JP5023508B2 - Wireless positioning system, wireless positioning method, and program for wireless positioning - Google Patents

Description

The present invention relates to a radio positioning system, a radio positioning method, and a program for radio positioning, and more particularly, to a radio positioning system , a radio positioning method, and a program for radio positioning suitable for use in detecting the position of a mobile terminal.

  As a positioning method for detecting the position of a mobile terminal, a time difference (hereinafter referred to as TDOA: Time) in which radio waves transmitted from a plurality of base stations (satellites) reach the mobile terminal, such as GPS (Global Positioning System). There is a method using the Difference of Arrival).

FIG. 1 shows a principle diagram of TDOA. In FIG. 1, 101 is a base station A, 102 is a base station B, 103 is a base station C, 104 is a base station D, 105 is a mobile terminal M, 106 is a hyperbola, and 107 is a hyperbola. The distances from the mobile terminal M105 to the base station A101, base station B102, and base station C103 are _denoted by r _a , r _b , and rc, respectively. When the distance difference (r _a −r _b ) is obtained, a hyperbola 106 that focuses on the base station A 101 and the base station B 102 can be drawn. Similarly, when the distance difference (r _a −r _c ) is obtained, a hyperbola 107 focusing on the base station A 101 and the base station C 103 can be drawn. The intersection of the two hyperbolas 106 and 107 becomes the mobile terminal M105. Telecommunications the distance _{r a, r b, r c} is the radio waves transmitted simultaneously from the mobile terminal M105 has a base station A101, a base station B 102, using the time received at the base station C103, propagated through the distance The delay time is obtained. The distance difference (r _a −r _b ) is obtained by the difference in delay time from the mobile terminal M105 to the base station A101 and from the mobile terminal M105 to the base station B102, and from the mobile terminal M105 to the base station A101, the mobile terminal M105 The distance difference (r _a −r _c ) is obtained from the difference in the delay time from to the base station C103.

In order to detect the position of the mobile terminal M105 by the TDOA method, the arrival time difference can be obtained on the mobile terminal side if the timing of transmitting radio waves from a plurality of base stations coincides or is fixed. For that purpose, each base station needs to be time-synchronized.

  In GPS, since the atomic clock is mounted on each satellite, the time lag is small, but since the atomic clocks of the satellites are not synchronized, they are shifted little by little. Therefore, the method shown in FIG. 2 is adopted.

  In FIG. 2, 201 is a satellite A, 202 is a satellite B, 203 is a satellite C, 204 is a ground control station, 205 is a ground mobile terminal, <1> is a GPS signal reception, and <2> is a satellite clock correction value. Calculation, <3> indicates a step of transmitting correction value satellite, and <4> indicates a step of transmitting correction value data.

  The ground control station 205 receives the GPS signal in step <1>, performs correction calculation of the clock of each satellite in step <2>, monitors the clock deviation of each satellite, and transmits to each satellite in step <3>. A synchronization method is used in which a correction value is sent and time correction information is transmitted from each satellite in a navigation message and transmitted to the mobile terminal 205 in step <4>.

  In addition, as a conventional technique, for the purpose of positioning a mobile terminal (mobile phone), a pseudo base station for correcting cable delays in each base station and between base stations is provided, and a synchronization clock is generated using a GPS signal. The time of each base station is synchronized with the generated clock (see Patent Document 1).

  In addition, there is a method in which the base stations are connected by wire or wireless to synchronize the clocks of the base stations (see Patent Document 2). However, the wired connection requires time and labor for laying the cable, resulting in high costs.

In addition, in order to synchronize the clock wirelessly, it is necessary to extract the clock from the wireless signal and synchronize the clock of the local station, which complicates the circuit. In addition, since the synchronization signal is always transmitted wirelessly, a dedicated radio channel for the synchronization signal is required.
JP 2003-28943 A JP 2002-31675 A

  When a radio positioning system corresponding to the GPS is constructed on the ground, if the same time synchronization method as that of the GPS is used, a dedicated communication channel that is originally unnecessary is required between the control station and each base station. Since the clock deviation of all the base stations is managed, the operation of the control station becomes complicated, and if there are many base stations, the control of the control station will not be in time for the positioning cycle of each mobile terminal.

  In addition, a method of generating a synchronization clock using a GPS signal and synchronizing each base station has a synchronization clock accuracy of about several tens of nsec from the GPS signal, and about 1 nsec when accuracy of 1 m or less is required. Therefore, the accuracy of 1 m or less cannot be realized with the clock from the GPS signal.

  In addition, in order to improve time accuracy, a stable synchronization signal equivalent to GPS is generated and transmitted to each base station to form a similar system. However, different radio waves are used for synchronization signal transmission and positioning signal transmission. Is required, and the system is complicated and expensive.

  Accordingly, one of the objects of the present invention is to provide a radio positioning apparatus, a radio positioning method, and a program for radio positioning that accurately detect the position of a mobile terminal.

  The present invention is not limited to the above-mentioned object, and is a result derived from each configuration shown in the best mode for carrying out the invention described later, and has an effect that cannot be obtained by conventional techniques. It can be positioned as one of the purposes.

(1) In the present invention,
A radio positioning system that determines the position coordinates of a mobile terminal by transmitting positioning signal pulses from at least three base stations,
The base station includes one master base station and a plurality of slave base stations,
The main base station is
Transmitting means for transmitting a synchronization signal pulse to the slave base station ;
Means for transmitting a first positioning signal pulse to the mobile terminal at a time obtained by adding a predetermined time to the transmission time of the synchronization signal pulse;
The slave base station is
The determination of the reception time of the synchronizing signal pulses, with reference to the reference clock, wherein the slave base station is provided, a crude timer operates at the reference clock is performed with a precision timer operating in finer increments than the reference clock ,
Means for measuring a time difference T _fb between the reception time of the synchronization signal pulse transmitted from the master base station and the reference clock of the slave base station;
Means for obtaining a clock shift time _Tob between a reference clock of the master base station and a reference clock of the slave base station from the shift time T _fb and a preset delay time T _pb ;
The time obtained by adding the delay times T _ob of the clock to the transmission time of the first positioning signal of the main base station, and means for transmitting the second positioning signal pulse and shift time T _ob of the clock to the mobile terminal Prepared,
The mobile terminal
Means for correcting using the shift time T _ob of said time of receiving said second positioning signal pulse clock,
Using the time when the first positioning signal pulse is received and the time when the corrected second positioning signal pulse is received, and the position coordinates of the master base station and the slave base station stored in the mobile terminal, Means for determining the position coordinates of the mobile terminal;
A wireless positioning system characterized by comprising:

Preferably, the base station, the transmission of the first positioning signal pulse to said mobile terminal, using a radio positioning system according to claim 1, further comprising a means for repeating a predetermined cycle.

Good Mashiku, said base station, said first positioning signal pulse to be transmitted to the mobile terminal, temporally in the second positioning signal pulses the mobile terminal from the main base station and the subordinate base station heavy The wireless positioning system according to claim 1 , comprising means for transmitting at a predetermined time with a time difference that does not overlap, and means for transmitting data of the time difference that does not overlap in time to the mobile terminal. Use.

Preferably, the base station, the transmission of the positioning signal pulses carried by temporally non-overlapping time difference, the transmission of data of said time difference, according to claim 1, characterized in that it comprises means for repeated at a predetermined cycle Using a wireless positioning system .

Preferably, the slave base station, the determination of the time for transmitting the second positioning signal pulses with a time difference that does not overlap with the time, based on said reference clock said slave base station with the reference clock in said coarse timer operates, the radio positioning system according to claim 1, wherein a carried out using the precision timer operating in finer increments than the reference clock is used.

2. The radio positioning system according to claim 1 , wherein the main base station includes means for transmitting the first positioning signal pulse having the function of the synchronization signal pulse.

Preferably, the main base station, according to claim 1, characterized in that the transmission to the mobile terminal having a function of the sync signal pulse of the first positioning signal pulses, comprising means for repeating a predetermined cycle The described wireless positioning system is used.

Preferably, the base station, a predetermined pseudo-random digital signal, and impulse-at a particular position of the device and the pulse position modulated chip width of the pseudorandom digital signal pulse position modulation by any digital signal super 2. The wireless positioning according to claim 1 , further comprising: means for generating a broadband wireless signal; and means for transmitting a positioning signal pulse having the synchronization function by the impulsed ultra-wideband wireless signal. Use the system .

Preferably, the slave base station received from the main base station, the determination of the reception time of having the synchronization function the second positioning signal pulse, based on said reference clock said slave base station with , using the rough timer and a radio positioning system according to claim 1, characterized in that using the precision timer operating in finer increments than the reference clock running at the reference clock.

(2) In addition, the base station uses the wireless positioning system according to claim 1 , wherein the base station transmits an impulsed ultra-wideband wireless signal.

Preferably, the base station transmits a predetermined pseudo-random digital signal is pulse position modulated by any of the digital signal, the impulse signal at a particular position of the tip width of the pulse position modulated pseudo-random digital signal The wireless positioning system according to claim 1 is used.

Preferably, the base station, as a pseudo-random digital signal for generating, using a radio positioning system according to claim 1, characterized by using the pulse position modulated signal by Reed-Solomon code.

