different code pattern from the spreading code patterns assigned to each of the satellites. In addition, as described above, the spreading code pattern is interchangeable with another code pattern introduced via digital input / output interface 260.

[0063] The number of spread code patterns allocated to the subject position information system is finite. The number of transmitters for indoor use varies, depending on the size of the transmitter installation site or the structure of the installation site (for example, the number of floors in a building). It is possible to use more transmitters for indoor use than (number of code patterns. Therefore, a number of transmitters may occur with the same spreading code pattern. In this case, the place of installation of transmitters with the same code pattern can be determined taking into account the signal output power. This prevents the simultaneous reception of a number of positioning signals using the same spreading code pattern by one device providing positioning information.

[0064] Positioning data for indicating the location where the transmitter for indoor operation 200-1 is installed is stored in area 340. For example, positioning data is represented as a combination of latitude, longitude and altitude. In area 320, in addition to or instead of positioning data, the address or building name may be stored. [0065] A device providing position information 100-1 will be described with reference to Fig. 4. Fig. 4 is a block diagram showing the hardware configuration of the device providing position information 100-1.

[0066] The device providing position information 100 includes an antenna 402, a radio head circuit (RF) 404 electrically connected to the antenna 402, a downward frequency conversion 406 electrically connected to the head circuit RF 404, an A / D converter ( analog to digital Analog to Digital) 408 electrically connected to a down-conversion 406, baseband processor 410 electrically connected to an A / D 408 converter, memory 420 electrically connected to a baseband processor 410, navigation processor 430 electrically connected to a baseband processor 410 and display 440 electrically connected to the 430 navigational processor. [0067] Memory 420 includes a number of areas for storing pseudo-noise code patterns as data for identifying each of the positioning signal emission sources. For example, in one aspect, using 48 code patterns, memory 420 includes areas 421-1 to 421-48, as shown in Fig. 4. According to another aspect, when more code patterns are used, more memory regions 420 are provided . On the other hand, it is also possible to use a smaller number of code patterns than the number of areas provided in memory 420.

[0068] Consider an example that uses 48 code patterns. If 24 satellites are used in the satellite positioning system, 24 identification data are stored in areas 421-1 to 421-36 to identify the respective satellites and 12 reserve data. For example, in the area 421-1, the pseudo-noise code pattern for the first satellite is stored. Tracking the signal and decoding the navigation message contained in this signal becomes possible by reading the code pattern from this area and performing the process of mutual correlation with the received signal. Although, as an example, a method is described herein in which a code pattern is stored and read, a method in which the code pattern is generated by the code pattern generator is also possible. For example, the code pattern generator is implemented by connecting two registers with feedback. The structure and operation of the code pattern generator are easily understood by a person skilled in the art. Therefore their detailed description will not be repeated here.

[0069] Similarly, pseudo-noise code patterns assigned to indoor transmitters emitting positioning signals are stored in areas 421-37 to 421-48. For example, the pseudo-noise code pattern assigned to the first transmitter for indoor use is stored in area 432-37. In the present embodiment of the invention, transmitters for indoor operation with 12 code patterns can be used. Indoor transmitters can be arranged in such a way that indoor transmitters with the same code pattern are not placed in the coverage area of ​​one device providing position information. Thanks to this arrangement, it becomes possible to install transmitters for indoor work in a number of more than 12 on one floor of building 130.

[0070] The baseband processor 410 includes a correlator module 412, receiving an input from the A / D converter 408, a control module 414, controlling the operation of the correlator module 412 and a determining module 416, determining the source of the positioning signal emission based on the output of control module 414 . The navigational processor 430 includes an outdoor positioning module 432 for measuring the position of the device providing position information 100 out based on the output of the determining module 416, as well as an indoor positioning module 434 for extracting information representing the position of the device providing position information 100 in the interior based on output of the determining module 416.

[0071] Antenna 402 can receive positioning signals emitted from GPS satellites 110, 111 and 112, respectively, as well as positioning signal emitted from the transmitter for indoor operation 200-1. In addition, when the device providing position information 100 is implemented as a mobile telephone, in addition to the signals mentioned above, the antenna 420 may transmit / receive signals for a cordless telephone or data for data transmission.

[0072] The RF head circuit 404 receives the signals received by the antenna 402 and performs a noise reduction or filtration process to issue output signals only in a predetermined band. The RF 404 head circuit output signal is fed to the downstream 406 frequency conversion system.

[0073] The down-conversion frequency 406 amplifies the output signal of the RF head circuit 404 and exposes it as an intermediate frequency signal. This signal is fed to the A / D 408 converter. The A / D 408 converter performs digital conversion of the input signal on the intermediate frequency into digital data. This digital data is fed to the baseband processor 410.

[0074] In the baseband processor 410, the correlator module 412 performs the correlation process between the received signal and the code pattern read by the control module 414 from the memory 420. For example, the correlator module 412 performs matching of two different code patterns for which the code phase differs by 1 bit , provided by control module 414, with digital data sent from the A / D 408 converter. Correlator module 412 tracks the positioning signal received by the device providing position information 100 using each of the code patterns and determines the code pattern whose sequence matches the positioning bit sequence of the signal. As a consequence, the code pattern for the pseudo-noise code is determined, and as a result, the device providing position information 100 can determine from which satellite or from which indoor transmitter the received positioning signal was transmitted. In addition, the device providing position information 100 has the ability to demodulate and decode messages using a specific code pattern.

