JP2002040121A - Mobile communication system and mobile station position detection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately detect the position of a mobile station through simple processing by simple constitution, regarding a mobile communication system, and to provide a position detecting method which detect the position of the mobile station. SOLUTION: Position detection information including azimuth information, base station information, and transmission time information is spread and modulated by a spreading series, and transmitted by controlling the directivity of variable directivity antennas 4 of base stations 1-1 to 1-4. The mobile station 2 in radio zones 5-1 to 5-4 imposes reverse spread demodulation on received position detection information by a spread series and finds a correlation value; decides that the time which is closest to the transmission time among reception times corresponding to the peak of the correlation value is the reception time of a direct wave; and calculates the distance between a base station and the mobile station from the propagation time of the radio wave based upon the transmission time and the reception time of the direct wave, so that the position of the mobile station is detected, on the basis of the base station information, azimuth information, and distance information.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention includes a mobile station such as a portable telephone and a plurality of base stations arranged in a distributed manner, and a mobile station in a wireless zone of the base station is connected to another base station via the base station. The present invention relates to a mobile communication system for performing communication with a mobile station, a fixed telephone, or the like, and a position detection method for detecting a position of a mobile station with reference to a base station.

[0002]

2. Description of the Related Art FIG.
Is a base station, 152 is a mobile station, 153 is a transmitter, 154 is a variable directional antenna, 155 is an antenna directivity controller,
156 is an electric field strength measurement unit, 157 is a distance recognition unit, 158
Denotes a direction recognition unit, 159 denotes a position recognition unit, 160 denotes a position data storage unit, 161 denotes a display unit, 162 denotes a demodulation unit, and 163 denotes an omnidirectional antenna.

The variable directional antenna 154 of the base station 151
For example, the directivity is sequentially changed in all directions by mechanically rotating the unidirectional antenna or controlling the excitation phase of the array antenna. Therefore, when a radio wave from the mobile station 152 is received,
The current direction of the mobile station 152 can be determined from the direction of the variable directional antenna 154 at which the received electric field intensity is maximized by the electric field intensity measuring unit 156. That is, the direction recognizing unit 158 determines the mobile station 1 from the base station 151 based on the azimuth information indicating the maximum directivity from the antenna directivity control unit 155 and the received electric field intensity information from the electric field intensity measuring unit 156.
52 directions can be determined.

The distance recognizing unit 157 is provided by the electric field strength measuring unit 1.
Since the reception electric field strength by 56 decreases as the propagation distance of the radio wave increases, the distance between the base station 151 and the mobile station 152 is determined by the reception electric field strength. The position data storage unit 160 stores position data based on azimuth information and distance information. Therefore, the position recognition unit 159 stores the position data
With reference to 60, the position of the mobile station 152 can be recognized. The display unit 161 displays the position of the recognized mobile station 152.
Can be displayed. Also, the transmitting unit 153 sends the mobile station 1
The mobile station 15 transmits the recognized position information to the mobile station 15.
2 can recognize the current position by receiving the position information.

FIG. 19 is an explanatory diagram of a conventional example, in which (A) shows an outline of a mobile communication system, wherein BS1 to BS3 are base stations, BS0 is an auxiliary base station, and MS is a mobile station. The mobile station MS spreads and modulates transmission time information with a spreading sequence and transmits the spread time information. This is received by at least two base stations, a correlation value is obtained by a spreading sequence, a peak position of the correlation value is set as a reception time, and a distance between the base station and the mobile station is determined based on the reception time and the transmission time. Is calculated.

For example, as shown in FIG. 19B, the timing of the peak of the correlation value at the base stations BS1 and BS2 is set as the reception time, and the transmission time of the mobile station MS despread and demodulated is used. The propagation time of the radio wave is obtained, and the distance between the base stations BS1 and BS2 and the mobile station MS is obtained from the propagation time. Since the distance between the two base stations BS1 and BS2 is known, the mobile station is determined by triangulation. The position of the MS can be recognized. In order to enable simultaneous reception by two base stations without increasing the transmission power of the mobile station MS, or when the distance between the base stations BS1 to BS3 is large, the auxiliary base station BS0 is connected between the base stations. In the vicinity of the boundary.

[0007]

The distance between the base station and the mobile station is obtained from the above-mentioned received electric field strength, and the direction at which the received electric field strength becomes maximum is defined as the direction of the mobile station with respect to the base station. In the conventional example which recognizes the direction, the direct wave does not always have the maximum received electric field strength due to fading or the like, so that it is difficult to accurately determine the azimuth. Also, since the received electric field strength fluctuates due to fading, etc.,
There is a disadvantage that the error in the distance calculation due to the received electric field strength becomes extremely large, including the change of the fading environment due to the movement of the mobile station.

