JP6511275B2 - Mobile radio telephone and indoor radio system - Google Patents

Description

  The present invention relates to a portable wireless telephone and an indoor wireless system, and more particularly to a portable wireless telephone with reduced power consumption of a built-in GPS receiver and an indoor wireless system using the same.

  Conventionally, there is known an in-building wireless system in which the position of a terminal can be accurately grasped using indoor GPS technology called IMES (Indoor Messaging System) (see, for example, Patent Document 1). IMES installs an IMES transmitter that radiates a pseudo noise signal similar to that of GPS satellites with weak power indoors, and the GPS receiver that receives the signal can know the position of the IMES transmitter, that is, its own position. It is possible. The IMES transmitter directly transmits the IMES transmitter's absolute position information, floor (building floor) information, location information code (numbered by the Geographical Survey Institute), etc. in the same format as the navigation message transmitted by GPS satellites. Do. Since modulation scheme and frame configuration are common to IMES and GPS, it is easy to realize seamless positioning with a single receiver.

  In the local area wireless system of Patent Document 1, in order to manage the position of the wireless terminal, the wireless terminal transmits periodic position registration data to the control device (private branch exchange), and the control device transmits the wireless included in the periodic position registration data. The position of each wireless terminal is grasped by associating the terminal number of the terminal with the CS call area information relaying the regular position registration data and the position information received from the IMES transmitter.

  In the case of a private PHS (ARIB RCR STD-28), the area of one base station (CS: Cell Station) has a good area cover efficiency with a maximum output of 30 m to 100 m, but position management in CS call area units Therefore, while the accurate position management can not be performed, the output of the IMES transmitter is a weak radio wave with the upper limit value of about -94 dBW, so the cover area is as small as about 10 m and the area coverage is low, but accurate position measurement It has the opposite feature of being possible.

  In order to understand the position of the person who walks and moves without losing the accuracy of IMES, the wireless terminal needs to try to receive the IMES signal in a cycle (for example, 3 seconds) shorter than the transit time of the coverage area. is there.

As another prior art related to the present invention, the amount of movement is detected using an acceleration sensor and a gyro, and the battery consumption is reduced by activating the GPS receiver each time the amount of movement becomes a constant value. A position detection notification device is known (see Patent Document 2).
There is also known a GPS receiver that performs intermittent operation (see Patent Document 3).
In addition, a device for transmitting absolute position information by infrared rays is provided, and when there is a deviation between the absolute position information obtained from the device and the current position, a walking navigation device is known which corrects the position according to the absolute position information Patent Document 4).

JP, 2012-070082, A Japanese Patent Application Laid-Open No. 11-083529 Patent No. 4177585 JP 2002-139340 A

  However, when the wireless terminal continues intermittent reception of GPS / IMES, there is a problem that battery consumption is intense. As described above, when the position detection by IMES is performed every three seconds, that is, when the GPS / IMES receiver is operated, the battery of the wireless terminal has only about 13 hours in the standby state and about 6 hours in the continuous call.

  The present invention has been made in view of the above problems, and it is possible to extend the usable time of the GPS / IMES mounted wireless terminal by reducing the IMES reception frequency and suppressing the power consumption while maintaining the position accuracy, and the indoor wireless It aims to provide a system.

  A portable radio telephone according to an aspect of the present invention is used in the indoor radio system provided with a plurality of IMES (Indoor Messaging System) transmitters constituting a cover area, and provided with a terminal located in the cover area, as the terminal Portable radio telephone, which acquires a PRN code specifying an IMES transmitter to be captured from radio waves transmitted from each of the plurality of IMES transmitters, and transmits IMES corresponding to the acquired PRN code Position detection means for detecting the position of the own terminal by receiving radio waves transmitted from the aircraft, acceleration detection means for detecting acceleration due to movement of the own terminal, and the previous time when the position detection means is turned off The storage means for storing the PRN code corresponding to the captured IMES transmitter, and the movement distance of the own terminal from the detection result of the acceleration detection means Therefore, it is determined whether the movement distance of the own terminal exceeds a threshold from the time when the position detection means is off, and when the threshold is exceeded, the position detection means is turned on and the PRN stored in the storage means And control means for causing the position detection means to detect the position of the own terminal based on the code.

