JP3318078B2 - Mobile station location device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for transmitting a ranging signal from a plurality of ranging stations whose positions are known to a mobile station whose position is unknown, and measuring the time required for receiving a position signal returned from the mobile station. ,
The present invention relates to a mobile station position specifying device that calculates the distance between each ranging station and the mobile station, and specifies the position of the mobile station based on the distance and the position of each ranging station. In particular, the mobile station multiplexes a ranging signal. The present invention relates to a mobile station position specifying device that returns a common position signal to each ranging station, and each ranging station extracts its own ranging code from the position signal to calculate a distance.

[0002]

2. Description of the Related Art Generally, a mobile object such as a person, an automobile, a ship, and a spacecraft is provided with a mobile station having a transmitting / receiving function, and a ranging signal is transmitted from a plurality of ranging stations whose positions are known to the mobile station. There is known a mobile station position specifying device that specifies the position of a mobile station based on the time required for a position signal returned from the mobile station and the position of each ranging station.

FIG. 4 shows the concept of a mobile station position specifying device using radio waves. In the figure, a mobile station 21 has a transmitter / receiver, and at least three distance measuring stations 22a, 22b and 22c whose positions are known send distance measuring signals to the mobile station 21. The mobile station 21 receives the ranging signal and immediately returns it. The ranging stations 22a, 22b, and 22c calculate the round trip time of the radio wave from the returned signal, and calculate the distances d1, d2, and d3 to the mobile station 21 based on the calculated time. Further, the distances d1, d2, d3 and the distance measuring stations 22a, 22a,
The position of the mobile station 21 is specified from the positions of 22b and 22c.

FIG. 5 shows a mobile station 21 and distance measuring stations 22a and 22.
3b and 22c show the configuration. Ranging stations 22a, 22
b, 22c have the same configuration, and are ranging code generators 23 for respectively generating ranging codes a, b, c specific to each ranging station.
a, 23b, and 23c, transmitters 24a, 24b, and 24c for transmitting the ranging codes a, b, and c on radio waves, and receivers 25a, 25b, and 25c for receiving position signals, and a time difference between transmission and reception. And a distance counter 26a, 26b, 26c for calculating the distance from the mobile station to the mobile station. Further, the ranging station side has a determination unit 27 for specifying the position of the mobile station from the distance between each ranging station and the mobile station.

On the other hand, the mobile station 21 has three sets of receivers and transmitters, and receivers 28a, 28b and 28c and transmitters 29a and 29a.
29b and 29c.

[0006] The ranging stations 22a, 22b and 22c convert the respective ranging codes a, b and c into ranging signals Fa of different frequencies.
, Fb, and Fc, and transmits the result to the mobile station 21.
1 is a receiver 28a, 28 set to each frequency.
The distance measuring signals Fa, Fb and Fc are received by b and 28c, and the position signals Fa ', Fb' and Fc 'having the same frequency as the distance measuring signals Fa, Fb and Fc are returned.

The position signals Fa ', Fb', Fc '
Receivers 25 of distance measuring stations 22a, 22b, 22c respectively
a, 25b, and 25c, and subsequently, the distance counters 26a, 26b, and 26c calculate the distance to the mobile station 21 from the transmission time of the radio wave.

[0008] The determination unit 27 is provided for each of the distance measuring stations 22a and 22.
The position of the mobile station 21 is specified based on the distance between the mobile station 21 and b, 22c.

[0009]

However, in the above-described conventional mobile station position specifying device, the configuration is complicated because the mobile station has a plurality of transmitters for individually transmitting to each ranging station. .

Further, in the configuration of the conventional mobile station position specifying device, when a plurality of mobile stations move in the same area in the same time zone, there is a possibility that the transmitted and received radio waves interfere with each other.
Conventionally, such a case has been dealt with by shifting the communication frequency band of each mobile station.

However, in the method of shifting the communication frequency, it is uneconomical to use the frequency band of the radio wave, and the frequency band to be used must be switched depending on the mobile station to be positioned. Couldn't figure out the location.