A spread modulation signal from a mobile station is received by two base stations, a distance between each base station and the mobile station is calculated by a propagation time of a radio wave based on a transmission / reception time, and is calculated based on a triangulation method. In the conventional example for recognizing the position of a mobile station, the transmission power of the mobile station must be increased so that at least two base stations can receive signals, and there is a problem that the power consumption of the mobile station increases. Further, there is a problem that increasing the transmission power increases interference between other stations, degrades communication quality, and reduces the number of users who can communicate at the same time. Further, in a region where one base station covers a wide area, there is a problem that the position of the mobile station cannot be recognized. In order to solve the problem in this case, it is necessary to provide an auxiliary base station for position detection, which has a disadvantage of increasing costs.

An object of the present invention is to solve the above-mentioned problems of the conventional example and to enable accurate detection of the position of a mobile station.

[0010]

A mobile communication system according to the present invention will be described with reference to FIG. 1. A plurality of base stations 1-1 to 1-4 arranged in a distributed manner and the base stations are connected to each other. A mobile communication system including a mobile station 2 performing communication in
The base station includes a transmitting unit that spreads and modulates the position detection information including the transmission time information, the base station information, and the azimuth information with a spreading sequence, and a variable directional antenna 4 that transmits a radio wave in an azimuth corresponding to the azimuth information. And Also, mobile station 2
A reception unit that receives the modulated position detection information and receives a peak of a correlation value with the spread sequence, a reception unit that outputs demodulated data obtained by despreading and demodulating the position detection information with the spread sequence, and included in the demodulated data. A direct wave determination unit that determines the reception time closest to the transmission time to be the reception time of the direct wave,
The distance between the base station and the mobile station is calculated based on the propagation time of the radio wave between the reception time of the direct wave and the transmission time, and the information of the distance, the base station information, and the direction information are calculated. And a position recognizing unit for obtaining the position of the own mobile station. Also, the base station transmits position detection information in which the transmission time information, the base station information, and the azimuth information correspond to the M-ary orthogonal sequence, and the mobile station determines the position detection information based on the correlation value with the orthogonal sequence. The transmission time information, the base station information, and the direction information may be configured to be identified.

Further, the method for detecting the position of a mobile station according to the present invention is a mobile station including a plurality of base stations 1-1 to 1-4 arranged in a distributed manner and a mobile station 2 communicating with these base stations. A method for detecting a position of a mobile station 2 in a communication system,
Variable directivity in which position detection information including transmission time information, base station information, and azimuth information is spread-modulated by a spreading sequence from base stations 1-1 to 1-4, and the directivity is controlled to an azimuth corresponding to the azimuth information. The mobile station 2 sequentially transmits in all directions from the directional antenna 4, and the mobile station 2 transmits the time included in the timing of the peak of the correlation value between the received position detection information and the spread sequence and the position detection information despread and demodulated by the spread sequence. The time closest to the transmission time is determined as the reception time by the direct wave, and the base station and the mobile station are determined based on the propagation time of the radio wave between the reception time of the direct wave and the transmission time. , And detecting the position of the own mobile station based on the calculated distance information, base station information and azimuth information. The transmission time, the base station information, and the direction information are M-ary.
The mobile station performs despread demodulation with the spread sequence, and performs transmission time and base station transmission based on the correlation value with the orthogonal sequence. A step of demodulating the information and the azimuth information may be included. The accuracy of position detection of the mobile station requires that the time of the clock section of the mobile station match the time of the base station, and a time correction request for that purpose is sent from the mobile station to the base station. The time of the mobile station can be corrected based on response information to which time information is added from the station.

[0012]

FIG. 1 is an explanatory diagram of a system according to an embodiment of the present invention, and shows a CDMA (Code Division Multi).
ple Access) shows an outline of the mobile communication system,
1-1 to 1-4 are base stations, 2 is a mobile station, 3 is an omnidirectional antenna, 4 is a variable directional antenna, and 5-1 to 5-4 are wireless zones. As the variable directional antenna 4, for example, a configuration that mechanically rotates a unidirectional antenna, a configuration that controls the excitation phase of an array antenna, or the like can be applied.

Each of the base stations 1-1 to 1-4 includes azimuth information indicating the radio wave radiation direction of the variable directional antenna 4, base station information such as a base station identification number, and transmission time information. The modulation position detection information subjected to spread modulation is transmitted. The variable directivity antenna 4 sequentially switches its directivity in all directions, and indicates the direction of the directivity by direction information. This azimuth information is, for example, a number indicating a 360 ° angle clockwise around each base station or a wireless zone 5.
When -1 to 5-4 are divided into a plurality of sectors, the sector numbers can be used.