In particular, the determining module 416 implements the determination as described above and, according to the result of the determination, passes data to the beacon processor 430. The determining module 416 determines whether the PRN-ID contained in the received positioning signal is the PRN-ID assigned to the transmitter other than the transmitter mounted on the GPS satellite.

[0076] An example will be described herein in which 24 GPS satellites are used in the positioning system. 36 pseudo-noise codes are used here, including the reserve codes. In this example, the identifiers PRN-01 to PRN-24 are used as numbers (PRN-ID) to identify the corresponding GPS satellites, and the identifiers PRN-25 to PRN-36 are used as numbers for identifying spare satellites. Spare satellite means a satellite launched in addition to the initially launched satellites. Such a satellite can in particular be launched in the event that a GPS satellite or transmitter, or a similar device mounted in the GPS system, fails.

[0077] Furthermore, it is assumed that 12 pseudo-noise code patterns are allocated to transmitters (such as an indoor transmitter 200-1 and the like) other than transmitters mounted on GPS satellites. Numbers different from PRN-IDs assigned to satellites, for example PRN-37 to PRN-48, are assigned to individual transmitters here. Thus, it follows that in this example there are 48 PRN-IDs. IDs PRN-37 ~ PRN-48 are assigned here to transmitters for indoor operation in accordance with the placement of transmitters for indoor use. Therefore, if the applied transmit powers are not high enough to cause interference from signals emitted by each of the transmitters for indoor operation, the same PRN-ID may be used for different transmitters for indoor operation. This arrangement allows the use of more transmitters than the number of PRN-IDs allocated to transmitters on the Earth's surface.

[0078] Thus, the determining module 416 refers to a pseudo-noise code pattern 422 stored in memory 420 to determine whether the code pattern obtained from the received positioning signal matches the code pattern assigned to the transmitter for indoor use. If these code patterns match, the determining module 416 states that the positioning signal has been emitted from the internal transmitter. Otherwise, the determining module 416 states that the signal was emitted from the GPS satellite and determines, with reference to the code patterns stored in memory 402, to which GPS satellite the assigned code pattern has been allocated. Although an example has been described in which the code pattern is used for the determination, the determination can be done by comparing other data. For example, a comparison using PRN-IDs can be used to determine. [0079] If the received signal is transmitted from a certain GPS satellite, the determining module 416 forwards the data received from the specified signal to the positioning module outside 432. The data obtained from this signal includes navigation data. If the received signal is emitted from transmitters for operation in interiors 200-1 or similar, the determining module 416 forwards the data obtained from this signal to the positioning module in interiors 434. These data represent predetermined coordinates as data for determining the position of the transmitter for indoor use 200-1. According to another aspect, a number identifying the transmitter may be used.

[0080] In beacon processor 430, the outside positioning module 432 performs the process of calculating the position of the device providing position information 100 based on the data provided from the determining module 416. In particular, the outdoor positioning module 432 calculates the propagation time of each signal using data contained in signals emitted from three or more (preferably four or more) GPS satellites and finds the position of the device providing positioning information 100 based on the calculation results. Process this is carried out using the known satellite positioning method. This process is easy to understand for a person skilled in the field and therefore its detailed description will not be repeated here.

[0081] On the other hand, when the position information device 100 is inside, in the navigation processor 430 the interior positioning module 434 performs the positioning process based on the output of the determining module 416. As will be described below, an interior transmitter 200 -1 emits a positioning signal containing data (time data) for determining iokaiization. Therefore, if the device providing position information 100 receives such a signal, this data can be taken from the signal and the data can be used as the position of the device providing position information 100. This process is implemented by the positioning module in interiors 434. Data calculated by the positioning module on Outdoor 432 or indoor positioning module 434 are used for display on the 440 display. In particular, this data is included in the image display data, and an image showing the measured position or displaying the location where the indoor transmitter 200-1 is installed is generated and displayed on a display 440. [0082] Positioning signal transmitted from the transmitter will be described with reference to Fig. 5. Fig. 5 shows the structure of the signal 500 emitted by a transmitter mounted on a GPS satellite. The 500 signal is made of five 300-bit subframes, i.e. subframes 510 to 550. Subframes 510 to 550 are cyclically transmitted by the transmitter. Each of the subframes 510 to 550 contains 300 bits transmitted at 50 bps (bits per second). So in this example, each subframe is transmitted for 6 seconds.

[0083] The first sub-frame 510 includes a transport header 511 of 30 bits length, time information 512 of 30 bits length and message data 513 of 240 bits length. The time information 512 includes in particular the time information obtained when generating the subframe 510 and the subframe identifier (ID). The subframe identifier here represents the identification number to distinguish the first subframe 510 from other subframes. Message data 153 includes GPS week number, clock information, GPS satellite status information, and orbit accuracy information.

[0084] The second subframe 520 includes a transport header 521 of 30 bits length, time information 522 of 30 bits length and message data 523 of 240 bits length. Time information 522 has the same structure as time information 512 from the first subframe 510. Message data 523 includes an ephemeris. Ephemeris (broadcast ephemeris) here represents information about the orbit of the satellite emitting the positioning signal. The ephemera is very accurate information successively updated by the control station supervising satellite navigation.