Preferably, the base station uses a radio positioning system according to claim 1, further comprising a means for band-limiting impulse-signal transmitted in a predetermined band-pass filter.

Preferably, the slave base station, the determination of the reception time of the sync pulse, and the signal in which the slave base station detects received, the same pseudo-random digital signal and the main base station the slave base station is provided with The wireless positioning system base station according to claim 1 , further comprising means for performing time comparison based on correlation between the two.
(3) Further, the mobile terminal uses the time offset T _ob of the clock received from the slave base station, further comprising: a first means for compensation a time of receiving the second positioning signal pulse the use of radio positioning system according to claim 1, wherein you characterized.
Preferably, the mobile terminal, the position coordinates of the mobile terminal determined by the mobile terminal, the user of certain other mobile terminals identified, and means for transmitting through even one less of the base station The wireless positioning system according to claim 1 , further comprising: means for transmitting to a user of the identified specific fixed terminal via a network connected to the base station.

Preferably, the mobile terminal, the first from the slave base station and the main base station, the determination of the reception time of the second positioning signal pulse, a signal which the mobile terminal has detected received, to the mobile terminal 2. The radio positioning system according to claim 1, further comprising means for performing time comparison by correlation between the main base station and the pseudo-random digital signal unique to the slave base station.

Preferably, the mobile terminal, using the data of the time difference does not overlap with the time, the position coordinates of the mobile terminal determined by the mobile terminal, the user of certain other mobile terminals identified, the claim that the means for transmitting the base station at least through one, characterized in that the user of a particular fixed terminal identified and and means for transmitting via a network connected to the base station 1 is used.

Preferably, the mobile terminal uses the data of the temporally non-overlapping time difference at said mobile terminal received from the base station, the time of reception of the positioning signal pulse from the base station, means for correcting a predetermined cycle The wireless positioning system according to claim 1 is used.

Preferably, the mobile terminal, the first sent by the time difference from the base station, the determination of the reception time of the second positioning signal pulse, a signal which the mobile terminal has detected received, provided to the mobile terminal And means for performing time comparison by correlation with a pseudo-random digital signal common to each base station, and means for correcting the reception time of the positioning signal pulse with time difference data received from the base station. The wireless positioning system according to claim 1 is used.

Preferably, the mobile terminal, the first having the function of the sync pulse, the position coordinates of the second positioning signal pulse the mobile terminal which is determined using the reception time of the identified specific other was Means for communicating to a user of a mobile terminal via at least one of the base stations, and means for communicating to a user of a specific identified fixed terminal via a network connected to the base station. preferably using wireless positioning system of claim 1, wherein the said mobile terminal, said having a function of synchronizing signal pulses first, the time of receiving the second positioning signal pulse, the base station The wireless positioning system according to claim 1, further comprising means for correcting at a predetermined cycle using time difference data received from.

Preferably, the mobile terminal, the first having the function of the synchronization signal pulses received from the base station, the determination of the reception time of the second positioning signal pulse, a signal which the mobile terminal has detected the received 2. The radio positioning system according to claim 1, wherein the radio positioning system is used by time comparison based on a correlation with a pseudo-random digital signal common to the base station provided in the mobile terminal. (4) In the present invention, a radio positioning method for determining a position coordinate of a mobile terminal by transmitting positioning signal pulses from at least three base stations, wherein the base station includes one main base station and a plurality of base stations. includes a slave base station, the main base station, sending a synchronizing signal pulse to the slave base station, the time obtained by adding a predetermined time to the transmission time of the sync pulse, the first positioning to the mobile terminal Transmitting a signal pulse, the slave base station determining the reception time of the synchronization signal pulse, a coarse timer operating with the reference clock with reference to a reference clock provided in the slave base station, and the reference A step performed using a precision timer that operates in finer steps than the clock, and a time difference T _f between the reception time of the synchronization signal pulse transmitted from the master base station and the reference clock of the slave base station _b from the step of measuring _b , the deviation time T _fb and the preset delay time T _pb , the deviation time T _ob of the clock between the reference clock of the master base station and the reference clock of the slave base station a step of obtaining the transmission time plus the delay times T _ob of the clock to the transmission time of the first positioning signal of the main base station, the second positioning signal pulse and shift time T _ob of the clock to the mobile terminal a step of the mobile terminal, and correcting by using the shift time T _ob of said time of receiving said second positioning signal pulse clock, time and the corrected received the first positioning signal pulse using the time of reception of the second positioning signal pulses, the position coordinates of the main base station and the subordinate base station stored in the mobile terminal, the scan for determining the position coordinates of the mobile terminal Tsu using a wireless positioning method including a flop, the.
(5) In the present invention, radio positioning is performed in which a synchronization signal pulse is transmitted from one master base station to a plurality of slave base stations, and the slave base station determines a transmission time of a positioning signal pulse to be transmitted to a mobile terminal. For transmitting the first positioning signal pulse from the synchronization signal pulse transmission end time in the main base station notified in advance from the main base station. time and T _a until the start time, and the positioning signal pulse in advance and we know they were propagation delay time measurement of T _pi from the main base station to the slave base stations, and pre-measured minute
And the shift time T _0i of the slave base station in response to of had bought the main base station clock clock,
By means of inputting the clock period T _k in the main base station previously notified from the main base station, addition / subtraction, calculation of the integer part of division, and multiplication,
T _i = {(T _a −T _pi + T _0i ) divT _k } × T _k
And means for outputting the calculation result T _i as a time difference from the time when the slave base station receives the synchronization signal pulse of the master base station to the time when the positioning signal pulse is transmitted. , Use a program for wireless positioning to function as.

  According to the present invention, the time coordinates of a plurality of base stations can be accurately adjusted, so that the position coordinates of the mobile terminal can be determined accurately.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

In this embodiment, a synchronization signal is broadcast from one base station that also serves as a reference station to at least two other base stations, and the other two base stations receive the time of the received synchronization signal. Then, each of the timers of the own station is measured, and a correction value of the deviation is transmitted on the data signal to the mobile terminal, and the mobile terminal determines the reception time of the positioning signal transmitted from each base station by the correction value. It correct | amends and detects the position of this mobile terminal.
"Communication route configuration of wireless positioning system of Example 1"
FIG. 3 shows the basic communication route configuration of the wireless positioning system in this embodiment, and FIG. 4 shows the actual communication route configuration.

  In FIG. 3, 301 is a reference station, 302 is a base station B, 303 is a base station C, 304 is a base station D, 305 is a mobile terminal M, <1> is a synchronization signal transmission, and <2> is a synchronization signal reception. , <3> represents a self-clock correction value calculation, and <4> represents a correction value data transmission step.

  4, the same components as those in FIG. 3 are given the same numbers, 401 indicates the base station A, <1> is the base station A reception, <2> is the self-clock correction value calculation, <3> Indicates steps of correction value data transmission.

  As shown in FIG. 3, in this embodiment, a time reference station 301 is defined, and a synchronization radio wave from the reference station 301 is transmitted to another base station in step <1>. In each base station, the delay between the reference station 301 and each base station is obtained in advance, and each base station uses the reception time of the synchronization radio wave from the reference station 301 in step <2>, and the own station in step <3>. You can see the difference of the clock. In step <4>, the correction value data of the own station is placed on the positioning radio wave transmitted from each base station to the mobile terminal 305. The mobile terminal 305 can obtain an accurate arrival time difference by receiving the correction data and correcting the clock deviation of the positioning radio wave from each base station.

  In FIG. 4, when the base station A401 also serves as the reference station 301, and the positioning signal and the synchronization signal from the base station A401 are transmitted on the same radio wave in step <1>, the reference station 301 and the base station 401 are The number of stations can be reduced because there is no need to separate the stations. Further, it is not necessary to send the synchronization signal and the positioning signal with different radio waves, and the circuit is simplified. In step <2>, each base station that has received the synchronization signal calculates its own clock. In step <3>, the base station transmits the positioning radio wave transmitted from each base station to the mobile terminal 305. Put data.

  In the present embodiment, an impulse radio wave (UWB-IR) is used as the radio wave, so that the arrival time of the radio wave can be obtained with high accuracy, and the positioning accuracy is improved. In order to perform positioning with an accuracy of about 30 cm, a time accuracy of about 1 nsec is required. If an arrival time is to be obtained by a clock counter, a high-speed operation of 1 GHz or more is required, which cannot be realized with an inexpensive circuit.

In this embodiment, the clock counter is operated at about 100 MHz (period 10 nsec) (hereinafter referred to as “rough timer”), and the delay of the circuit is used for steps of 10 nsec or less so that it can be easily realized with a normal CMOS circuit. Measure with a timer (hereinafter referred to as precision timer). Since it is easy to synchronize with the value of the coarse timer, each base station first synchronizes the signal extracted from the received synchronization signal with the value of the coarse timer, and then uses the value of the fine timer as the correction value. As a result, the accuracy of the correction data of the reception time can be improved.
・ "Device configuration and operation of the wireless positioning system of the first embodiment"
FIG. 5 shows a block diagram of the base station A in this embodiment, FIG. 6 shows a block diagram of the base station B, and FIG. 7 shows a transmission data format.