The mobile station 2 receives the modulated position detection information, obtains a correlation value with the spread sequence, and performs despread demodulation. The peak times of a plurality of correlation values corresponding to the delay profile corresponding to the multipath at that time are obtained. Then, based on the transmission time information in the despread demodulated data, the closest peak time of the correlation value from the transmission time is determined to be the reception time of the direct wave, and the time from the transmission time to the reception time is determined by the base station. Is the propagation time of radio waves from Since the propagation speed of the radio wave is known, the distance is calculated from the propagation time of the radio wave between the base station and the mobile station 2. Also, based on the base station information in the despread demodulated data, the current wireless zone 5-1 to 5-4
Can be recognized, and the direction from the base station can be recognized based on the azimuth information. By previously searching a memory storing position information such as latitude and longitude based on azimuth information and distance information centered on the base station using the base station information, azimuth information and distance information, the position of the mobile station is obtained. Can be detected. Also, it reports the detected position information of the mobile station 2 to the serving base station.

FIG. 2 is an explanatory diagram of a base station according to an embodiment of the present invention, in which 11 is a transmission information processing unit, 12 is an antenna directivity control unit, 13 is a non-directional antenna, 14 is a variable directional antenna, 15 is a receiving unit, 16 is a clock unit, 17 is a mapping unit, 18 is a spreading sequence generator, 19 is a carrier generator,
20 and 21 are multipliers, 22 is an antenna switching unit, and 23 is a duplexer.

The transmission information processing unit 11, the mapping unit 17, the spread sequence generator 18, the carrier wave generator 19 and the like constitute a means for transmitting position detection information. The transmission time information according to the time information, the direction information indicating the radiation direction of the radio wave, and the position detection information including the base station information such as the base station identification number are added to the antenna directivity control unit 12 and the mapping unit 17.

The antenna directivity control unit 12 controls the direction of radio wave radiation by the variable directivity antenna 14 according to the azimuth information. When the rotation direction of the unidirectional antenna is controlled, the directivity is in the direction according to the azimuth information. In the case of the array antenna, the directivity is in the direction according to the azimuth information by the excitation phase. Further, the mapping unit 17 converts “1” of data constituting the position detection information into +1 (or −1) and “0” into −.
1 (or +1). The one bit width is defined as Td.

The antenna switching unit 22 is for switching between the omnidirectional antenna 13 and the variable directional antenna 14 for transmission, and the above-described position detection information is modulated into a transmission frequency to be transmitted to the variable directional antenna 14. The communication information from the normal base station to the mobile station is modulated to a transmission frequency corresponding to the channel or the like and transmitted from the omni-directional antenna 13. The received signal from the mobile station received by the omnidirectional antenna 13 is received by the receiving unit 1 via the duplexer 23.
Enter 5 The receiving unit 15 has the same configuration as a normal CDMA receiving unit.

The spreading sequence generator 18 generates a spreading sequence having a period T (≫Td) having a chip width Tc and adds the spreading sequence to a multiplier 20.
The position detection information mapped by the mapping unit 17 is spread-modulated. The carrier generator 19 generates a carrier wave (cosωt) of the transmission frequency and adds the carrier wave to the multiplier 21. The carrier wave generator 19 transmits the modulated position detection information from the variable directional antenna 14 via the antenna switching unit 22 in accordance with the direction information. Send to

FIG. 3 is an explanatory diagram of a spread sequence generator and a transmission format. FIG. 3A shows the spread sequence generator 18 of FIG.
Where 31 is an orthogonal sequence generator, 32 is a multiplier,
Reference numeral 33 denotes a PN (pseudo-random) signal generator. The orthogonal sequence code from the orthogonal sequence generator 31 and the PN signal generator 3
A configuration is shown in which a spread sequence is output by inputting and multiplying the PN code from No. 3 to the multiplier 32, and this spread sequence is input to the multiplier 20 shown in FIG. (B) is PN
An example of a code is shown. When the PN code and the orthogonal sequence code are multiplied by the multiplier 32, a spread sequence shown in (C) is obtained. In this case, for one chip width Tc of the orthogonal sequence code, the PN code indicates an output signal of the multiplier 32 when n = 2 of one chip width nTc.