[0085] The third subframe 530 has the same structure as the second subframe 520. In particular, the third subframe 530 includes a transport header 531 length 30 bits long, time information 532 length 30 bits and message data 533 length 240 bits, the time information has same structure as time information 512 from the first subframe 510. Message data 533 includes an ephemeris, [0086] The fourth subframe 540 includes a transport header 541 of 30 bits length, time information 542 of 30 bits length and message 543 of 240 bits length. Unlike other message data 513, 523, 533, message data 543 contains almanac information, satellite status summary information, ionospheric delay information, UTC (Coordinated Universaf Time) and the like. [0087] The fifth subframe 550 includes a transport header 551 of 30 bits length, time information 552 of 30 bits length and message data 553 of 240 bits length. Message data 553 contains almanac information and information summarizing the state of the satellite. Each of the message data 543 and 553 consists of 25 pages, and each page has different pieces of information described above. The almanac information here represents the schematic orbit of the satellites and contains information not only about the actual satellite, but also about all GPS satellites. When the transmission of subframes 510 to 550 is repeated 25 times, the process returns to the first page and the emission of the same pieces of information begins again.

[0088] Subframes 510 to 550 are transmitted from each of the transmitters 120, 121 and 122. When subframes 510 to 550 are received by a device providing position information 100, the position of the device providing position information 100 is calculated based on each piece of service information / management contained in transport headers 511 to 551, time information 512 to 552 and message data 513 to 553.

[0089] Signal 560 has the same data length as each message data 513 to 553 contained in subframes 510 to 550. Signal 560 differs from subframes 510 to 550 in that instead of information about the orbit represented in the form of ephemeris (message data 523, 533) it has data representing the position of the source of signal emission 560, [0090] Signal 560 includes in particular PRN-ID 561 length 6 bits, transmitter ID (ID) 562, 15 bits long, X 563 coordinate value, Y 564 coordinate value, Z 565 coordinate value, height correction factor (Zhf) 566, address 567 and reserve field 568. Signal 560 is transmitted from transmitters for indoor operation 200-1, 200-2 and 200-3, instead of message data 513 to 553 contained in subframes 510 to 550.

[0091] The PRN-ID 561 is the identification number of the code patterns of the pseudo-string code group assigned in advance to the transmitters (e.g., transmitters for indoor operation 2001, 2003 and 200-3) as sources of 560 signal emission. Although PRN-ID 561 is different from the code number identification numbers of the pseudo-noise code group assigned to proper transmitters mounted on GPS satellites, they are numbers assigned to code patterns generated from the code sequence of the same system. When the device providing position information receives any of the pseudo-noise code patterns assigned to transmitters for indoor operation, it becomes possible to determine from the received signal 560 whether this signal corresponds to subframe 510 to 550 transmitted from the network, or the signal 560 transmitted from the transmitter to work in interiors.

[0092] The X 563 coordinate value, the Y 564 coordinate value, and the Z 565 coordinate value are data representing the position in which the transmitter for indoor operation 200-1 is mounted. For example, the X 563 coordinate value, the Y 564 coordinate value, and the Z 565 coordinate value indicate latitude, longitude, and altitude, respectively. The height correction factor 566 is used to correct the height specified by the Z 565 coordinate value. A height correction factor of 566 is not an essential element of data. Therefore, if an accuracy greater than the height specified in the Z 565 coordinate value is not needed, this factor may not be used. In this case, for example, the area assigned to the height correction factor 566 is stored, for example, NULL.

[0093] The control structure of the device providing position information 100 will be described with reference to Fig. 6. Fig. 6 is a flowchart showing the process implemented by the baseband processor 410 and the navigation processor 430 of the device providing position information 100.

[0094] In step S610, the position information device 100 obtains (tracks and acquires) a positioning signal. In particular, the baseband processor 410 receives the received positioning signal (data after digital conversion) from the A / D converter 408 as input, the baseband processor 410 generates, as a replica of the pseudo-noise code, a code pattern with a different phase that reflects the possible delay and detects the presence / no correlation between the code pattern and the received positioning signal. The number of generated code patterns is, for example, twice the number of bits of the code pattern. Suppose, for example, that the chip rate is 1023 bits. You can then generate 2046 code patterns, each with a delay, i.e. a half-bit code phase difference. The process of determining the correlation with the received signal is carried out using each code pattern. When an output level not lower than a predetermined value is detected in the correlation process, the baseband processor 410 blocks this code pattern and can determine the satellite that emitted the positioning signal based on this code pattern. There is only one pseudo-noise code with a bit sequence of a given code pattern. Therefore, the pseudo-noise code used to encode the spectrum spread of the received positioning signal may be determined.

[0095] As will be described later, the process of determining the correlation between the signal obtained as a result of the receipt and the locally generated code pattern replica may be implemented as a parallel process.