Accordingly, an object of the present invention is to solve the above-mentioned problems of the prior art, to have a simple structure, to measure the positions of a plurality of mobile stations moving within the same time zone and in the same area by measuring the distance in the same frequency band. It is an object of the present invention to provide a mobile station position specifying device which can be specified by radio waves for use.

[0013]

[0014]

According to another aspect of the present invention, there is provided a mobile station position specifying apparatus for specifying the positions of a plurality of mobile stations, comprising: a plurality of mobile stations for receiving a ranging signal and returning a position signal; A plurality of ranging stations for transmitting a signal and measuring the distance from the time until the position signal is returned to the mobile station of the transmission source; an ID detection station for identifying the mobile station of the transmission source; In a mobile station position specifying apparatus having a position of a station, ID information of the mobile station, and a determination unit for specifying a position of each mobile station from a distance between each ranging station and the mobile station, each mobile station is a A mobile station ID generator for generating an ID signal unique to each of the distance measuring stations; a plurality of receivers for receiving the distance measuring signals of the respective distance measuring stations; A multiplexing operation unit that generates a signal, a transmitter that returns this position signal, and transmission of another mobile station A probabilistic generator for stochastically determining a transmission timing so as not to interfere with each other, wherein each of the ranging stations generates a ranging code unique to each ranging station; A transmitter that transmits a code as a distance measurement signal by putting the code on a radio wave, a receiver that receives a position signal from the mobile station, and a correlation between the distance measurement code and the position signal unique to the distance measurement station, A distance counter for calculating a time required for transmission / reception and calculating a distance from the transmission source to the mobile station, wherein the ID detection station includes: a receiver for receiving a position signal from the mobile station; A ranging code generator for generating ranging codes for the ranging stations, and a correlation between the ranging code and the position signal of each ranging station,
And a correlator for extracting the ID information by removing the ranging code of each ranging station from the position signal.

[0015]

[0016]

[0017]

[0018]

In the mobile station location specifying apparatus of the present invention, each mobile station is provided with a mobile station ID generator, generates an ID signal of the mobile station, and multiplexes the ID signal with a ranging signal of each ranging station. I do.
The position signal generated by this multiplexing is sent to each ranging station by one transmitter and also sent to the ID detection station.

The ID detecting station has a ranging code generator for generating a ranging code of each ranging station, removes the ranging code of each ranging station from the position signal including the ID signal, and transmits the position signal. The source mobile station can be identified.

The ID information of the specified mobile station is sent to the determination section together with the measured distance between each ranging station and the mobile station, whereby the ID of the mobile station of the transmission source and its position are specified. . According to the mobile station location specifying device of the present invention, each mobile station only needs to have one transmitter, and the structure of the mobile station can be simplified.

Further, the mobile station position specifying device for specifying the positions of the plurality of mobile stations includes a probability generator for determining the timing of transmitting the position signal. The probability generator controls the transmitter to transmit the position signal within a sufficiently short time so that the transmissions of the mobile stations do not interfere with each other.

By the operation of the probability generator, each mobile station can send a position signal to the ranging station and the ID detection station at random so as not to interfere with each other. A mobile station position specifying device for specifying the position of a mobile station can be provided.

[0023]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a configuration of an embodiment of a mobile station position specifying device according to the present invention. The mobile station position identification device 1 of the present embodiment has three ranging stations 2a, 2b, 2c.
And two mobile stations 3x and 3y, an ID detection station 4 for specifying the ID (code for identification) of the mobile station, and a determination unit 5.

The ranging stations 2a, 2b, 2c have the same configuration, and have ranging code generators 6a, 6b, 6c, transmitters 7a, 7b, 7c, and receivers 8a, 8b, 8c, respectively. It has distance counters 9a, 9b, 9c.

The mobile stations 3x and 3y have the same configuration, each having a mobile station ID generator 10x and 10y and three receivers 11x (11xa, 11xb and 11xc) and 11y, respectively.
(11ya, 11yb, 11yc) and multiplexing operation unit 1
2x, 12y, transmitters 13x, 13y, and probability generators 14x, 14y.