  The indoor wireless system according to another aspect of the present invention is a portable wireless system located in a cover area formed by a plurality of IMES transmitters each forming a cover area and at least one IMES transmitter among the plurality of IMES transmitters. The portable radio telephone acquires a PRN code for specifying an IMES transmitter to be captured from radio waves transmitted from each of the plurality of IMES transmitters, and corresponds to the acquired PRN code. When the position detection means for detecting the position of the own terminal by receiving the radio wave transmitted from the IMES transmitter to be detected, the acceleration detection means for detecting the acceleration due to the movement of the own terminal, and the position detection means being turned off Storage means for storing a PRN code corresponding to the IMES transmitter captured last time, and the addition from the time when the position detection means is off It is judged whether the movement distance of the own terminal obtained by the degree detection means exceeds a threshold, and when the threshold is exceeded, the position detection means is turned on and the previously obtained position information is obtained by the IMES transmitter. And control means for causing the position detection means to detect the position of the own terminal based on the PRN code stored in the storage means.

  According to the portable wireless telephone of the present invention, it is possible to extend the usable time of the GPS / IMES mounted wireless terminal by reducing the reception frequency of IMES and suppressing the power consumption while maintaining the position accuracy.

  As an additional effect, if the position detection with the acceleration sensor is successful, the number of IMES transmitters installed can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic block diagram of the local radio system of one Embodiment of this invention. FIG. 1 is a hardware configuration diagram of a mobile wireless telephone according to a first embodiment of the present invention. FIG. 1 is a hardware block diagram of a GPS / IMES receiver of a mobile wireless telephone according to a first embodiment of the present invention. 3 is a flowchart of position detection processing of the mobile wireless telephone according to the first embodiment of the present invention. FIG. 2 is a class diagram of a CS-IMES dictionary held by the mobile wireless telephone according to the first embodiment of the present invention. The state transition diagram which shows the position detection process of the portable wireless telephone in Example 2 of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram illustrating the basic idea of an embodiment of the present invention.

  The IMES transmitters 1, 2 are usually arranged such that their coverage areas 3, 4 do not overlap excessively. Once the portable radio telephone 5 having received the signal of the IMES transmitter 1 does not receive the IMES signal until it exits the cover area 3 or may enter the cover area 4 of another IMES transmitter 2 There is almost no problem. As long as the mobile radio telephone 5 receives the same signal each time as long as it stays within the cover area 3 of the IMES transmitter 1, it should be noted that the mobile radio telephone 5 is not out of the cover area 3 of the IMES transmitter 1 If it is known with sufficient accuracy, the GPS / IMES receiver of the portable wireless telephone 5 can be put to sleep.

  Even if it is not out of the area, the GPS / IMES receiver is activated every predetermined time (for example, one minute). However, the pseudo random noise (PRN) code of the IMES transmitter to be captured is uniquely determined, and the carrier offset can be captured at high speed by using the previous result. As soon as I can capture, I go back to sleep. The radio wave transmitted by the IMES transmitter includes the PRN code and information representing the absolute position of the IMES transmitter. Position information is represented by latitude and longitude.

  FIG. 2 is a hardware configuration diagram of a portable radio telephone (including a PHS terminal) 5 according to the first embodiment of the present invention.

  The RF unit 11 is an analog circuit for transmitting and receiving radio signals in the 1.9 GHz band. The L1 processing unit 12 performs processing of the layer 1 of PHS, and performs channel coding (modulation / demodulation) processing, bit synchronization / frame synchronization, error detection, and the like.

  The L2 processing unit 13 performs processing of layer 2 of PHS, performs frame / deframe conversion, and provides conversion between a physical slot and a functional channel.