  In FIG. 5, 501 is an MPU (microprocessor unit), 502 is transmission data, 503 is a PPM (pulse position modulation) data modulation unit, 504 is a PN sequence generation unit, 505 is a reference clock, 506 is an impulse generation unit, and 507 is A transmission BPF (bandpass filter), 508 indicates a PA (power amplifier), and 509 indicates a transmission antenna.

  In FIG. 6, 601 is an MPU (microprocessor unit), 602 is transmission data, 603 is a PPM (pulse position modulation) data modulation unit, 604 is a PN sequence generation unit, 605 is a period timer, 606 is an impulse generation unit, and 607 is Transmit BPF (band pass filter), 608 PA (power amplifier), 609 transmit antenna, 610 reference clock, 611 receive antenna, 612 receive BPF (band pass filter), 613 LNA (low noise amplifier), Reference numeral 614 denotes a pulse detector, 615 denotes a precision timer, 616 denotes a correlator, 617 denotes a latch, and 618 denotes a PN sequence generator.

  In FIG. 7, D701 indicates a preamble part (no modulation), D702 indicates a data part (PPM modulation), 711 indicates position hopping for one chip, and 712 indicates position hopping for one chip.

"Operation of base station A of the first embodiment"
The transmission operation in the base station A501 will be described with reference to FIGS.

  The first part of the transmission data 502 is a section of the preamble D701, and the transmission data 502 transmitted from the MPU 501 is a pulse of 1 pulse 1 μsec, but in the preamble D701, all of the sections of 7 pulses 7 μsec are 0.

  In FIG. 5, the PPM data modulation unit 503 does not change the time position of the pulse chip input from the PN sequence generation unit 504 when the transmission data 502 sent from the MPU 501 is 0, but changes by 1 chip when the transmission data 502 is 1. Performs (hopping) pulse position modulation.

  The PN sequence generation unit 504 generates an 8-level RS (Reed-Solomon) sequence code sequence, which is a kind of PN sequence, and generates a pulse of 100 nsec per chip corresponding to the generated code every 1 μsec period. Generate a pulse waveform placed in For example, corresponding to the code of 576421, a pulse of 100 nsec is positioned at 500 nsec in the first 1 μs interval for the first 5 and 700 nsec in the next 1 μsec interval for the next 7; This is a waveform arranged at a position corresponding to.

  Also, the transmission data 502 sent from the MPU 501 shown in FIG. 5 is a 1 μsec pulse combination code, and is composed of a preamble portion D701 at the beginning of the transmission data in FIG. 7 and a data portion D702 following this.

  In the preamble part D701 in FIG. 7, the transmission data 502 is all zero in one cycle of 7 μsec. At this time, in the PPM data modulation unit 503, since the modulation inputs are all 0, the pulse position of the pattern waveform from the PN sequence generation unit 504 is output as it is, and the pulse shown in the preamble portion D701 of FIG. It becomes a signal waveform.

  The data part D702 follows the preamble part D701.

  In the data part D702, the transmission data has an arbitrary code within a predetermined period. For example, when the transmission data is 0110..., The PPM data modulation unit 503 causes the pulse position of the chip to be 0110 due to the pattern waveform 576421 (more than 7 signs of the normal preamble part) from the PN sequence generation unit 504. .. Corresponding to... Hopping by 1 chip (indicated by 711, 712 in FIG. 7), modulated as 5873..., And hopped to positions of 500 nsec, 800 nsec, 700 nsec, 300 nsec. The pulse signal waveform shown in the data portion D702 of FIG.

  In FIG. 5, the PPM-modulated pulse signal is sent to the impulse generator 506, and a very thin impulse is generated at the rising edge of the pulse by the step recovery diode. The generated impulse has a very wide frequency band spectrum, but it is allowed to pass through BPF507 (a bandpass filter, for example, a passband of 3.1 GHz to 10.6 GHz). Outside (for example, 3.1 GHz or less and 10.6 GHz or more) spectral components can be removed. After passing through the BPF, it is amplified by a PA 508 (power amplifier), and a radio wave is radiated from the transmitting antenna 509.

"Operation of base station B of embodiment 1"
The transmission operation of the base station B302 is the same as that of the base station A.

  The reception operation of the base station B302 will be described with reference to FIGS.

  The impulse radio wave received from the antenna 611 of the base station B302 is subjected to low frequency amplification by the LNA 613 after unnecessary frequency components are removed by the BPF 612, and the pulse signal waveform is detected by the pulse detection unit 614. The pulse detection unit 614 is realized by an envelope detection circuit using a high-frequency diode, a comparator, and the like. The detected pulse is compared with the RS sequence code string generated by the PN sequence generator 618 by a correlator 616 using a digital matched filter. If the preamble part D701 is detected by the correlator 616, assuming that synchronization is established, the reception time of the first pulse of the data part D702 that follows is held, and the received PPM signal of the data part D702 is demodulated.

  The determination of the reception time in the base station B302 will be described with reference to FIGS.

  In FIG. 8, 800 is an input signal, 811 is a first delay circuit, 812 is a second delay circuit, 813 is a third delay circuit, 814 is a fourth delay circuit, 819 is a ninth delay circuit, 820 Is DFF (Delay Flip Flop), 830 is output of delay 0, 831 is output of delay 1, 832 is output of delay 2, 833 is output of delay 3, 834 is output of delay 4, 839 is output of delay 9 Represent each.

  In FIG. 9, reference numerals 901, 902, and 903 denote times when the encoded values are latched by the coarse timer, D901 denotes a DFF input waveform, and D902 denotes a DFF output.

  In FIG. 8, an input signal 800 is a waveform obtained by latching the received impulse waveform detected by the pulse detection unit of FIG. The delay circuit 811 delays the input signal 800 by 1 nsec and outputs the delayed signal to the DFF 820 and the next delay circuit 812. The delay circuit 812 further delays the signal input from the delay circuit 811 by 1 nsec, and outputs the delayed signal to the DFF 820 and the next delay circuit 813. Thereafter, the delay circuit 814... Delay circuit 819 delays each by 1 nsec in the same manner as described above, and outputs it to the DFF 820.

  In FIG. 9, D901 indicates a signal with a delay of 0 and a total of 10 data output from the 9 delay circuits. The DFF 820 is composed of 10 DFFs that operate with a clock of 100 MHz, and the 10 input data is 0 or 1 at time 901, time 902, time 903. Is latched. The intervals of time 901, time 902, time 903,... Are 10 nsec, and will be referred to as a coarse timer.

  An input signal 800 shown in FIG. 8 represents a signal having a fraction of 5.5 nsec with respect to a coarse timer period of 10 nsec. Since the input data to the DFF 820 is data delayed by 1 nsec step by 10 delay circuits (hereinafter referred to as an encoded value), it has a waveform indicated by D901 in FIG. For example, the case where the delay of the input signal 800 is 5.4 nsec is shown in D902 of FIG. 9, the output of the DFF 820 corresponding to the delay circuit 4 from the delay circuit 1 becomes 1, and the output after the output of the DFF 820 corresponding to the delay circuit 5 is 01. Thus, the time in units of 1 nsec is determined to be 5 nsec. That is, the delay time of the input signal is determined by the number of the first delay circuit in which the output of the DFF 820 changes from 1 to 0. With this method, the circuit shown in FIG. 8 can determine a precise time in units of 1 nsec from a coarse timer of 10 nsec.

-"Method for correcting reception time of base station B in the first embodiment"
A timing correction method in the base station B will be described with reference to FIG.

  For simplicity, it will be described as a single pulse.

In FIG. 10, 1000 is a synchronization signal pulse P _as , 1001 is a positioning signal pulse P _ar , 1002 is a synchronization signal pulse P _bs , 1003 is a positioning signal pulse P _br , D101 is a synchronization signal interval, D102 is a positioning signal interval, D103 is Each of the synchronization signal sections is shown.

When the base station A401 transmits the synchronization signal P _as 1000, the base station B302 receives the synchronization signal _Pbs 1002 after a delay T _pb between the base station A401 and the base station B302. It is assumed that the delay time T _pb is known in advance by measurement. Both the base station A401 and the base station B302 are operating with a coarse clock (repetition frequency = 100 MHz, period T _k = 10 nsec). However, since the base station A401 and the base station B302 are not synchronized, the clock is T _0b time shift. If the time at which the synchronization signal from the base station A401 is received by the base station B302 is counted by the timer of the base station B302 and is measured with a deviation of T _{fb from} the coarse clock,

However, mod indicates the deviation of the timer of the base station B from the base station A by the remainder calculation / expression.

For example, when T _pb = 104 nsec and T _fb = 3 nsec, T _0b = (104-3) mod 10 = 1, and it can be seen that the difference T _0b between the precision timers of the base station A 401 and the base station B 302 is 1 nsec.

The base station A401, transmits sync signal pulse _P the as 1000 after sending a positioning signal _P ar 1001 after _{T a} time. The base station B302, a sync pulse _P bs 1002 after receiving, transmitting a positioning signal pulse _P br 1003 from the next clock after _{T b} Time. _Tb is obtained by equation (2).