The ID detecting station 4 comprises a receiver 15 and three correlators 16a, 16b, 16c connected in series.
And three ranging code generators 17a, 17b, 17c connected to the correlators 16a, 16b, 16c, respectively.
And

The determination unit 5 has a built-in processing circuit (not shown) for calculating the positions of the mobile stations 3x and 3y from the distances between the distance measuring stations 2a, 2b and 2c and the mobile stations 3x and 3y.

Next, the operation of the mobile station location specifying apparatus 1 according to the present embodiment based on the above configuration will be described below. First, at the ranging station 2a, a ranging code a unique to the ranging station 2a is generated by the ranging code generator 6a. This ranging code a is
It has a short period of a predetermined length (2 ^m -1), and a predetermined 0 and 1
Is a signal having the following arrangement. As will be described later, the length and arrangement of the ranging codes a are set such that the correlation with the own ranging code is strong and the correlation with other ranging codes is weak.

The ranging code a of the ranging station 2a is sent to the transmitter 7a, put on a radio wave of a predetermined frequency by the transmitter 7a, and transmitted as a ranging signal F1 to the mobile stations 3x and 3y. Similar to the ranging station 2a, ranging signals F2 and F3 having different frequencies are transmitted from the ranging stations 2b and 2c to the mobile stations 3x and 3y, respectively.

Since the same processing is performed in the mobile station 3x and the mobile station 3y, the following description will focus on the mobile station 3x.

In the mobile station 3x, the ranging signals F1, F2
, F3 are receivers 11x of different frequency bands.
a, 11xb, and 11xc, and sent as an electric signal to the multiplexing calculator 12x. The multiplexing calculator 12x receives the ID generated by the mobile station ID generator 10x.
The signal x is also input.

The ID signal x is a signal of a predetermined length (2 ^x -1) for specifying the mobile station 3x, and the distance measurement signals F1, F
2, F3 and a code arrangement having a weak correlation with ID signals of other mobile stations.

The ID signal x is output by the multiplexing operation unit 12x.
And the ranging signals F1, F2, F3 are subjected to an exclusive OR operation and sent to the transmitter 13x as a multiplexed signal of one system.

On the other hand, the mobile station 3y also has a mobile station ID.
The ID signal y generated by the generator 10y and the ranging signals F1,
F2 and F3 are multiplexed by the multiplexing calculator 12y and sent to the transmitter 13y as one system signal.

The transmitters 13x and 13y include a probability generator 14
Under the control of x and 14y, the multiplexed signal is transmitted as a position signal F0.

The probability generators 14x and 14y operate so that the transmissions of the mobile stations 3x and 3y do not stochastically interfere with each other.
The transmission timing of the transmitters 13x and 13y is determined. In this case, the transmission time of each of the transmitters 13x and 13y should be short enough so that transmission does not interfere with each other, and long enough to be detected and processed later by the ranging stations 2a, 2b and 2c. Have.

FIG. 1 shows a case where the transmitter 13x transmits and the transmitter 1x
3y indicates a state in which transmission is suspended. The position signal F0 of the transmitter 13x is sent to each of the distance measuring stations 2a, 2b, 2c and the ID detecting station 4 as a common position signal. As described above, this position signal F0 includes each ranging station 2a.
, 2b, and 2c, and the ID signal x of the mobile station 3x.

The mobile stations 3x and 3y receive the ranging signal F
The time from receiving 1, F2 and F3 to returning the position signal F0 is short enough not to affect the transmission time of radio waves between the ranging station and the mobile station.

Each of the ranging stations 2a, 2b, 2c receives the position signal F0 and measures the distance to the mobile station 3x. Since the distance measuring process is the same for each of the distance measuring stations 2a, 2b and 2c, only the distance measuring station 2a will be described.

The position signal F0 is received by the receiver 8a and sent to the distance counter 9a as an electric signal that can be processed. In the distance counter 9a, the ranging code a included in the position signal F0 is specified by a correlation method described later, and after transmitting the ranging signal F1 from the phase difference, the position signal F0 is determined.
The transmission time of the radio wave until receiving is calculated. The distance between the ranging station 2a and the mobile station 3x is calculated from the propagation time of the radio wave and sent to the determination unit 5 as distance information.

On the other hand, in the ranging stations 2b and 2c, the ranging station 2b and the mobile station 3x are processed in the same manner as the ranging station 2a.
Are calculated, and the distance between the ranging station 2c and the mobile station 3x is calculated and sent to the determination unit 5.