  The ADPCM unit 14 speech-decodes data of TCH (Traffic Channel) from the L2 processing unit 12 and outputs it to a speaker, and also encodes an audio signal from a microphone and outputs it to the L2 processing unit 12.

  The CPU 15 executes part of layer 2 processing (link establishment and the like) of PHS, layer 3 processing (call control, mobility management, wireless management and the like), application processing and the like. The movement management of layer 3 processing includes position registration processing. The application processing includes a function of holding GPS assist data transmitted from the network side and providing it to the GPS / IMES receiver 16 in addition to the functions (phonebook function, mail function) of a general portable wireless telephone . The mobile radio telephone 5 of this example may transmit IMES acquisition information to the network side together with the location registration request message and the location registration area report (simultaneously) using FACCH (Fast Associated Control Channel) as an example. it can.

  The GPS / IMES receiver 16 is a GPS receiver whose firmware has been improved so that it can handle IMES signals, and when an IMES signal is received, the IMES acquisition information (IMES message) is extended on its own NMEA 0183 sentence and serialized. Output as a signal. Furthermore, IMES priority capture and IMES hot standby function (described later) are provided.

  The acceleration sensor 17 is a three-axis acceleration sensor capable of detecting a static acceleration (gravity), calculates the movement acceleration of the portable wireless telephone 5, and converts the A / D converted acceleration signal at predetermined intervals into a serial interface. Output to The acceleration sensor 17 may be capable of generating an interrupt signal to the CPU 15 when detecting an acceleration equal to or greater than a predetermined threshold.

The keypad 18 is a push button group that receives a user's operation.
The key controller 19 scans the state of the keypad 18, and when the button is pressed, the CPU 15 generates an interrupt and buffers the key code.

  A dot matrix LCD (liquid crystal display) 20 displays a plurality of lines of strings, simple icons (pictograms), and the like, and provides a user with a visual interface. The LCD controller 21 performs control of drawing a character on the dot matrix LCD 20 and scrolling the display.

  The ROM 22 is, for example, a NOR type flash memory, and stores an OS, a program and data (firmware) that the CPU 15 executes.

  The RAM 23 is, for example, an SRAM, and holds temporary data. This data may include a GPS assist data received from the network side, a dictionary in which CS-IDs and the PRES of IMES are associated.

  The timer 24 is a device called, for example, a programmable timer / counter or the like, and generates a timer interrupt at a designated time.

  The external I / F 25 is, for example, USB (trademark), and is used for rewriting of firmware, a user, reading and writing of data, and the like. It also interfaces with industrial keypads / touch panels and card readers / writers.

  FIG. 3 is a hardware block diagram of the GPS / IMES receiver 16 of the mobile wireless telephone 5 of the first embodiment. The GPS / IMES receiver 16 of this example assumes that almanac data / ephemeris data as GPS assist data as well as time information is provided from the PHS network, and processes for demodulating navigation messages transmitted from GPS satellites I hardly need it.

  The RF front end 31 is a high frequency circuit that receives at least the L1 band (1575.42 MHz), and includes a SAW filter, a low noise amplifier, a mixer, and the like.

  The A / D converter 32 A / D converts the output of the RF front end 31 and finally outputs an orthogonal signal consisting of I and Q phases having a sample rate of about 4 times the chip rate (1.023 Mcps). .

  Capturer 33 is hardware that captures GPS / IMES signals arriving at unknown timing with high speed and low power consumption, and FFT (fast) that converts received signals (orthogonal signals) from time domain signals to frequency domain signals. fourier transform) an operator 331, a bin / shifter 332 frequency-shifting the output of the FFT operator 331 by Δf, a code generator 333 providing an FFT PRN code, and corresponding bins of the respective signals. And an IFFT operator 335 for returning the output of the multiplier 334 to a time domain signal in which a correlation peak appears.