However, div is an integer part of division, for example, when T _a = 1000 nsec, T _pb = 104 nsec, and T _0b = 1 nsec, T _b = {(1000−104 + 1 1) div10} × 10 = 890. P _ar 1001 and _P br 1003, because the clock is shifted, can not be issued at the same _time, P br 1003 is transmitted shift time by _{T 0b} against _P ar 1001. This clock shift _T0b is carried as data on the positioning signal D103 from the base station B302 and transmitted to the mobile terminal M305.

In the above description, it is assumed that a single pulse is transmitted from each station. However, since a plurality of signal pulse trains are actually transmitted from each station, a description will be given below.
"Signal transmission and reception timing at each station in the first embodiment"
FIG. 11 shows signal transmission and reception timing in each station.

In FIG. 11, 1101 is a synchronization signal transmission, 1102 is a synchronization reference pulse transmission time _tsa , 1103 is a positioning signal A transmission, 1104 is a reference pulse A transmission time _tta , 1105 is a base station A data transmission, and 1106 is a synchronization signal reception. 1107 is a synchronization reference pulse reception time t _sb , 1108 is a positioning signal B transmission, 1109 is a reference pulse B transmission time t _tb , 1110 is a base station B data transmission, 1111 is a synchronization signal reception, 1112 is a positioning signal A reception, and 1113 Is a positioning signal B reception, 1114 is a reference pulse A reception time _tr , 1115 is a reference pulse B reception time _trb , 1116 is base station A data reception, and 1117 is base station B data reception.

A synchronization signal pulse train 1101 is transmitted from the base station A 401, and the position t _sa 1102 of the first pulse after the preamble is used as a time reference. The base station B302 receives the reference pulse at time t _sb 1107 after T _pb time. The base station A401, a pulse train of positioning signals A1103 is transmitted to the reference pulse transmission after _{T a.}

The base station B302, after receiving the reference pulse at time _t sb 1107, after clock synchronization _{T b,} the positioning signal B pulse train 1108 is transmitted. The positioning signal A pulse 1103 and the positioning signal B pulse 1108 are shifted by T _0b , the time t _ta 1104 of the reference pulse after the preamble of the positioning signal A transmission 1103 of the base station A 401, and the positioning signal B transmission 1108 of the base station B 302 The time t _tb 1409 of the reference pulse after the preamble is also shifted by T _0b .

The reference pulse of the positioning signal A pulse train 1103 arrives at the mobile terminal M305 at a time _tra 1114 after T _ma from the transmission time t _ta 1104, and the reference pulse of the positioning signal B pulse train 1108 is transmitted from the transmission time t _tb 1109 to T _mb. It arrives at the mobile terminal M305 at a later time t _rb 1115. In the mobile terminal _M305, by measuring the time of t ra 1114 and _t rb 1115, determine the arrival time difference.

  Since the positioning signals transmitted from the base station A 305 and the base station B 302 overlap with each other, the synchronization signal pulse trains are distinguished by using different pseudo-random code sequences (hereinafter referred to as PN sequences).

If the preamble in the synchronization signal reception 1106 is detected by the correlator 616 of the receiving unit of the base station B302 in FIG. 6 and the reference pulse is detected, the value t _sb 1107 of the precise timer at that time is latched and stored in the MPU 601. It is captured. MPU601 from that point, (2) performs an operation of _{T b} by equation a post _{T b} measured at cycle timer -605, at that time, transmission of the positioning signal pulse train 1108 is started.

Also, the clock shift T _0b between the base station A 401 and the base station B 302 is calculated by the equation (1) in the MPU 601 and sent to the mobile terminal M 305 as correction value transmission data.

Note that the time position t _sb 1107 of the reference pulse received by the base station B302 is shifted because the first pulse position is hopped by the PN sequence, so that the hopping value is corrected with respect to the arrival time.

“Determining Arrival Time Difference and Position Coordinate in Mobile Terminal of First Embodiment”
The mobile terminal M305 in FIG. 4 obtains the arrival time difference of positioning signal radio waves from each base station. For example, the base station A401 and the base station B302 do not output positioning signals at the same time, and are shifted by _T0b. Therefore, T _0b is subtracted from the arrival time difference obtained by the mobile terminal M305 and corrected.

  The operation of the mobile terminal M305 will be described with reference to FIG.

  In FIG. 12, 1201 is an MPU (microprocessor unit), 1202a is a reception block A, 1202b is a reception block B, 1202c is a reception block C, 1203 is a latch, 1204 is a latch, 1205 is a PN sequence generation unit, and 1206 is reception data. 1207 is a PPM data demodulator, 1208 is a correlator, 1209 is a reference clock, 1210 is a coarse timer, 1211 is a fine timer, 1212 is a pulse detector, 1213 is an LNA (low noise amplifier), 1214 is a received BPF (bandpass) Reference numeral 1215 denotes a receiving antenna.

  The mobile terminal M305 has reception blocks as many as the number of base stations, and can receive a pulse signal from a plurality of base stations at the same time.

  When the pulse signal is received, the edge of the pulse is measured by the coarse timer 1210 and the fine timer 1211 and input to the correlator 1208 of each reception block. Since a different PN sequence is assigned to each base station, the correlator 1208 performs a correlation operation according to each PN sequence.

  The reception block A1202a detects a pulse signal from the base station A401. If the preamble of the synchronization signal pulse train from the base station A 401 is detected, the value of the fine timer and the value of the coarse timer are latched with the first reference pulse after the preamble and input to the MPU 1201. Further, the data transmitted from the base station A 401 is PPM demodulated by the PPM data demodulator 1207 and input to the MPU 1201. The operations of the coarse timer 1210 and the fine timer-1211 are the same as those in the base station B302 described with reference to FIGS.

  The MPU 1201 performs positioning calculation by determining the arrival time difference using the input arrival time of the pulses from each base station. The position coordinates of each base station are put on the transmission data from each base station and notified to the mobile terminal M305.

In the MPU 1201, the arrival time t _ra 1114 of the positioning signal pulse of the base station A is obtained from the values notified from the coarse timer 1210 and the fine timer 1211 of the reception block A 1202a. Also, the arrival time t _rb 1115 is obtained from the value of the coarse timer and the value of the fine timer from the reception block B. Further, since the arrival time t _rb 1115 is shifted by T _0b , the equation (3) is used. Make corrections.

A value _trb0 corrected by the equation (3) indicates an accurate arrival time.
The base station C304, to the base station A401, using said deviation _{T 0c} of _{T 0b} and transmission time calculated in the same manner, is corrected arrival time _{t rc0} sought, the equation (4).

  A method for determining the position of the mobile terminal M305 will be described with reference to FIG.

In FIG. 13, the same components as those in FIG. 4 are given the same numbers. The position coordinates of the base station A 401, base station B 302, base station C 303 and mobile terminal M 305 are respectively (x _a , y _a ), (x _b , y _b ), (x _c , y _c ), (x _m , y _m) and then, from each mobile terminal M305, the base station A301, a base station B302, a distance to the base station _C303, and _{r a, r b, r c} .

  The relationship between each coordinate and distance is

Further, the mobile terminal M305, the distance difference _{d ab} = _r a -r _b to the base station B302 to the base station A301, if the velocity of light is _c, since a _{d ab = c (t ra -t} rb0) , _Rb is given by equation (8).

Similarly, since the distance difference d _ac = r _a −r _c from the mobile terminal M305 to the base station A301 and the base station C303 is d _ac = c (t _ra −t _rc0 ), r _c is (9 ).

(8), the _r b, _{r c} by (9), (6), by substituting the equation (7),
(5), (6), (7) from the equation, the unknowns x _m, y _m, expression of matrix representing simultaneous equations containing _{r a} (10) is obtained.

However, A is a matrix of 2 rows and 2 columns, and each element is
_{a 11 = 2 (x b -x} a) a 12 = 2 (y b -y a)
_{a 21 = 2 (x c -x} a) a 22 = 2 (y c -y a)
B is a matrix with 2 rows and 1 column.
_{b 1 = 2c (t ra -t} rb0)
b ₂ = 2c ( _tra −t _rc0 )
C is a matrix with 2 rows and 1 column.
^{_{c 1 = -x a 2 + x}} b 2 -y a 2 + y b 2 -c 2 (t ra -t rb0) 2
c ₂ = −x _a ² + x _c ² −y _a ² + y _c ² −c ² ( _tra −t _rc0 ) ²
When x _{m and} y _m are obtained from the equation (10) under the condition of detA ≠ 0, the equation (11) is obtained using the inverse matrix A ⁻¹ of A.

(11) _x m, the _{y m,} respectively by an equation, and substituting the expression (5),
Unknowns x _m, does not contain y _m, are the secondary equation for unknowns r _a, r _a is the coordinates of each base station, the solution expressed by the signal arrival time difference from the mobile station M305 measured at each base station It is obtained as The resulting solution _{r a,} (11) By substituting the equation, coordinate values _{x m} and _{y m} of the mobile station M is determined respectively for determining the position of the mobile station M305 is determined.