[0096] At step S612, the baseband processor 410 determines the source of the positioning signal emission. In particular, the determining module determines the signal emission source based on the PRN-ID identifier (see memory 420 in Fig. 4) corresponding to the transmitter that uses the code pattern for the pseudo-noise signal used during modulation to generate the signal. If the positioning signal has been emitted externally, the control proceeds to step S620. If the positioning signal was emitted in the interior, the control goes to step S630, If a number of received signals includes signals emitted outside and inside, the control goes to step S640. [0097] In step S620, the position information device 100 demodes the positioning signal, thereby obtaining the data contained in that signal. In particular, the positioning module outside 432 of the beacon processor 430 imposes a code pattern temporarily stored in memory 420 (the "locked" code pattern described above, referred to herein as the "locked code pattern") on the positioning signal to obtain a beacon from the signal forming frames. At step S622, the positioning module 432 performs the usual navigational message process for calculating position using four or more obtained navigational messages.

[0098] At step S624, the outdoor positioning module 432 performs the process by which the position of the device providing position information 100 is calculated. For example, if the device providing position information 100 has received positioning signals emitted from four or more satellites, distance calculation is performed using orbit information, time information and similar information of each satellite contained in the navigation message demodulated from each signal.

[0099] According to another aspect, if the device providing position information 100 has received the positioning signal emitted by the satellite (external signal) and the signal emitted by the transmitter for indoor operation (signal from the inside) (i.e. when step S624 is performed after step S642 ), the signal used to calculate the position is determined by the strength of the signals from inside and outside. For example, if the signal from the interior is more intense than the signal from the outside, the signal from the interior is selected and the coordinate values ​​contained in the signal from the interior are used as the position of the device providing position information 100.

[0100] In step S630, the position information device 100 demodises the positioning signal to obtain the data contained in that signal. In particular, the indoor positioning module 434 imposes a locked code pattern on the positioning signal transmitted from the baseband processor 410, wherein the message data is obtained from under the frames forming the positioning signal. The message data is contained in the positioning signal emitted by the transmitter for indoor use instead of the navigation message data contained in the positioning signal transmitted from the satellite. Therefore, it is preferred that the length of the message data is the same as the navigation data.

[0101] In step S632, indoor positioning module 434 obtains coordinate values ​​from data (i.e., data indicating the installation location of the transmitter for indoor use (e.g., coordinate X 563, coordinate Y 564 and coordinate Z 565 from signal 560 shown in Fig. 5)). If textual information representing the place of installation or the place of installation is contained in the frame instead of such coordinate values, such textual information is obtained.

[0102] In step S640, the position information device 100 demodulates the positioning signal, thereby obtaining data contained in that signal. In particular, outdoor positioning module 432 imposes a locked code pattern on the positioning signal transmitted by the baseband processor 410 to obtain data from the subframe creating the positioning signal. It follows that the device providing information about position 100 receives both the satellite signal and the signal from the transmitter for indoor work, and therefore works in the so-called "hybrid" mode. Thus, a signal with synchronized time data is obtained from the signal from each satellite, and from the signal from the transmitter for indoor operation, position data such as coordinate values ​​and the like mentioned above is obtained.

[0103] In step S642, indoor positioning module 434 performs the process of obtaining the X 563 coordinate value, Y 564 coordinate value, and Z 565 coordinate value from the positioning signal emitted by the transmitter for indoor operation 200-1, and obtains and processes the navigational message from the positioning signal emitted by a GPS satellite. Then the control goes to step S624.

[0104] At step S650, the navigation processor 430, based on the result of the position calculations, performs the process of displaying position information on the display 440. In particular, image data is generated and transmitted to the display 440 for displaying the obtained coordinates or data for displaying the transmitter installation location for operation. in the interiors 200-1. Based on such data, the display 440 displays in the display area the position information of the device providing position information 100.

[0105] A method of displaying position information of a device providing position information 100 will be described with reference to Fig. 7. Fig. 7 is an image display on the display 440 of the device providing position information 100. When the device providing position information 100 receives the positioning signal emitted from each outdoor GPS satellite, the display 440 displays an icon 710 indicating that position information is received based on the positioning signal. When the user of the position information device 100 moves inside, the position information device 100 can no longer receive the positioning signal emitted from any GPS satellite. Instead, the device providing position information 100 receives a signal emitted, for example, by a transmitter for indoor use 200-1. This signal is transmitted in the same way as the positioning signal emitted from the GPS signal as described above. Therefore, the device providing position information 100 performs on the signal the same process as that performed when the positioning signal is received from the satellite. When the position information device 100 obtains position information from the signal, a display icon 720 is displayed on the display 440 indicating that the position information is obtained based on a signal emitted from an indoor transmitter.

[0106] As described above, the device providing position information 100 according to the first embodiment of the present invention in places where a radio wave from a GPS satellite cannot be received, such as interiors or shopping centers, receives a radio wave emitted from a transmitter (such as transmitters for indoor use 200-1, 200-2 and 200-3) installed here. The device providing position information 100 obtains from this radio wave information indicating the position of the transmitter (such as coordinate values ​​or address) and displays it on the display 440. Thus, the user of the device providing position information 100 knows where he is at the moment. In this way, position information can be provided even in a place where the positioning signal cannot be received directly.

[0107] In this way, stable indoor signal reception becomes possible. In addition, even indoors, position information can be provided with stable accuracy of several meters.

[0108] Ground time (time of a transmitter such as a transmitter for indoor use 200-1) and satellite time can be independent of each other and synchronization is unnecessary. Therefore, the cost of producing transmitters for indoor use is not significantly increased. In addition, once the position information system is operational, it is not necessary to provide time synchronization for transmitters for indoor use, and thus operation is simple.