  Tracker (tracker) 34 is hardware that keeps the phase of the code and the carrier frequency synchronized with the GPS / IMES signal whose PRN code and its phase (timing) are known. Be For synchronization of code phase and carrier frequency, known techniques such as DLL (delay lock loop) and AFC (automatic frequency control) are used. The tracker 34 in this example processes the mid path of the DLL with a decision feedback equalizer, and outputs a symbol-decided (demodulated) signal. A phase change is detected from the equalization error of the decision feedback equalizer and is used for AFC control.

  In the tracker 34, the quadrature signal output from the A / D converter 32 is supplied to the multiplier 341, multiplied by the carrier frequency signal generated from the oscillator 342, and output to the multipliers 343, 344, 345. . Also, the PRN code generated from the code generator 346 is supplied to the multiplier 345 and also delayed for a predetermined time by the delay unit 347 and supplied to the multiplier 344. The output signal of the delay unit 347 is delayed by a predetermined time by the delay unit 348 and supplied to the multiplier 343. The multiplier 343 multiplies the GPS / IMES signal converted into the digital signal by the PRN code, and outputs the multiplication result to the integrator 349. The integrator 349 integrates the output signal of the multiplier 343 and outputs the integration result to the CPU 35 and the multiplier 3410 as a demodulation signal.

  The multiplication result including the code phase output from the multiplier 344 is supplied to the equalizer 3411 to perform phase equalization, and the equalization error value is supplied to the CPU 35 and the differentiator 3412. The differentiator 3412 detects a phase error from the equalization error value. The phase error value passes through the PLL filter 3413 to extract the low frequency component fd and is provided to the AFC of the oscillator 342.

  On the other hand, the output signal of the multiplier 345 is integrated by the integrator 3414 and supplied to the multiplier 3410. The multiplier 3410 multiplies the output signal of the integrator 349 by the output signal of the integrator 3414 and outputs the multiplication result to the time difference detector 3415. The time difference detector 3415 detects a time error from the input multiplication result. This detection result passes through the DLL filter 3416 and is subjected to delay lock for the code generator 346.

  When there is a satellite or IMES transmitter that can be newly captured, the CPU 35 designates the PRN code in the capturer 33 to capture it, acquires the result (correlated waveform), and coherently adds it. The phase, carrier frequency offset, received power, etc. are calculated. When there is a satellite that can be tracked based on the received power and the like, the tracking unit 34 specifies a code phase, a carrier frequency offset, and the like to cause tracking and acquires a demodulated signal.

  When the CPU 35 can capture / track three or more satellites, it performs positioning calculation based on the code phase, ephemeris data, and the like. If the correct time is found in the process, calibrate the time indicated by the built-in high precision timer. If positioning / position detection is successful, the time, reception status, etc. are held in the built-in RAM.

  When the CPU 35 sleeps according to a program instruction, the CPU 35 stops the operation (clock supply) except for a part of the configuration such as the high precision timer. Thereafter, almost no power is consumed until an interrupt is generated due to a signal being input to a serial I / F (interface) or the like.

  The flash ROM 36 holds programs (firmware) executed by the CPU 35 and setting data.

  FIG. 4 is a flowchart of a position detection process of the mobile wireless telephone 5 of the first embodiment. In this example, in order to perform movement detection (simple inertial navigation) based on an acceleration sensor, the processing of this flowchart is started at sufficiently fine intervals (10 ms to several hundreds of ms).

  First, in step S41, the CPU 15 of the mobile wireless telephone 5 takes in a signal (acceleration value) of the acceleration sensor 17.

  Next, in step S42, the CPU 15 calculates the integration of the taken-in acceleration value twice and calculates the position (the integrated movement distance from the initial position).

  Next, in step S43, the CPU 15 determines whether the moving distance exceeds the threshold or whether one minute or more has elapsed since the timer was started. If the moving distance exceeds the threshold or one minute or more has elapsed since the timer was started (Yes), the process proceeds to step S44, and the CPU 35 transmits some serial signal to the GPS / IMES receiver 16, etc. Wake up receiver 16; In addition, CPU15 may transmit the serial signal for starting by IMES priority acquisition (after-mentioned), when it shows that CS-ID currently used for position registration by PHS net | network is indoors. This serial signal may carry a reserved PRN number to be reserved.