In FIG. 11, after the positioning signal of each base station, positioning data is transmitted and received by the mobile terminal M305. The base station A data transmission 1105 transmitted from the base station A301 includes the coordinates (x _a , y _a ) of the base station A401. Further, the base station B data transmission 1110 transmitted from the base station B302 includes the coordinates (x _b , y _b ) of the base station B302 and a timer shift T _0b . Similarly, a base station C data transmission (not shown) transmitted from the base station C303 includes the coordinates (x _c , y _c ) of the base station C303 and a timer shift T _0c .

In the two-dimensional positioning by TDOA, it is sufficient if there are at least three base stations. However, radio waves from the base station may not be received by the mobile terminal due to radio wave shielding, etc., so a redundant configuration with four or more base stations should be adopted. Is realistic. FIG. 4 shows the case of four base stations. Deviation _{T 0d} timing in this case the base station D304 is Motomari in the same manner as described above, in the mobile terminal M305, corrected arrival time _{t rd0} from the base station D304 also obtained in a similar manner. Thus, for example if the signal from the base station C303 is interrupted by a signal from a base station D304, using a _{t rd0} instead of _{t rc0} in (9), with _{r d} instead of _{r c,} the base Using the coordinates (x _d , y _d ) of the base station D304 instead of the coordinates (x _c , y _c ) of the station C303, the position coordinates (x _m , y _m ) of the mobile terminal M305 are determined in the same manner as described above. it can.

  In the first embodiment, the number of the mobile terminals 305 is one, but a plurality of mobile terminals may be used. In this case, each base station transmits a positioning signal to each mobile terminal individually for each mobile terminal, or broadcasts the signal radio wave, and each mobile terminal receives the received time from each base station. The position coordinates of the plurality of mobile terminals can be determined using the transmitted time difference data including the clock shift time of each base station and the position coordinates of each base station.

In the second embodiment, a synchronization signal is broadcast from one base station that also serves as a reference station to at least two other base stations, and the time of the received synchronization signal is transmitted to the at least two other base stations. Therefore, each base station measures the deviation of the timer of its own station, and each base station transmits the positioning signal pulse with a transmission time of the positioning signal pulse so as not to overlap in time with the mobile terminal. The difference in the transmission time of the positioning signal is transmitted to the mobile terminal on the data signal from each base station, and the mobile terminal corrects the reception time of the positioning signal transmitted from each base station by the difference in the transmission time. Then, the position of the mobile terminal is detected.
"Communication route configuration of wireless positioning system of Example 2"
The communication route configuration of the wireless positioning system in the present embodiment is the same as that in the first embodiment and is shown in FIG.
"Signal transmission and reception timing at each station in the second embodiment"
FIG. 14 shows signal transmission and reception timing from each station according to the second embodiment.

In FIG. 14, 1401 is a synchronization signal transmission, 1402 is a synchronization reference pulse transmission time t _sa , 1403 is a positioning signal A transmission, 1404 is a reference pulse A transmission time t _ta , 1405 is a base station A data transmission, and 1406 is a synchronization signal reception. , 1407 is a synchronization reference pulse reception time t _sb , 1408 is a positioning signal B transmission, 1409 is a reference pulse B transmission time t _tb , 1410 is a synchronization signal reception, 1411 is a positioning signal A reception, and 1412 is a reference pulse A reception time _tra , 1413 indicates positioning signal B reception, 1414 indicates reference pulse B reception time _trb , and 1415 indicates base station A data reception.

A synchronization signal pulse train 1401 is transmitted from the base station A401, and the position t _sa 1402 of the first pulse after the preamble is used as a time reference. The base station B302, a reference pulse at time t _sb 1407 after _{T p} time is received. The base station A401, a pulse train of positioning signals A1403 is transmitted to the reference pulse transmission after _{T a.}

In the base station B302, after receiving the reference pulse at the time t _sb 1407, after the transmission start time of the positioning signal A1403, it waits for the time of T _wb shown in the equation (12), and after the time when the transmission of the positioning signal A1403 is finished. , from the reference pulse 1407 receiving end after _{T b,} the positioning signal B pulse train 1108 is transmitted.

Where T _as is the transmission period of the positioning signal A 1601 in the base station A, and T _ammax is the maximum propagation delay time in the range in which the mobile terminal _{M 305} moves from the base station A 401.

_Tb is calculated by equation (13).

Positioning signal A pulse 1403 and positioning signal B pulse 1408 have transmission start times shifted by T _wb , and reference pulse time t _ta 1404 after preamble of positioning signal A transmission 1103 of base station A 401 and positioning of base station B 302 The time t _tb 1409 of the reference pulse after the preamble of the signal B transmission 1408 is also shifted by T _wb .

The reference pulse of the positioning signal A pulse train 1403 arrives at the mobile terminal M305 at a time _tra 1412 after T _ma from the transmission time t _ta 1404, and the reference pulse of the positioning signal B pulse train 1408 is transmitted from the transmission time t _tb 1409 to T _mb. It arrives at the mobile terminal M305 at a later time t _rb 1414. In the mobile terminal _M305, by measuring the time of t ra 1412 and _t rb 1414, determine the arrival time difference.

  In Example 2, since the time of the positioning signal transmitted from base station A305 and base station B302 does not overlap, the same PN sequence can be used.

In the second embodiment, the configurations of the base station A 401 and the base station B are the same as those of the first embodiment shown in FIG. 5 and FIG. 6. The correlator 616 of the receiving unit of the base station B 302 in FIG. If the preamble in the reception 1406 is detected and the reference pulse is detected, the value t _sb 1407 of the precise timer at that time is latched and taken into the MPU 601. MPU601 from that point, performs calculation of _{T b} by equation (13), a post _{T b} measured at cycle timer -605, at that time, transmission of the positioning signal pulse train 1408 is started.

In addition, the clock shift T _0b between the base station A 401 and the base station B 302 is calculated by the equation (1) in the MPU 601 as in the first embodiment, and is reflected in T _0b of the equation (13) as correction value transmission data. , (12) is used for setting T _{wb that} satisfies the condition, and the information data of the set T _wb is sent to the mobile terminal M305.

Note that the time position t _sb 1407 of the reference pulse received by the base station B302 is shifted because the first pulse position is hopped by the PN sequence, and thus the hopping value is corrected with respect to the arrival time.

In FIG. 14, after the positioning signal of each base station, data for positioning is transmitted and received by the mobile terminal M305. The base station A data transmission 1405 transmitted from the base station A301 includes the coordinates (x _a , y _a ) of the base station A401. Further, the base station B data transmission transmitted from the base station B302 (not shown) includes the coordinates of the base station B302 _{(x b, y} b) and the difference _{T wb} transmission time. Similarly, the base station C data transmission (not shown) transmitted from the base station C303 includes the coordinates (x _c , y _c ) of the base station C303 and the transmission time difference T _wc .

The difference T _wc between the positioning signal transmission start time at the base station C303 and the positioning signal transmission start time at the base station A 401 is set by the equation (14) for the same purpose as the T _wb .

However, T _bs is the transmission period of the positioning signal B in the base station B, T _bmmax is the maximum propagation delay time in the range in which the mobile terminal M305 moves from the base station B302, and T _wb starts transmission of the positioning signal B1408 in the base station B302. The time difference between the time and the time when the positioning signal A transmission 1403 starts to be transmitted is shown.

Further, the time when the base station C303 satisfies the condition of _{Twc according to} the equation (14) and the transmission of the positioning signal C is calculated by the difference _Tc (15) from the reference pulse reception time.

“Determining Arrival Time Difference and Position Coordinate in Mobile Terminal of Second Embodiment”
The mobile terminal M305 in FIG. 4 obtains the arrival time difference of the positioning signal radio waves from each base station. For example, the base station A401 and the base station B302 do not _output positioning signals at the same time, and are shifted by T _wb. Therefore, the arrival time difference obtained by the mobile terminal M305 is corrected by subtracting T _wb .

  The operation of the mobile terminal M305 will be described with reference to FIG.

  15, 1501 is an MPU (microprocessor unit), 1502 is a latch, 1503 is a latch, 1504 is a PN sequence generator, 1505 is received data, 1506 is a PPM data demodulator, 1507 is a correlator, 1508 is a reference clock, 1509 is a coarse timer, 1510 is a precision timer, 1511 is a pulse detection unit, 1512 is an LNA (low noise amplifier), 1513 is a reception BPF (bandpass filter), and 1514 is a reception antenna.

  Since the signal from each base station is transmitted in a time division manner, the mobile terminal M305 in the second embodiment can receive pulse signals from a plurality of base stations with a single reception function.

  When a pulse signal is received, the edge of the pulse is measured by the coarse timer 1509 and the fine timer 1510 and input to the correlator 1507. Since a common PN sequence is used for each base station, a correlator 1507 performs correlation calculation using one PN sequence generator 1504.

  When the correlator 1507 detects the preamble of the synchronization signal pulse train from the base station A 401, the value of the fine timer and the value of the coarse timer are latched by the first reference pulse after the preamble and input to the MPU 1501. The data transmitted from the base station A 401 is PPM demodulated by the PPM data demodulator 1506 and input to the MPU 1501. The operations of the coarse timer 1509 and the fine timer-1510 are the same as those in the base station B302 of the first embodiment described with reference to FIGS.