In the ID detection station 4, the position signal F0 is received by the receiver 15 and sent to the first correlator 16a. The ranging code a of the ranging station 2a generated by the ranging code generator 17a is input to the correlator 16a. In the correlator 16a, the ranging code a in the position signal is specified by a correlation technique, removed from the position signal, and sent to the second correlator 16b. Second and third correlators 16b, 1
In step 6c, the ranging codes b and c are sequentially removed from the position signal by the same processing, and the ID information of the remaining mobile station 3x is sent to the determination unit 5.

The determination unit 5 inputs the distance information and the ID information, and can specify the position of the mobile station 3x from the relationship between the distance measuring stations 2a, 2b, and 2c.

The plurality of mobile stations 3x and 3y alternately transmit position signals by the action of the probability generators 14x and 14y, and the determination unit 5 specifies the ID information and the positions of the mobile stations 3x and 3y in a short time. Therefore, apparently the positions of a plurality of mobile stations can be simultaneously grasped.

FIG. 2 and FIG. 3 explain the processing until the ranging codes a, b, and c are multiplexed by the multiplexing units 12x and 12y and returned as position signals until they are specified by the correlation method. are doing.

As shown in FIG. 2, ranging codes a, b, c
Have a code length of 2 ^m -1, 2 ⁿ -1, and 2 ^r -1 respectively, and have a multiplexing operation unit 1 via distance measurement signals F1, F2 and F3.
2x, 12y, and the multiplexed arithmetic units 12x, 12y
multiplexed with y. The multiplexed signal is, specifically, an exclusive OR of the ranging codes a, b, and c, and has a code length of (2 ^m -1) × (2 ⁿ -1) × (2 ^r -1). )have. The multiplexed signal has a weak correlation with each of the ranging codes a, b, and c or the ID signals x and y in the code length. This multiplexed signal is returned to the ranging stations 2a, 2b, 2c on the position signal F0. In the ranging stations 2a, 2b, 2c, the position signal F0 and the ranging codes a,
b and c are compared to determine a position where the correlation becomes maximum, and the round trip time of the radio wave is calculated from the phase difference.

FIG. 3 is a diagram for explaining the above-mentioned correlation method. As shown in FIG. 3, a device for processing the correlation (distance counters 9a, 9b, 9c or correlators 16a, 16b,
16c), a pair of shift registers (1) and (2) having a ranging code length are provided, and a part of the received signal (position signal F0) is recorded in one shift register (1). And
The ranging codes (a, b, c) are recorded in another shift register (2). The signs of both shift registers are then compared and the number of sign matches / mismatches (correlation) is accumulated. Next, the codes of the distance measurement codes (a, b, c) recorded in the shift register (2) are sequentially shifted by one bit as shown in FIG. The position where all the codes are shifted and the correlation becomes maximum indicates the position of the ranging code included in the received signal, and the round-trip time of the radio wave is calculated from the phase difference of these bits.

As described above, according to the mobile station location specifying apparatus 1 of the present invention, the mobile stations 3x and 3y multiplex the ranging signals and transmit the multiplexed signals by one transmitter 13x and 13y.
Since the a, 2b, and 2c sides determine their own ranging codes from the multiplexed signals and calculate the round trip time of the radio wave, the number of transmitters on the mobile station side is reduced, and the configuration of the apparatus is simplified. be able to. Further, the radio frequency band used for reception and transmission is simplified, and radio waves can be used efficiently.

Further, the ID signal of the mobile station is multiplexed into the position signal, and the ID signal is extracted on the receiving side of the position signal.
By providing the D detection station, the mobile station of the transmission source can be specified together with the position information.

In this way, a plurality of mobile stations can operate in the same time zone.
When moving in the same area, the probability generator that controls the transmission time so that each mobile station does not interfere with each other allows the locations of multiple mobile stations to be grasped almost simultaneously using position signals in the same frequency band. can do.