  Next, in step S45, the CPU 35 of the GPS / IMES receiver 16 refers to the previous capture / tracking status held in the built-in RAM, and whether the IMES signal has been received last time or the IMES priority capture is specified Determine if it has been done. If the IMES signal has been received last time or if IMES priority acquisition is specified (Yes), the CPU 35 of the GPS / IMES receiver 16 outputs the determination result to the CPU 15. Then, the process transitions to step S46, and the CPU 15 performs position detection by IMES priority acquisition.

  In the IMES priority acquisition, when the IMES signal has been received last time, first, the IMES signal (any one of the PRN numbers 173 to 182) is acquired with the highest priority. If not captured or captured but the reception level is less than a predetermined value, the remaining 9 PRN codes associated with the PRN code specifying the previously captured IMES transmitter are used from other IMES transmitters Try to capture If that also fails, GPS acquisition will also start. The GPS / IMES receiver 16 outputs the positioning state to the CPU 15 every second until the IMES acquisition (position detection) or positioning is successful after the start of step S46. If it does not succeed within a predetermined time, it will time out. The CPU 15 calculates the position (latitude / longitude height) of the mobile wireless telephone 5 from the latitude / longitude height of the IMES transmitter whose reception level is equal to or more than a predetermined value. Then, the position represented by the calculated latitude and longitude is stored in the RAM 23 in association with the detection time and the PRN code.

  On the other hand, when it is judged as No by step S45, it changes to step S47 and CPU15 measures by GPS priority acquisition. In the GPS priority acquisition, if the GPS signal was acquired last time, the GPS signal is acquired again with the highest priority. If acquisition is not possible or the reception level is less than a predetermined value, acquisition from other GPS satellites (including quasi-zenith satellite etc.) that can be acquired based on ephemeris data is tried. If that also fails, IMES capture will also start. Also in step S47, if the position detection or the positioning does not succeed within the predetermined time, a timeout occurs.

  After step S46 or S47, in step S48, the CPU 15 causes the GPS / IMES receiver 16 to sleep by transmitting some serial signal to the GPS / IMES receiver 16. Alternatively, the GPS / IMES receiver 16 may sleep itself if positioning is successful.

  Finally, at step S49, the CPU 15 resets the integrated movement distance and starts the one-minute timer. In order to prevent accumulation of errors, the integration movement distance is at most one minute in the integration period. If the result of step S46 or S47 is a timeout (lost state), it may or may not be reset. In addition, the CPU 15 is based on the position information acquired last time and the movement distance calculated using the acceleration sensor 17 until one minute has passed since the GPS / IMES receiver 16 sleeps or the movement distance becomes equal to or more than a threshold. The position (latitude / longitude height) of the portable wireless telephone 5 is calculated. Then, the position represented by the calculated latitude and longitude is stored in the RAM 23 in association with the detection time and the PRN code.

  The above is the position detection processing of the portable radio telephone 5. However, if there is a change in the position or the detection processing started by the one-minute timer even if there is no change, then the position on the PHS network side Perform registration. As in the prior art, position detection every three seconds is not performed, so position registration every three seconds is completely meaningless (in terms of improving the position accuracy) and can be omitted.

FIG. 5 is a class diagram of the CS-IMES dictionary 51 held by the mobile wireless telephone 5.
The CS-IMES dictionary 51 stores an arbitrary number (including 0) of IMES objects 53 in association with each of the plurality of CS objects 52. One CS object 52 has one CS-ID as an attribute. One IMES object 53 has one PRN number as an attribute. Each of the IMES objects 53 is associated with an arbitrary number (including 0) of adjacent IMES objects 54. The PRN number attribute held by the adjacent IMES object 54 indicates the IMES transmitter installed at a location spatially close to the IMES transmitter indicated by the PRN number of the associated IMES object 53.