In the MPU 15011, the arrival time t _ra 1412 of the positioning signal pulse from the base station A 401 and the arrival time t _rb 1414 of the positioning signal pulse from the base station B 302 are obtained from the values notified from the coarse timer 1509 and the fine timer 1510.

Furthermore, for _trb 1414, since the transmission time of the positioning signal pulse from the base station B302 is shifted by T _wb , the correction is performed by the equation (16).

A value _trb0 corrected by the equation (16) indicates an accurate arrival time.
The base station C304, to the base station A401, using said deviation _{T wc} of _{T wb} and transmission time calculated in the same manner, is corrected arrival time _{t rc0} sought, the equation (17).

  The MPU 1501 in the mobile terminal M305 obtains the arrival time difference from each base station to the mobile terminal M305 using the arrival time of the positioning signal pulse from each base station.

  As the position coordinates of each base station, data transmitted from each base station to the transmission data and notified to the mobile terminal M305 is used.

When the arrival time difference of positioning signal pulses from each base station to the mobile terminal M305 and the position coordinates of each base station are obtained, the position coordinates of the mobile terminal M305 are obtained by (5) to (11) as in the first embodiment. (X _m , y _m ) can be determined.

In the two-dimensional positioning by TDOA, it is sufficient if there are at least three base stations. However, radio waves from the base station may not be received by the mobile terminal due to radio wave shielding, etc., so a redundant configuration with four or more base stations should be adopted. Is realistic. FIG. 4 shows the case of four base stations. Deviation _{T 0d} timing in this case the base station D304 is Motomari in the same manner as described above, in the mobile terminal M305, corrected arrival time _{t rd0} from the base station D304 also obtained in a similar manner. Thus, for example if the signal from the base station C303 is interrupted by a signal from a base station D304, using a _{t rd0} instead of _{t rc0} in (9), with _{r d} instead of _{r c,} the base Using the coordinates (x _d , y _d ) of the base station D304 instead of the coordinates (x _c , y _c ) of the station C303, the position coordinates (x _m , y _m ) of the mobile terminal M305 are determined in the same manner as described above. it can.

  In the second embodiment, the number of mobile terminals 305 is one, but a plurality of mobile terminals may be used. In this case, each base station transmits a positioning signal to each mobile terminal individually for each mobile terminal, or broadcasts the positioning signal pulse, and each mobile terminal receives the positioning signal pulse. The position coordinates of the plurality of mobile terminals can be determined using the time difference data including the clock shift time of each base station transmitted from each base station and the position coordinates of each base station.

In the third embodiment, a positioning signal pulse transmitted from one base station that also serves as a reference station to other base stations and mobile terminals is used as a synchronization signal, and at least two other base stations receive it. Each base station measures the deviation of its own timer from the time of the synchronization signal, and each base station transmits the positioning signal pulse with the transmission time of the positioning signal pulse so that it does not overlap in time with the mobile terminal. To do. The difference in the transmission time of the positioning signal is transmitted to the mobile terminal on the data signal from each base station, and the mobile terminal corrects the reception time of the positioning signal transmitted from each base station by the difference in the transmission time. Then, the position of the mobile terminal is detected.
"Communication route configuration of wireless positioning system of Example 3"
The communication route configuration of the wireless positioning system in the present embodiment is the same as that in the first embodiment and is shown in FIG.
"Signal transmission and reception timing in each station of the third embodiment"
FIG. 16 shows signal transmission and reception timing from each station according to the third embodiment.

In FIG. 16, 1601 is a positioning signal A transmission, 1602 is a reference pulse A transmission time t _ta , 1603 is a base station A data transmission, 1604 is a positioning signal A reception, 1605 is a reference pulse A reception time t _sb , and 1606 is a positioning signal. B transmission, 1607 is a reference pulse B transmission time t _tb , 1608 is a positioning signal A reception, 1609 is a reference pulse A reception time t _sc , 1610 is a positioning signal C transmission, 1611 is a reference pulse B transmission time t _tb , and 1612 is positioning. Signal A reception, 1613 is a reference pulse A reception time _tr , 1614 is a positioning signal B reception, 1615 is a reference pulse B reception time _trb , 1616 is a positioning signal C reception, 1617 is a reference pulse C reception time _trc , and 1618 is Each of base station A data reception is shown.

The positioning signal B transmission 1606 transmitted from the base station B302 is determined in advance by the equation (12) so that it does not overlap with the positioning signal A transmission 1601 of the base station A401 at the mobile terminal M305, as in the second embodiment. The fixed value _Twb is transmitted with a time difference.

Transmission start time of the positioning signal B transmitted 1606 is set from the next clock time _t sb 1605 (18) at the time of waiting time difference _{T b} by formula.

However, T _wb is the time difference according to the equation (12), t _sb is the reference pulse reception time 1605 of the positioning signal A from the base station A 401, T _pb is the propagation delay time from the base station A 401 to the base station B 302, and T _0b is time base station B302 and the base station A401 deviation, _{T k} denotes the clock period, respectively.

Similarly, the transmission start time of the positioning signal C transmission 1611 of the base station C303 is set to a time waiting for a time difference of _{Tc according to} the equation (19) from the clock next to the time _tsc 1609.

Where T _wc is the time difference according to equation (20), T _pc is the propagation delay time from base station A 401 to base station C 303, T _0c is the time lag between base station C 303 and base station A 401, and T _k is the clock period. .

_{However, T bs} indicates the transmission period of the positioning signal B1606 at the base station _{B302, T wb} is the delay time, the positioning signal B1606 base station B302 set in (12), respectively.

  In the third embodiment, since a signal dedicated to synchronization is not required, the configuration of the base station A 401 is simplified.

"Determination method of arrival time difference and position coordinates in mobile terminal of embodiment 3"
The configuration of the mobile terminal M305 is shown in FIG. 15 as in the second embodiment.

  In the third embodiment, in the same manner as the mobile terminal M305 in the second embodiment, the MPU 1501 in the mobile terminal M305 corrects the arrival time of the positioning signal pulse from each base station by using the equations (16) and (17). The arrival time difference from each base station to the mobile terminal M305 is obtained.

  As the position coordinates of each base station, data transmitted from each base station to the transmission data and notified to the mobile terminal M305 is used.

When the arrival time difference of positioning signal pulses from each base station to the mobile terminal M305 and the position coordinates of each base station are obtained, the position coordinates of the mobile terminal M305 are obtained by (5) to (11) as in the first embodiment. (X _m , y _m ) can be determined.

In the two-dimensional positioning by TDOA, it is sufficient if there are at least three base stations. However, radio waves from the base station may not be received by the mobile terminal due to radio wave shielding, etc., so a redundant configuration with four or more base stations should be adopted. Is realistic. FIG. 4 shows the case of four base stations. Deviation _{T 0d} timing in this case the base station D304 is Motomari in the same manner as described above, in the mobile terminal M305, corrected arrival time _{t rd0} from the base station D304 also obtained in a similar manner. Thus, for example if the signal from the base station C303 is interrupted by a signal from a base station D304, using a _{t rd0} instead of _{t rc0} in (9), with _{r d} instead of _{r c,} the base Using the coordinates (x _d , y _d ) of the base station D304 instead of the coordinates (x _c , y _c ) of the station C303, the position coordinates (x _m , y _m ) of the mobile terminal M305 are determined in the same manner as described above. it can.