[0109] Each signal emitted from each transmitter for indoor use includes information indicating the location where the transmitter is installed. Therefore, it is not necessary to calculate position information based on signals emitted from a number of satellites, and therefore position information can be extracted from a signal emitted from one transmitter.

[0110] Furthermore, as the signal emitted from one transmitter for indoor operation is received, the position at which the signal is received can be indicated. Therefore, such a positioning system can be implemented in a simple manner compared to other conventional positioning systems such as GPS.

[0111] The device providing position information 100 does not require dedicated equipment to receive the signal emitted by the transmitters for indoor operation 200-1, and can be implemented using equipment for implementing a conventional positioning system. Therefore, there is no need to design from the outset the equipment implementing the technique of the present invention, and thus the cost of the device providing position information 100 can be prevented by promoting its more widespread use. In addition, a position information device may be provided that does not increase or complicate the scale of the system.

[0112] In particular, the memory 420 of the position information device 100 stores PRN-IDs predefined for an indoor transmitter and / or satellite. The device providing information about position 100 has a program of the process of determining on the basis of the PRN-iD identifier whether the received radio wave is emitted from the satellite or from the transmitter for indoor use. This program is implemented by an arithmetic processing module such as a baseband processor. Alternatively, the circuit element to be determined may be converted into a circuit element comprising functions performed by a program with which a device providing position information 100 can be created.

[0113] If the device providing position information 100 is implemented as a mobile telephone, the information obtained may be stored in a non-volatile memory 420, such as fiash memory. When broadcast from a mobile telephone, the data stored in the memory 420 may be transmitted to the target recipient. Due to this approach, information about the position of the emission source, i.e. position information obtained by the device providing position information 100, such as a mobile telephone, from a transmitter for indoor use, is sent to the base station that transmits communication. The base station stores this position information as a communication entry, along with the date and time of receipt. If the destination is an emergency number (110 in Japan), information on the position of the emission source can be reported directly. Thus, just like conventional reporting of an emergency call source from a landline, it becomes possible to report an emission source from a mobile facility.

[0114] Relative to a transmitter installed at a particular location, a transmitter adapted to emit a signal similar to that emitted by a transmitter mounted on a positioning satellite may be used to implement the position information system. Therefore, designing the transmitter from the beginning becomes unnecessary.

[0115] The position information system according to the present embodiment uses the spread spectrum signal as the positioning signal. Transmitting this signal can reduce the electrical power per frequency unit, and thus managing radio waves can be simpler compared to a conventional RF tag. As a result, the design of the system providing position information becomes simpler.

<First modification>

[0116] Hereinafter, the first modification of the present embodiment of the invention will be described with reference to Fig. 8. The structure of the signals transmitted from different transmitters is not limited to that shown in Fig. 5. Fig. 8 shows the structure of the signal according to the present modification. According to this modification, six sub-frames are broadcast. As a first frame, the transmitter transmits 810 signal. Signal 810 includes transport header 811 length 30 bits, time information 812 length 30 bits, PRN-ID 813 length 6 bits, transmitter ID 814 length 15 bits, coordinate value X 815, coordinate value Y 816 and coordinate value Z 817. The first 60 bits of the 810 signal are the same as the first 60 bits of each of the 510 to 550 subframes emitted by the GPS satellite.

[0117] As the second under the frame, the transmitter transmits the signal 820. The signal 820 contains the identifier (ID) of the 6-bit length subframe, height correction factor 822 and the address of the transmitter position 823, The third to sixth subframes are also transmitted in a similar manner by defining different information fragments in 144 bits (in signal 820 height correction factor 822 and address information position 823) following signal subframe identifier 820. The information contained in each subframe is not limited to those described above. For example, ads associated with position information, website URLs (Uniform Resource Locators) and the like may be stored in predefined areas.

[0118] Signal 830 shows an example of transmission of signals 810 and 820 described above and subframes three to six having the same structure as signal 820. In particular, signal 830 has a first subframe 831 and a second subframe 832. The first subframe 831 has the same header , as subframes 510 to 550 broadcast from a GPS satellite. The second subframe 832 corresponds to signal 820.

[0119] Signal 840 includes a first sub-frame 831 and a third sub-frame 842. The first sub-frame 831 is the same as the first sub-frame 831. The third sub-frame has the same structure as signal 820.

[0120] This structure is repeated at signals 870 for transmitting the sixth subframe 872. Signal 870 includes the first subframe 831 and the sixth subframe 872.

[0121] If the transmitter cyclically transmits signals 830 to 870, it follows that the first sub-frame 831 is transmitted each time each of the signals is transmitted. After the first 831 subframe has been assigned, any of the other subframes is interpolated. In particular, the order of sending individual frames is as follows: first subframe 831 -> second subframe 832 first subframe 831 third subframe 842 -> first subframe ... sixth subframe 872 first subframe 831 -> second subframe 832 ....

<Second modification>

[0122] The second modification will be described below. The structure of the message data can be defined independently of the subframes 510 to 550. Fig. 9 schematically shows the structure of the signal 910 according to the present modification. Referring to Fig. 9, signal 910 includes transport header 911, preamble 912, PRN-ID 913, transmitter identifier (ID) 914, first variable 915, coordinate value X 916, coordinate value Y 917, coordinate value Z 918, and parity / code. CRC 919. Signal 920 has a structure similar to signal structure 910, and instead of the first variable 915 of signal 910 contains a second variable 925.