  In step S46, the CPU 15 refers to the adjacent IMES object 54 based on the current CS-ID and the IMES PRN number detected immediately before, and uses the read PRN number as the spare PRN number to the GPS / IMES receiver 16. hand over. Having received the spare PRN number, the CPU 35 attempts acquisition with that PRN number with the second priority.

  In step S46 etc., when receiving the IMES position detection result, the CPU 15 associates the PRN number with the CS-ID at that time and adds it to the CS-IMES dictionary 51 as the IMES object 53 (already in the dictionary). If the PRN is different from the previous one even though the CS-ID is the same as the previous one, then the IMES object 53 corresponding to the previous detected PRN is newly added with the adjacent IMES object 54 having the currently detected PRN as an attribute. Match (does not need to be linked if already linked).

  In this manner, by providing the CS-IMES dictionary 51 and predicting the next IMES transmitter that can be received by movement and attempting to capture at that PRN, capture can be performed in a short time, and power consumption is also reduced.

  According to the portable wireless telephone 5 of the first embodiment, the PRN code is provided with the acceleration sensor 17 for detecting the acceleration due to the movement of the own device, and for identifying the IMES transmitter each time the position information of the own device is detected. Is stored in the CS-IMES dictionary 51 in association with a PRN code (PRN number) specifying an adjacent IMES transmitter, and the CPU 15 calculates the movement distance of the own machine from the detection result of the acceleration sensor 17 , Determines whether the moving distance exceeds the threshold from the time when the GPS / IMES receiver 16 is off, turns on the GPS / IMES receiver 16 when the threshold is exceeded, and is stored in the CS-IMES dictionary 51 The PRN number is passed to the GPS / IMES receiver 16 so that the GPS / IMES receiver 16 detects the position of the own machine.

  Therefore, it is possible to extend the usable time of the portable radio telephone 5 by reducing the reception frequency of IMES and suppressing the power consumption while maintaining the position accuracy.

  Further, according to the portable wireless telephone 5 of the first embodiment, when the position information of the own device is detected by the GPS / IMES receiver 16, the GPS / IMES receiver 16 is turned off, and one minute is elapsed. Alternatively, it is possible to detect the position of the own machine by using the acceleration sensor 17 with the previous position detection result of the own machine as an initial position until the moving distance of the own machine obtained by the acceleration sensor 17 exceeds the threshold. The number of transmitters can be reduced. A geomagnetic sensor (electronic compass) is also provided, and if autonomous navigation is performed as in Patent Document 4, the current position can be updated and position registration can be performed on the network side without relying on position detection by IMES or GPS, and IMES transmitter Ground spacing can be reduced.

  In the second embodiment, an indoor wireless system provided with the mobile wireless telephone 5 of the first embodiment will be described.

FIG. 6 is a state transition diagram showing the position detection process of the mobile wireless telephone 5.
In the indoor radio system, the IMES transmitters 1, 2 in places where it is difficult to know the position or places where you want to increase the position accuracy locally, such as indoors where GPS radio waves do not reach or coverage areas where two base stations overlap. Arrange 2 The IMES transmitters 1 and 2 output position information indicating the installation position. The IMES transmitters 1 and 2 are weak radio waves whose upper limit value of output is about -94 dBW, and IMES areas 3 and 4 of about 10 m in which the communicable range is extremely smaller than the base station area are formed in the periphery.

  As described above, the portable radio telephone 5 includes the GPS / IMES receiver 16, receives radio waves transmitted from GPS satellites (not shown) or IMES transmitters 1 and 2, and acquires position information. Check the current position.

  The CPU 15 of the mobile wireless telephone 5 starts the positioning operation, and turns on the GPS / IMES receiver 16 first. At this time, in both capture modes, the GPS / IMES receiver 16 captures and follows GPS satellites (step S61), receives radio waves from the GPS satellites, acquires current position information, and outputs the information to the CPU 15. After acquiring the position information, the CPU 15 sets the GPS / IMES receiver 16 to the GPS ONLY mode (step S62), and turns off the GPS / IMES receiver 16.