In the third embodiment, the number of the mobile terminals 305 is one, but a plurality of mobile terminals may be used. In this case, each base station transmits a positioning signal to each mobile terminal individually for each mobile terminal, or broadcasts the signal radio wave, and each mobile terminal receives the received time from each base station. The position coordinates of the plurality of mobile terminals can be determined using the transmitted time difference data including the clock shift time of each base station and the position coordinates of each base station.
(Appendix 1)
A radio positioning system that determines the position coordinates of a mobile terminal by transmitting positioning signal pulses from at least three base stations,
The base station includes one master base station and a plurality of slave base stations,
The main base station is
A means for transmitting a synchronization signal pulse to the slave base station, and a means for transmitting a positioning signal pulse to the mobile terminal at a predetermined time after completion of transmission of the synchronization signal pulse,
The slave base station is
The determination of the reception time of the synchronization signal pulse is performed using a coarse timer that operates with the reference clock and a fine timer that operates with finer increments than the reference clock with reference to the reference clock provided in the slave base station,
Means for measuring a clock shift time between a synchronization signal pulse transmitted from the master base station and a clock of the slave base station;
Means for transmitting a positioning signal pulse to the mobile terminal at a time obtained by adding a time difference including the clock shift time from the synchronization signal pulse reception time of the main base station;
Means for transmitting the time difference data to the mobile terminal,
The mobile terminal
Means for correcting the time at which the positioning signal pulse is received at a predetermined period using data of a predetermined time difference including a clock shift time transmitted from the main base station and the sub base station; Means for determining the position coordinates of the mobile terminal using the time when the signal pulse is received and the position coordinates of the master base station and the slave base station stored in the mobile terminal;
A wireless positioning system comprising:
(Appendix 2)
The base station according to attachment 1, further comprising means for repeating transmission of positioning signal pulses to the mobile terminal at a predetermined cycle.
(Appendix 3)
The base station according to attachment 1, wherein the base station transmits an impulsed ultra-wideband radio signal.
(Appendix 4)
The base station described in Supplementary Note 1 transmits a signal in which a predetermined pseudo-random digital signal is subjected to pulse position modulation with an arbitrary digital signal, and is impulseized at a specific position of the chip width of the pulse position-modulated pseudo-random digital signal. A base station characterized by:
(Appendix 5)
The base station according to appendix 1, wherein a pseudo-random digital signal to be generated uses a signal that is pulse position modulated by a Reed-Solomon code.
(Appendix 6)
The base station as set forth in appendix 1, comprising means for band-limiting an impulse signal to be transmitted with a predetermined band-pass filter.
(Appendix 7)
The slave base station described in appendix 1 determines the determination of the reception time of the synchronization signal pulse between the signal received and detected by the slave base station and the same pseudo-random digital signal as the master base station provided in the slave base station. A base station comprising means for performing time comparison by correlation.
(Appendix 8)
The slave base station according to appendix 1 determines the reception time of the synchronization signal pulse with a coarse timer that operates on the reference clock with reference to a reference clock provided in the slave base station, and in finer increments than the reference clock. A base station characterized by using a precision timer that operates.
(Appendix 9)
The base station described in Supplementary Note 1 transmits a positioning signal pulse to be transmitted to a mobile terminal at a predetermined time with a time difference from which the positioning signal pulses from the main base station and the slave base station do not overlap in time in the mobile terminal. Means to
Means for transmitting time difference data that does not overlap in time to the mobile terminal;
A base station characterized by comprising:
(Appendix 10)
The base station according to attachment 1, further comprising means for repeating the transmission of positioning signal pulses performed at a time difference that does not overlap in time and the transmission of data at the time difference in a predetermined cycle.
(Appendix 11)
The slave base station according to appendix 1, wherein the reception time of the synchronization signal pulse received from the master base station is determined based on a reference clock provided in the slave base station, and a coarse timer that operates with the reference clock; A base station that uses a precision timer that operates in finer increments than the reference clock.
(Appendix 12)
The slave base station described in appendix 1 determines the time for transmitting the positioning signal pulse with a time difference that does not overlap in time, and uses the reference clock provided in the slave base station as a reference to determine whether the slave base station operates with the reference clock. A base station characterized by using a timer and a precision timer that operates in finer steps than the reference clock.
(Appendix 13)
The base station as set forth in appendix 1, comprising means for transmitting a positioning signal pulse having a function of the synchronizing signal pulse.
(Appendix 14)
The base station, comprising: means for repeating transmission of positioning signal pulses having a function of a synchronization signal pulse to the mobile terminal at a predetermined cycle.
(Appendix 15)
The base station described in Supplementary Note 1 includes means for pulse position modulating a predetermined pseudo-random digital signal with an arbitrary digital signal;
Means for generating an ultra-wideband radio signal impulsed at a specific position of the chip width of the pulse position modulated pseudo-random digital signal;
Means for transmitting a positioning signal pulse having the synchronization function by the impulsed ultra-wideband radio signal;
A base station characterized by comprising:
(Appendix 16)
The slave base station according to supplementary note 1 determines the reception time of the positioning signal pulse having the synchronization function received from the master base station with reference to the reference clock provided in the slave base station. A base station characterized in that it is performed using a coarse timer that operates at a fine timer and a fine timer that operates at a finer step than the reference clock.
(Appendix 17)
The mobile terminal according to supplementary note 1 uses a predetermined time difference data including a clock shift time transmitted from the master base station and the slave base station to determine a time at which the positioning signal pulse is received. And means for determining the position coordinates of the mobile terminal using the time when the positioning signal pulse is received and the position coordinates of the master base station and the slave base station stored in the mobile terminal; ,
A mobile terminal comprising:
(Appendix 18)
The mobile terminal described in Appendix 1 is
Means for communicating the position coordinates of the mobile terminal determined by the mobile terminal to a user of the identified other mobile terminal via at least one of the base stations;
Means for communicating to a user of a particular identified fixed terminal via a network connected to the base station;
A mobile terminal comprising:
(Appendix 19)
The mobile terminal described in Supplementary Note 1 includes: a signal received and detected by the mobile terminal to determine the reception time of positioning signal pulses from the primary base station and the slave base station; and the primary base station provided in the mobile terminal A mobile terminal comprising means for performing time comparison based on a correlation between a base station and a pseudo-random digital signal unique to the slave base station.
(Appendix 20)
The mobile terminal according to Supplementary Note 1 uses the time difference data that does not overlap in time to determine the position coordinates of the mobile terminal determined by the mobile terminal to the identified other mobile terminal users. Means to communicate through at least one of the base stations;
Means for communicating to a user of a particular identified fixed terminal via a network connected to the base station;
A mobile terminal comprising:
(Appendix 21)
The mobile terminal according to attachment 1, wherein the mobile terminal received from the base station corrects the time at which the positioning signal pulse is received from the base station using a time difference data that does not overlap in time with a predetermined period A mobile terminal comprising:
(Appendix 22)
The mobile terminal described in Supplementary Note 1 determines the reception time of the positioning signal pulse transmitted from the base station with the time difference, the signal received and detected by the mobile terminal, and each base station provided in the mobile terminal. Means for performing time comparison by correlation with a common pseudo-random digital signal;
A mobile terminal comprising: means for correcting the reception time of the positioning signal pulse with time difference data received from the base station.
(Appendix 23)
The mobile terminal according to appendix 1, the position coordinates of the mobile terminal determined using the reception time of the positioning signal pulse having the function of the synchronization signal pulse, to the user of the specific other mobile terminal identified, Means for communicating via at least one of said base stations;
Means for communicating to a user of a particular identified fixed terminal via a network connected to the base station;
A mobile terminal comprising:
(Appendix 24)
The mobile terminal according to supplementary note 1 includes means for correcting the time at which the positioning signal pulse having the function of the synchronization signal pulse is received at a predetermined period using the time difference data received from the base station. A mobile terminal characterized by that.
(Appendix 25)
The mobile terminal according to attachment 1, wherein the mobile terminal receives and detects the determination of the reception time of the positioning signal pulse having the function of the synchronization signal pulse received from the base station, and the mobile terminal A mobile terminal characterized by performing time comparison based on correlation with a pseudo-random digital signal common to base stations.
(Appendix 26)
A wireless positioning method for determining a position coordinate of a mobile terminal by transmitting positioning signal pulses from at least three base stations,
The base station includes one master base station and a plurality of slave base stations,
The master base station transmitting a synchronization signal pulse to the slave base station;
Transmitting a positioning signal pulse to the mobile terminal at a predetermined time after transmission of the synchronization signal pulse;
The slave base station is
The step of determining the reception time of the synchronization signal pulse using a coarse timer that operates at the reference clock and a fine timer that operates at a finer step than the reference clock with reference to the reference clock provided in the slave base station When,
Measuring a clock shift time between the synchronization signal pulse transmitted from the master base station and the clock of the slave base station;
Transmitting a positioning signal pulse to the mobile terminal at a time obtained by adding a time difference including the clock shift time from the synchronization signal pulse reception time of the main base station;
Transmitting the time difference data to the mobile terminal;
The mobile terminal corrects the reception time of at least three positioning signal pulses at a predetermined period using the time difference data received from the base station;
Determining a difference in propagation delay time of each of the positioning signal pulses from the primary base station and the slave base station to the mobile terminal;
Determining the position coordinates of the mobile terminal using the difference between the propagation delay times of the respective and the position coordinates of the master base station and the slave base station;
Wireless positioning method including.
(Appendix 27)
A program for radio positioning, wherein a synchronization signal pulse is transmitted from one master base station to a plurality of slave base stations, and the slave base station determines a transmission time of a positioning signal pulse to be transmitted to a mobile terminal. ,
A computer provided in the slave base station,
A time Ta from the transmission end time of the synchronization signal pulse at the master base station to _a transmission start time of the positioning signal pulse, and a propagation delay time T of the positioning signal pulse from the master base station to the slave base station means for inputting _pi , a clock shift time T _0i of the slave base station with respect to the clock of the master base station, and a clock cycle T _k in the master base station;
By adding, subtracting, calculating the integer part of division, and multiplying,
T _i = [(T _a −T _pi + T _0i ) divT _k ] × T _k
And means for outputting the calculation result T _i as a time difference from the time when the slave base station receives the synchronization signal pulse of the master base station to the time when the positioning signal pulse is transmitted. ,
Program for wireless positioning to function as.

It is a figure which shows the principle figure of GPS type | mold TDOA. It is a figure which shows the communication route structure of GPS type | mold TDOA. It is a figure which shows the fundamental structure of the communication route by this invention. It is a figure which shows the communication route structure by this invention. It is a figure which shows the base station A block diagram. It is a figure which shows the base station B block diagram. It is a figure which shows a transmission data format. It is a figure which shows the precision timer by a delay circuit with a tap. It is a figure which shows the timing chart of reception time measurement. It is a figure which shows the timing correction of a base station. It is a figure which shows the timing of the signal pulse train of each station. It is a figure which shows the mobile terminal block diagram of Example 1. FIG. It is a figure which shows the positioning calculation method. It is a figure which shows the timing of the signal pulse train of Example 2. FIG. It is a figure which shows the mobile terminal block diagram of Example 2. FIG. It is a figure which shows the timing of the signal pulse train of Example 3.