[0123] Each signal is 150 bits long. Six signals of the same structure are emitted. A signal with this structure can be formed as a signal emitted from a transmitter for indoor use.

[0124] Each signal shown in Fig. 9 has a PRN-ID, and therefore the device providing position information 100 has the ability to indicate based on this PRN-ID the source of the received signal transmission. If the transmission source is a transmitter for indoor operation, the signal contains X, Y and Z coordinate values. Therefore, a device providing position information 100 can display the position in the interior.

<Third modification>

[0125] Instead of the structure of the correlator module 412 of the device providing position information 100, a number of correlators may be used. In this case, the positioning and replica signal matching processes are performed simultaneously and in parallel, and therefore the time for calculating position information is reduced.

[0126] The apparatus providing position information 100 according to the present modification includes antenna 1010, bandpass filter 1020 electrically connected to antenna 1010, low noise amplifier 1030 electrically connected to bandpass filter 1020, frequency conversion 1040 electrically connected to low noise amplifier 1030 , 1050 bandpass filter electrically connected to a down-conversion 1040, A / D converter (analogue-digital, Anaiog-to-Digital) 1060 electrically connected with a 1050 bandpass filter, 1070 parallel correlator, containing a number of electrically connected correlators with A / D 1060 converter, 1080 processor electrically connected with 1070 parallel correlator and 1090 memory electrically connected with processor 1080.

[0127] Parallel correlator 1070 contains n correlators 1070-1 to 1070-n. These correlators simultaneously perform matching of the received positioning signal to the code pattern generated by the demodulation of the positioning signal, based on the output control signal from the 1080 processor, [0128] In particular, the 1080 processor gives each parallel correlator 1070 a command to generate a code pattern (with a code phase shift) ) reflecting the possible delay of the pseudo-noise code. The command will be the number of satellites x 2 x 1023 (the length of the code pattern for the pseudo-noise code used). Each 1070 parallel correlator generates, based on the command given to it, a code pattern with a different code phase, using the pseudo-noise code pattern defined for each satellite. Then it follows that among all the generated code patterns there is one pattern that matches the pseudo-noise code pattern used to modulate the received positioning signal. Therefore, thanks to the prior preparation of the number of correlators needed for the matching process using individual code patterns in the form of a 1070 parallel correlator, the pattern of pseudo-noise code can be indicated immediately. This process is similarly applicable when the device providing position information 100 receives a signal from the transmitter for indoor use. Therefore, even when the user of the position information device remains indoors, position information can be obtained immediately.

<Second embodiment of the invention>

[0129] In the following, a second embodiment of the present invention will be described. The position information system of the present embodiment differs from the first embodiment in that a number of transmitters are mounted.

[0130] Fig. 11 illustrates how a device providing position information according to a second embodiment of the present invention is used. Referring to Fig. 11, transmitters for indoor use 1110, 1120 and 1130 are mounted on the ceiling of the same floor. Each indoor transmitter performs the same process that is performed by the 200-1 indoor transmitter described above. In particular, each indoor transmitter emits a positioning signal containing data representing the location where it is installed.

[0131] Depending on the mounting position of the transmitters for indoor use, there may be an area (or space) in which signals transmitted from adjacent transmitters may be received. For example, in area 1140, signals emitted from transmitters for indoor operation 1110 and 1120 may be received. Similarly, positioning signals emitted from transmitters for indoor operation 1120 and 1130 may be received in area 1150, [0132] Therefore, assuming that the position information device 1160 of the present invention is in the position shown in Fig. 11, the device providing position information 1160 can obtain data representing the mounting position of the indoor transmitter 1110 contained in the signal emitted from the transmitter for indoor operation 1110 as the position of the device providing position information 1160. After which, for example, when the user of the position information device 1160 moves to the position corresponding to area 1140, the position information device 1160 can also receive the signal emitted by the transmitter for indoor operation 1120, in addition to the signal from the transmitter for indoor operation 1110. In this case, the one in which the signal contains the positioning data to be used as the position of the position information device 1160 can be determined based on the strength of the received signals. In particular, if signals emitted from a number of transmitters for indoor operation are received, the data of the one with the highest intensity can be used to display position information. If the signals are of equal intensities, the arithmetic sum of the data contained in these signals can be derived and used as the position of the device providing position information 1160.

[0133] As described above, even if a number of positioning signals are received in the room, the position information device 1160 of the present embodiment can determine the emission source of any of them, and thus can determine the position of the emission source, i.e. the position of the installed transmitter Inside.

[0134] The meaning of the word "interior" is not limited to the interior of a building or other structure, and means any place where a radio wave emitted from a GPS network cannot be received. Shopping centers or rail vehicles can attach themselves to such places.

<Third embodiment of the invention>

[0135] A third embodiment of the present invention will be described below. The position information device of the present embodiment differs from the above-described embodiments in that instead of determining the position based on the data contained in the transmitter for indoor use, the transmitter identification data is sent to the device providing information about the transmitter, so that it can be position information obtained.