  On the other hand, when the level of the radio wave from the GPS satellite drops below the predetermined value in the state set to the GPS ONLY mode, the CPU 15 can acquire other GPS satellites (including quasi-zenith satellite etc.) that can be acquired based on ephemeris data. Try to capture from, and if it also fails, set the GPS / IMES receiver 16 to both capture modes. At this time, the GPS / IMES receiver 16 captures and follows the IMES transmitters 1 and 2, receives radio waves from the IMES transmitters 1 and 2, acquires current position information, and outputs the information to the CPU 15. When acquiring the position information, the CPU 15 sets the GPS / IMES receiver 16 to the IMES ONLY mode (step S63) and turns off the GPS / IMES receiver 16.

  On the other hand, when the level of radio waves from IMES transmitters 1 and 2 falls below a predetermined value in the state of being set to IMES ONLY mode, CPU 15 stores the IMES data stored in CS-IMES dictionary 51 and captured last time Attempt acquisition from other IMES transmitters using the remaining PRN codes associated with the PRN code that identifies the aircraft, and if it also fails, set the GPS / IMES receiver 16 to both acquisition modes . At this time, the GPS / IMES receiver 16 captures and follows the GPS satellites, receives radio waves from the GPS satellites, acquires current position information, and outputs the information to the CPU 15.

  As described above, according to the second embodiment, as in the first embodiment, the reception frequency of IMES can be reduced while the positional accuracy is maintained, and the usable time of the mobile wireless telephone 5 can be extended by suppressing the power consumption. it can.

  In addition, the present invention is not limited to the above embodiment as it is, and at the implementation stage, the constituent elements can be modified and embodied without departing from the scope of the invention. In addition, various inventions can be formed by appropriate combinations of a plurality of components disclosed in the above embodiments. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, components in different embodiments may be combined as appropriate.

  1, 2 ... IMES transmitter, 3, 4 ... cover area, 5 ... mobile radio telephone, 11 ... RF unit, 12 ... L1 processing unit, 13 ... L2 processing unit, 14 ... ADPCM unit, 15 ... CPU, 16 ... GPS / IMES receiver, 17 ... acceleration sensor, 18 ... keypad, 19 ... key controller, 21 ... LCD controller, 22 ... ROM, 23 ... RAM, 24 ... timer, 31 ... RF front end, 32 ... A / D converter , 33: Capturer, 34: Tracker, 35: CPU, 36: Flash ROM, 51: CS-IMES Dictionary, 52: CS Object, 53: IMES Object, 54: Adjacent IMES Object.

Claims (3)