Explanation of symbols

101 Base station A
102 Base station B
103 Base station C
104 Base station D
105 Mobile terminal M
106 Hyperbola 107 Hyperbola 201 Satellite A
202 Satellite B
203 Satellite C
204 Ground control station 205 Ground mobile terminal M
301 Base station 302 Base station B
303 Base station C
304 Base station D
305 Mobile terminal M
401 Base station A
501 MPU (microprocessor unit)
502 Transmission Data 503 PPM (Pulse Position Modulation) Data Modulation Unit 504 PN Sequence Generation Unit 505 Reference Clock 506 Impulse Generation Unit 507 Transmission BPF (Band Pass Filter)
508 PA (Power Amplifier)
509 Transmitting antenna 601 MPU (microprocessor unit)
602 Transmission data 603 PPM (pulse position modulation) data modulation unit 604 PN sequence generation unit 605 period timer 606 impulse generation unit 607 transmission BPF (band pass filter)
608 PA (Power Amplifier)
609 transmit antenna 610 reference clock 611 receive antenna 612 receive BPF (band pass filter)
613 LNA (Low Noise Amplifier)
614 Pulse detection unit 615 Precision timer 616 Correlator 617 Latch 618 PN sequence generation unit 711 Position hopping for one chip 712 Position hopping for one chip 800 Input signal 811 First delay circuit 812 Second delay circuit 813 Third Delay circuit 814 4th delay circuit 819 9th delay circuit 820 DFF (Delay Flip Flop)
830 Delay 0 output 831 Delay 1 output 832 Delay 2 output 833 Delay 3 output 834 Delay 4 output 839 Delay 9 output 901 Time to latch encoded value with coarse timer 902 Time to latch encoded value with coarse timer 903 Time at which the encoded value is latched by the coarse timer 1000 Synchronization signal pulse P _as
1001 Positioning signal pulse _Par
1002 Synchronous signal pulse P _bs
1003 Positioning signal pulse P _br ,
1101 Synchronization signal transmission 1102 Synchronization reference pulse transmission time t _sa
1103 Positioning signal A transmission 1104 Reference pulse A transmission time t _ta
1105 base station A data transmission 1106 synchronization signal reception 1107 synchronization reference pulse reception time t _sb
1108 Positioning signal B transmission 1109 Reference pulse B transmission time t _tb
1110 Base station B data transmission 1111 Synchronization signal reception 1112 Positioning signal A reception 1113 Positioning signal B reception 1114 Reference pulse A reception time _tra
1115 Reference pulse B reception time _trb
1116 Base station A data reception 1117 Base station B data reception 1201 MPU (microprocessor unit)
1202a Reception block A
1202b Reception block B
1202c Reception block C
1203 Latch 1204 Latch 1205 PN sequence generator 1206 Received data 1207 PPM data demodulator 1208 Correlator 1209 Reference clock 1210 Coarse timer 1211 Precision timer 1212 Pulse detector 1213 LNA (low noise amplifier)
1214 Reception BPF (band pass filter)
1215 reception antenna 1401 synchronization signal transmission 1402 synchronization reference pulse transmission time t _sa
1403 Positioning signal A transmission 1404 Reference pulse A transmission time t _ta
1405 base station A data transmission 1406 synchronization signal reception 1407 synchronization reference pulse reception time t _sb
1408 Positioning signal B transmission 1409 Reference pulse B transmission time t _tb
1410 Sync signal reception 1411 Positioning signal A reception 1412 Reference pulse A reception time _tra
1413 Positioning signal B reception 1414 Reference pulse B reception time _trb
1415 Base station A data reception 1501 MPU (microprocessor unit)
1502 Latch 1503 Latch 1504 PN sequence generator 1505 Received data 1506 PPM data demodulator 1507 Correlator 1508 Reference clock 1509 Coarse timer 1510 Precision timer 1511 Pulse detector 1512 LNA (low noise amplifier)
1513 Received BPF (band pass filter)
1514 Reception antenna 1601 Positioning signal A transmission 1602 Reference pulse A transmission time t _ta
1603 Base station A data transmission 1604 Positioning signal A reception 1605 Reference pulse A reception time t _sb
1606 Positioning signal B transmission 1607 Reference pulse B transmission time t _tb
1608 Positioning signal A reception 1609 Reference pulse A reception time t _sc
1610 Positioning signal C transmission 1611 Reference pulse B transmission time t _tb
1612 Positioning signal A reception 1613 Reference pulse A reception time _tra
1614 Positioning signal B reception 1615 Reference pulse B reception time t _rb
1616 Positioning signal C reception 1617 Reference pulse C reception time _trc
1618 Base station A data reception

Claims (5)

A radio positioning system that determines the position coordinates of a mobile terminal by transmitting positioning signal pulses from at least three base stations,
The base station includes one master base station and a plurality of slave base stations,
The main base station is
Transmitting means for transmitting a synchronization signal pulse to the slave base station ;
A time obtained by adding a predetermined time to the transmission time of the sync pulse, and means for transmitting a first positioning signal pulse to said mobile terminal,
The slave base station is
The determination of the reception time of the synchronizing signal pulses, with reference to the reference clock, wherein the slave base station is provided, a crude timer operates at the reference clock is performed with a precision timer operating in finer increments than the reference clock ,
Means for measuring a time difference T _fb between the reception time of the synchronization signal pulse transmitted from the master base station and the reference clock of the slave base station;
Means for obtaining a clock shift time T _ob between the reference clock of the master base station and the reference clock of the slave base station from the shift time T _fb and a preset delay time T _pb ;
The time obtained by adding the delay times T _ob of the clock to the transmission time of the first positioning signal of the main base station, and means for transmitting the second positioning signal pulse and shift time T _ob of the clock to the mobile terminal Prepared,
The mobile terminal
The time of reception of the second positioning signal pulses, means for correcting by using the shift time T _ob of the clock,
Using the time when the first positioning signal pulse is received and the time when the corrected second positioning signal pulse is received, and the position coordinates of the master base station and the slave base station stored in the mobile terminal, Means for determining a position coordinate of a mobile terminal. The base station comprises means for pulse position modulating a predetermined pseudo-random digital signal with an arbitrary digital signal;
Means for generating an ultra-wideband radio signal impulsed at a specific position of the chip width of the pulse position modulated pseudo-random digital signal;
The radio positioning system according to claim 1, further comprising means for transmitting a synchronization signal pulse and a positioning signal pulse by the impulsed ultra-wideband radio signal. The mobile terminal uses the time offset T _ob of the clock received from the slave base station, you comprising the first, it means for compensation of the time of receiving the second positioning signal pulse The wireless positioning system according to claim 1 . A wireless positioning method for determining a position coordinate of a mobile terminal by transmitting positioning signal pulses from at least three base stations,
The base station includes one master base station and a plurality of slave base stations,
The main base station is
Transmitting a synchronization signal pulse to the slave base station ;
Transmitting a first positioning signal pulse to the mobile terminal at a time obtained by adding a predetermined time to the transmission time of the synchronization signal pulse;
The slave base station is
The determination of the reception time of the synchronizing signal pulses, with reference to the reference clock, wherein the slave base station is provided, carried out using a crude timer operates at the reference clock, the precision timer operating in finer increments than the reference clock Steps,
Measuring a time difference T _fb between the reception time of the synchronization signal pulse transmitted from the master base station and the reference clock of the slave base station;
Said deviation time T _fb, determining a clock drift time T _ob between the reference clock of the reference clock of the main base station from the preset delay time T _pb said slave base station,
Transmitting to the time obtained by adding the delay times T _ob of the clock to the transmission time of the first positioning signal of the main base station, the second positioning signal pulse and shift time T _ob of the clock to the mobile terminal,
The mobile terminal is
Correcting the time at which the second positioning signal pulse is received using the clock shift time _Tob ;
Using the time of reception of the second positioning signal pulses of time and the corrected received the first positioning signal pulse, the position coordinates of the main base station and the subordinate base station stored in the mobile terminal, wherein Determining the position coordinates of the mobile terminal;
Wireless positioning method including. A program for radio positioning, in which a synchronization signal pulse is transmitted from one master base station to a plurality of slave base stations, and the slave base station determines a transmission time of a second positioning signal pulse to be transmitted to a mobile terminal. There,
A computer provided in the slave base station,
The transmission end time of the sync pulse in advance the main base station the main base station notified from the time and T _a to the transmission start time of the first positioning signal pulse,
Propagation delay time T _pi that was known in advance by measuring the positioning signal pulses from the master base station to the slave base station;
A shift time T _0i of the slave base station clock with respect to the master base station clock, which has been known in advance, and
Means for inputting a clock cycle T _k in the main base station previously notified from the main base station;
By adding, subtracting, calculating the integer part of division, and multiplying,
T _i = {(T _a −T _pi + T _0i ) divT _k } × T _k
And means for outputting the calculation result T _i as a time difference from the time at which the slave base station receives the synchronization signal pulse of the master base station to the time at which the positioning signal pulse is transmitted. ,
Program for wireless positioning to function as.

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