[0136] Fig. 12 illustrates a method in which a device providing position information according to the present embodiment is used. The device providing position information is implemented, for example, as a mobile telephone 1200. The mobile telephone 1200 can receive the positioning signal emitted by the transmitter for indoor use 1210. The transmitter for indoor use 1210 is connected to the 1220 internet network. The 1220 Internet is connected to a 1230 information server that can provide information about the transmitter for indoor use 1210. The Internet is also connected to a 1240 base station for communication with a 1200 mobile phone.

[0137] When the mobile telephone 1200 receives the signal emitted by the transmitter for indoor use 1210, it obtains from this signal the transmitter ID for identifying the transmitter for indoor use 1210. For example, the transmitter identifier corresponds to the PRN-ID identifier described above. Mobile telephone 1200 sends the transmitter identifier (optionally with PRN-ID) to the server providing information 1230. In particular, mobile telephone 1200 starts communication with the base station 1240 and sends a data packet containing the received transmitter identifier to the server providing information 1230.

[0138] Recognizing the transmitter identifier, the information server 1230 makes reference to the transmitter identifier database and reads the positioning data associated with that identifier. When the server providing information 1230 transmits data to base station 1240, base station 1240 emits this data. Teiefon portable 1200 detects the arrival of this data and, in accordance with the user's browsing operation of the mobile telephone 1200, obtains the position of the transmitter 1210.

[0139] The structure of a mobile telephone will be described here with reference to Fig. 13. Fig. 13 is a block diagram illustrating the hardware configuration of portable teiefon 1200. Teiefon Portable 1200 includes antenna 1308, communication device 1302, CPU 1310, operating button 1320, camera 1340, fiash 1344 memory, RAM 1346 memory, ROM 1348 data memory, 1380 memory card drive, 1370 voice signal processing circuit, microphone 1372, 1374 loudspeaker, 1350 display, light emitting diode (LED) 1376, 1378 data communication interface (IF) and 1384 vibrator, all electrically connected together.

[0140] The signal received by the antenna 1308 is transmitted to the CPU 1310 by the communication device 1302. The CPU 1310 transmits this signal to the voice signal processing circuit 1370. The voice signal processing circuit 1370 performs a predefined signal processing on the signal and sends the processed signal to the speaker 1374 Based on this signal, the 1374 speaker plays the voice.

[0141] The microphone 1372 receives the speech directed to the mobile telephone 1200 and provides an output corresponding to the spoken voice to the voice processing circuit 1370. Based on this signal, the voice processing circuit 1370 performs a fixed signal processing for communication and sends the processed signal to the CPU 1310. The CPU 1310 converts this signal into data for transmission and transmits this data to communication device 1302. When communication device 1302 emits a signal via antenna 1308, base station 1240 receives this signal.

[0142] The fiash memory 1344 stores data transmitted from the CPU 1310. The CPU 1310 reads the data stored in the fiash memory 1344 and performs the established processes using this data.

[0143] RAM 1346 temporarily stores the data generated by the CPU 1310 based on the operation of the operating button 1320. The ROM 1348 data memory stores data or a program for causing portable telephone 1200 to perform a predetermined operation. The CPU 1310 reads this data or program from the ROM 1348 data memory and causes the mobile phone 1200 to follow a predetermined process.

[0144] The memory card drive 1380 adopts the memory card 1382 that is loaded into it. The memory card drive 1380 reads the data stored on the memory card 1382 and sends this data to the CPU 1310. The memory card drive 1380 writes the output from the CPU 1310 to the data storage area provided on memory card 1382.

[0145] The voice processing circuit 1370 performs a process as described above on the signal used for communication. The CPU 1310 and the voice processing circuit 1370 may be integrally formed.

[0146] Based on the output from the CPU 1310, the display 1350 displays an image defined by this data. For example, if fiash 1344 stores access data (e.g., URL) of the server providing information 1230, display 1350 displays that URL. [0147] LED 1376 performs a predetermined operation of emitting light based on a signal from the CPU 1310. For example, if the 1376 LED is adapted to display a number of colors, based on the data contained in the output from the CPU 1310, the 1376 LED emits light in the color associated with that data.

[0148] The data communication cable is connected to the data communication interface (IF) 1378. The data communication interface 1378 transmits the output signal from the CPU 1310 to the cable. Alternatively, the data communication interface 1378 forwards the data received from the cable to the CPU 1310.

[0149] The vibrator 1384 oscillates at a fixed frequency based on the output from the CPU 1310. The basic principles of operation of the mobile telephone 1200 are easy to understand for an expert in the field and therefore its detailed description will not be repeated here.

[0150] The specific configuration of the server providing information 1230 will be described with reference to Fig. 14, Fig. 14 is a block diagram showing the hardware configuration of the server providing information 1230. For example, the server providing information 1230 is implemented as a well-known computer system.

[0151] The Server providing Information 1230 includes, as main hardware components, a CPU 1410, mouse 1420 and keyboard 1430 to receive commands entered by the user of the server providing information 1230, RAM memory 1440 temporarily storing data generated during program execution by the CPU 1410 or data entered using a 1420 mouse or 1430 keyboard, 1450 hard drive that stores a large amount of non-volatile data, a CDROM drive Compact Disk-Read Only Memory) 1460, monitor 1480 and 1470 communication interface (IF). These hardware components are connected to each other via a data bus. The 1462 CD-ROM is inserted into the 1460 CD-ROM drive.