[0051]

As is apparent from the above description, the mobile station location specifying apparatus of the present invention has a ranging station and a mobile station, and the mobile station is operated by the multiplexing arithmetic unit to determine the ranging signal of each ranging station. Are multiplexed and returned to the ranging station as a common position signal.Each ranging station detects its own ranging signal from the multiplexed position signal and calculates the round trip time of the radio wave. Only one transmitter is required, and a mobile station position identification device with a simple configuration can be obtained.

Further, since the position signals of the mobile station are multiplexed into one, a radio frequency band to be used is small, and radio waves can be used efficiently.

Further, according to the mobile station position specifying apparatus of the present invention for specifying the positions of a plurality of mobile stations, each mobile station has a mobile station ID generator, and this mobile station is identified by the mobile station ID generator. An ID signal to be specified can be generated and this ID signal can be included in the position signal by multiplexing, while the position specifying side has an ID detecting station, and the ID information can be extracted by the ID detecting station. Therefore, the ID and the position of the mobile station can be specified at the same time.

The mobile station position specifying device for specifying the positions of a plurality of mobile stations has a probability generator that determines the transmission timing of the transmitter so that the transmissions of the mobile stations do not interfere with each other. By the operation of the probability generator, each mobile station can transmit position signals one by one in a short time within the same radio frequency band.

As a result, it is possible to obtain a mobile station position specifying device which has a plurality of mobile stations having a simple structure, and which can specify the positions of the plurality of mobile stations almost simultaneously by using a small number of radio frequency bands. it can.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a mobile station position specifying device of the present invention.

FIG. 2 is a diagram showing a flow of multiplexing a plurality of ranging signals and extracting a ranging code from the multiplexed position signals.

FIG. 3 is a diagram specifically illustrating a method of specifying a position of a ranging code from a multiplexed position signal by a correlation method.

FIG. 4 is a diagram conceptually showing the operation of a conventional mobile station position specifying device.

FIG. 5 is a diagram showing a configuration of a conventional mobile station position specifying device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 mobile station position specifying device 2 ranging station 3 mobile station 4 ID detection station 5 determination unit 6 ranging code generator 7 transmitter 8 receiver 9 distance counter 10 mobile station ID generator 11 receiver 12 multiplexing arithmetic unit Reference Signs List 13 transmitter 14 probability generator 15 receiver 16 correlator 17 ranging code generator

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-211469 (JP, A) JP-A-63-235877 (JP, A) JP-A-61-235776 (JP, A) 205579 (JP, A) JP-A-5-264709 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04Q ^7/ 00-7/38 H04B ⁷ /24-7/26

Claims (2)

(57) [Claims] A plurality of mobile stations which receive a ranging signal and return a position signal, and a distance measuring signal are transmitted to determine a distance from a time until the position signal is returned to a mobile station of a transmission source. A plurality of ranging stations to be measured, an ID detecting station for identifying a mobile station as a transmission source, and ID information of each ranging station, ID information of the mobile station, and a distance between each ranging station and the mobile station. A mobile station position specifying device having a determination unit for specifying a position, wherein each of the mobile stations generates a mobile station ID generator for generating an ID signal unique to the mobile station, and a ranging signal of each of the ranging stations. A plurality of receivers for receiving, a multiplexing calculator for multiplexing the ranging signal of each ranging station and the ID signal to generate a position signal, a transmitter for returning this position signal, A probability generator for stochastically determining a transmission timing so as not to interfere with transmission; A ranging code generator for generating a ranging code unique to each ranging station, a transmitter for transmitting the ranging code on a radio wave and transmitting it as a ranging signal, and receiving a position signal from the mobile station. A receiver and a distance counter that calculates the time required for transmission / reception by correlating the distance code unique to the distance measuring station and the position signal, and calculates the distance to the mobile station of the transmission source. The ID detection station has a receiver for receiving a position signal from a mobile station, a ranging code generator for generating a ranging code for each ranging station, a ranging code and a location for each ranging station. Correlate with the signal
A mobile station position specifying device, comprising: a correlator for extracting ID information by removing a ranging code of each ranging station from the position signal. 2. The multiplexing arithmetic unit is configured to perform an exclusive OR operation on a ranging signal of each ranging station or each ranging signal and an ID signal to perform multiplexing. The mobile station location specifying device according to claim 1 , wherein