A mobile wireless telephone used as the terminal, in an indoor radio system including a plurality of IMES (Indoor Messaging System) transmitters, each of which constitutes a cover area, provided with a terminal located in the cover area,
The PRN code specifying the IMES transmitter to be captured is acquired from the radio waves transmitted from each of the plurality of IMES transmitters, and the radio wave transmitted from the IMES transmitter corresponding to the acquired PRN code is received Position detection means for detecting the position of the own terminal;
Acceleration detection means for detecting acceleration due to movement of the own terminal;
Storage means for storing a PRN code corresponding to the previously captured IMES transmitter when the position detection means is turned off;
The movement distance of the own terminal is obtained from the detection result of the acceleration detection means, and it is determined whether the movement distance of the own terminal exceeds a threshold from the time of turning off the position detection means. Control means for turning on the detection means and causing the position detection means to detect the position of the own terminal based on the PRN code stored in the storage means;
GPS / IMES receiving means for receiving radio waves transmitted from a GPS satellite or the IMES transmitter, acquiring position information, and confirming the current position ,
The control means turns on the GPS / IMES receiving means, captures and follows the GPS satellites in both acquisition modes, and the GPS / IMES receiving means receives radio waves from the GPS satellites and acquires current position information To the control means, and when the position information is obtained, the control means sets the GPS / IMES receiving means to the GPS ONLY mode and turns off the GPS / IMES receiving means,
The control means tries to capture the other GPS satellites based on ephemeris data when the level of the radio wave from the GPS satellites falls below a predetermined value in the state of being set to the GPS ONLY mode. If the GPS / IMES receiving means is set to both capture modes, the GPS / IMES receiving means captures and follows the IMES transmitter, receives radio waves from the IMES transmitter, and receives the current position. When information is obtained and output to the control means, the control means sets the GPS / IMES receiving means to the IMES ONLY mode and turns off the GPS / IMES receiving means when the current position information is obtained.
When the level of the radio wave from the IMES transmitter falls below a predetermined value while the IMES ONLY mode is set, the control means stores the IMES transmitter stored in the storage means and captured last time The acquisition of another IMES transmitter is attempted using the remaining PRN code associated with the PRN code to be specified, and when the acquisition fails, the GPS / IMES receiving means is set to both acquisition modes, A GPS / IMES receiving means captures and follows the GPS satellite, receives a radio wave from the GPS satellite, acquires current position information, and outputs the information to the control means .   The control means turns off the position detection means when position information of the own terminal is detected by the position detection means, and the movement distance of the own terminal obtained by the acceleration detection means until a predetermined time elapses 2. A portable radio telephone according to claim 1, wherein the position of the terminal is detected using the acceleration detecting means with the previous position detection result of the terminal as an initial position until the threshold value is exceeded. Multiple IMES (Indoor Messaging System) transmitters, each of which constitutes a coverage area,
A portable radio telephone located in a cover area formed by at least one IMES transmitter among the plurality of IMES transmitters;
The portable radio telephone
The PRN code specifying the IMES transmitter to be captured is acquired from the radio waves transmitted from each of the plurality of IMES transmitters, and the radio wave transmitted from the IMES transmitter corresponding to the acquired PRN code is received Position detection means for detecting the position of the own terminal;
Acceleration detection means for detecting acceleration due to movement of the own terminal;
Storage means for storing a PRN code corresponding to the previously captured IMES transmitter when the position detection means is turned off;
It is judged whether the movement distance of the own terminal obtained by the acceleration detection means exceeds the threshold from the time when the position detection means is off, and when the threshold is exceeded, the position detection means is turned on and acquired last time Control means for causing the position detection means to detect the position of the own terminal based on the PRN code stored in the storage means, when the position information is from the IMES transmitter ;
GPS / IMES receiving means for receiving radio waves transmitted from a GPS satellite or the IMES transmitter, acquiring position information, and confirming the current position;
Equipped with
The control means turns on the GPS / IMES receiving means, captures and follows the GPS satellites in both acquisition modes, and the GPS / IMES receiving means receives radio waves from the GPS satellites and acquires current position information To the control means, and when the position information is obtained, the control means sets the GPS / IMES receiving means to the GPS ONLY mode and turns off the GPS / IMES receiving means,
The control means tries to capture the other GPS satellites based on ephemeris data when the level of the radio wave from the GPS satellites falls below a predetermined value in the state of being set to the GPS ONLY mode. If the GPS / IMES receiving means is set to both capture modes, the GPS / IMES receiving means captures and follows the IMES transmitter, receives radio waves from the IMES transmitter, and receives the current position. When information is obtained and output to the control means, the control means sets the GPS / IMES receiving means to the IMES ONLY mode and turns off the GPS / IMES receiving means when the current position information is obtained.
When the level of the radio wave from the IMES transmitter falls below a predetermined value while the IMES ONLY mode is set, the control means stores the IMES transmitter stored in the storage means and captured last time The acquisition of another IMES transmitter is attempted using the remaining PRN code associated with the PRN code to be specified, and when the acquisition fails, the GPS / IMES receiving means is set to both acquisition modes, A premises wireless system characterized in that the GPS / IMES receiving means captures and follows the GPS satellites, receives radio waves from the GPS satellites, acquires current position information, and outputs the information to the control means .