[0152] The process in the computer system implementing the server providing information 1230 is implemented by hardware ί software executed by the CPU 1410. The software may be previously saved to the hard disk 1450. Alternatively, the software may be stored on a data carrier such as CD-ROM 1460 or similar and distributed as a programming product. Alternatively, the software may be provided by another information provider connected to the Internet as a downloadable programming product. This software is read by a 1460 CD-ROM drive or other device that reads data from the storage medium or downloaded via the 1470 communication interface (IF) and is temporarily stored on the 1450 hard drive. This software is read from the 1450 hard drive by the CPU 1410 and stored as an executable program in RAM 1440. The CPU 1410 executes this program. [0153] The hardware elements of the computer system implementing the server providing information 1230, shown in Fig. 14, are typical. Therefore, an essential part of the server providing information 1230 according to the present invention may be software stored in RAM 1440, hard disk 1450, CD-ROM 1462 or other data carrier, or software downloadable via the network. The operation of computer system hardware components is well known. Therefore, its detailed description will not be repeated.

[0154] The storage medium is not limited to CD-ROM 1462, hard disk 1450 and the like described above and may be a medium that can carry the program in a fixed way, such as magnetic tape, tape cassette optical disk (MO Magnetic Opticai Disk) / MD (Mini Disc) / DVD (Digital Versatiie Disc)), chip card (including memory card), optical card or semiconductor memory, including masked ROM, EPROM, EEPROM and flash ROM.

[0155] Here, the program includes not only the program directly executable by the CPU 1410, but also the program in the form of source code, a compressed program or an encrypted program.

[0156] The data structure of the information server 1230 will be described with reference to Fig. 15. Fig. 15 schematically shows a method of storing data on a hard disk 1450. Hard disk 1450 includes areas 1510 to 1550 for storing data.

[0157] The record number for identifying the data record stored on the hard disk 1450 is stored in the area 1510. The transmitter identifier for identifying the transmitter emitting the positioning signal is stored in the area 1520. Data (coordinate values) representing the location where the transmitter is installed, are stored in area 1530. For example, data is saved to the 1450 hard drive each time a transmitter is installed. The correct name of the transmitter installation location is stored in area 1540. This data is used to enable the administrator managing the data stored on the 1450 hard drive (or the service provider providing position information using the 1230 information server). Data representing the address where the transmitter is installed is stored in the area 1550. This data is also used by the administrator, as is the data stored in area 1540. [0158] Transmitter position information is provided by the server providing information 1230 as follows. Mobile telephone 1200 generates a data packet requesting position information (hereinafter referred to as "request"), using the transmitter ID (ID) and access data (URL and similar) of the server providing information 1230, obtained from the result of determining the PRN-ID. The mobile telephone 1200 forwards this request to base station 1240. The handover is carried out by known communication processing. Upon request, base station 1240 forwards it to the server providing 1240 information.

[0159] The server providing information 1230 detects the receipt of the request. The CPU 1410 obtains the transmitter identifier from the request and searches for it on the hard disk 1450. In particular, the CPU 1410 performs the matching process to see if the received transmitter identifier matches the transmitter identifier stored in the area 1520. As a result of matching, if a transmitter identifier was found that matches the transmitter identifier contained in the data transmitted from the mobile telephone 1200, the CPU 1410 reads the coordinate values ​​(area 1530) associated with that transmitter identifier and generates a data packet to return the position information of the mobile telephone 1200. In particular, CPU 1410 adds mobile phone address 1200 to data containing coordinate values ​​to generate a data packet. The CPU 1410 sends this data packet to base station 1240 via the communication interface (IF) 1470.

[0160] After receiving the data packet sent by the server providing information 1230, base station 1240 emits the data packet based on the address contained in the data. The base station 1240 can store the received data packet and the reception time in a non-volatile storage device (such as a hard disk). This leaves the history of receiving position information by the user of the mobile 1200, and thus the user's path can be tracked.

[0161] When the mobile telephone 1200 is in radio range from base station 1240, it receives a data packet emitted by the base station 1240. When the mobile telephone user 1200 performs a fixed operation of viewing received data (such as an e-mail browsing operation), display 1350 displays transmitter coordinate values. Thus, the user has the opportunity to know the approximate position. With this approach, prior registration of the coordinates of each of the transmitters installed in the rooms becomes unnecessary. Thus, the transmitter installation location can be changed more flexibly.

[0162] As described above, according to the position information system of the present embodiment, the signal emitted from a transmitter provided on the Earth's surface must only contain data (transmitter identifier) ​​to identify the transmitter. In the server providing transmitter position information, this data is stored in connection with the position information. Mobile telephone 1200, acting as a device providing position information, receives position information by sending the transmitter identifier to the server. With this method of providing information, it is not necessary for the transmitter to store information about the position of the transmitter itself, and thus the installation position of the transmitter can easily be changed.

[0163] Embodiments as described herein are only examples and should not be construed as limiting. The scope of the present invention is defined by each of the claims, with due regard to the written description of the embodiments, and includes modifications in the scope of meaning and vocabulary equivalents in those claims.

Industrial Applicability [0164] The position information device of the present invention is applicable to a mobile telephone with positioning function, a portable positioning terminal, a portable monitoring terminal or other terminal adapted to receive a positioning signal. Furthermore, the transmitter of the present invention is applicable to a transmitter installed in a room or other transmitting devices.