FIG. 3D shows a transmission format, in which position detection information including azimuth information, base station information and transmission time information is transmitted in the direction of azimuth (1) at time t1, and then moved. A case is shown in which transmission is performed in the direction of azimuth (2) at time t2 after a time Tm for receiving processing at the station. That is, at predetermined time intervals, the position detection information is transmitted at times t1, t2,
.. Are sequentially transmitted in the directions (1), (2),.
The azimuth information can be, for example, the direction of north, south, east, west, and the center around the base station, 360 ° angle information, a sector number, and the like. The base station information can be, for example, a base station identification number to be added to the broadcast information. In this case, since the mobile station recognizes the serving base station information by the broadcast information, the mobile station recognizes the serving base station information by comparing the base station information with the base station information included in the position detection information. It can be confirmed that the information is the position detection information from. Also, the order of the azimuth information, the base station information, and the transmission time information included in the position detection information may be other than the illustrated order.

FIG. 4 is an explanatory diagram of a mobile station according to an embodiment of the present invention, wherein 41 is an antenna, 42 is a duplexer, 43
Is a reception unit, 44 is a transmission unit, 45 is a direct wave determination unit, 46 is a position recognition unit, 47 is a position data storage unit, 48 is a display unit,
Reference numeral 49 denotes a clock correction unit. A radio wave from a base station is received by an antenna 41 and received by a receiving unit 4 via a duplexer 42.
Enter 3 The receiving unit 43 includes a clock unit, demodulates the received signal, inputs the demodulated data to the direct wave determination unit 45, and directly sets the time of each of a plurality of peaks of the correlation value with the spread sequence as the reception time. Wave determination unit 45
To enter.

The direct wave determination unit 45 compares the reception time at the peak of the correlation value with the transmission time included in the demodulated data, and determines the demodulated data at the reception time closest to the transmission time based on the received signal of the direct wave. The signal is determined to be demodulated data, and the propagation time obtained from the demodulated data, the transmission time, and the reception time is added to the position recognition unit 46 as direct wave data. The position data storage unit 47 stores position information such as latitude and longitude corresponding to base station information, azimuth information, and distance information, and the position recognition unit 46 stores the base station information obtained by the direct wave determination unit 45. Since the propagation speed of the radio wave is known based on the propagation time of the radio wave between the base station and the mobile station, the distance between the base station and the mobile station is calculated, and the distance information and the direct wave data are included. Based on the base station information and the azimuth information, position information such as latitude and longitude is obtained from the position data storage unit 47, and the position information is added to the display unit 48 to display the position of the mobile station.

Further, the position information is added to the transmitting section 44, and the transmitting section 44 transmits the position information to the base station via the duplexer 42 and the antenna 41. For position detection, it is necessary that the time of the base station and the time of the mobile station match each other. Therefore, the clock correction unit 49 sends a time correction request to the base station every predetermined period. Is transmitted from the transmission unit 44. In response, the base station returns response information to which time information has been added. The mobile station receiving this response information demodulates in the receiving unit 43 as described above, and the clock correction unit 49 transmits the time information of the base station included in the demodulated data, the transmission time of the correction request, and the response information. Based on the reception time and the known response processing time at the base station, a time information correction signal is generated, and the time information correction signal is added to the clock section of the receiving unit 43 to correct the time.

FIG. 5 is an explanatory diagram of the receiving section, and shows a main part of the configuration of the receiving section 43 of FIG.
Is a sine wave generator that generates a sine wave cos ωt signal having the same frequency as the transmission frequency, 53 is a matched filter for measuring propagation time, 54 is a timing generator, and 55-1 to 5-5
5-3 is a correlator for data demodulation, 56 is a rake combining unit,
57 is a demodulator and 58 is a clock unit.

The position detection information modulated by the transmission frequency is received, and the sine wave generator 52
Are multiplied by the sine wave from the demodulated signal and demodulated, and as the spread-modulated position detection information, the matched filter 53 and the correlator 55-
1 to 55-3. The matched filter 53 is for obtaining a delay profile, like the path search circuit, and has, for example, the configuration shown in FIG.
In the figure, 61 is a shift register, 62 is a register, 63 is a multiplier, and 64 is an adder.

The spread modulation position detection information is input to the shift register 61 and is sequentially shifted.
Are input to a multiplier 63, and a register 62
Are multiplied by the set spreading code, and the respective multiplied output signals are added in the adder 64. The output signal of the adder 64 indicates the correlation value between the spread modulation position detection information and the spread code, and is, for example, as shown in FIG. That is, the peaks of the plurality of correlation values are (a), (b), (c), (d)
Appear on the time series as shown as.

The timing of the peak of the correlation value equal to or higher than a predetermined level such as the noise level is defined as the reception time, and the reception time closest to the transmission time is defined as the reception time of the direct wave. That is, since the direct wave arrives at the shortest distance compared to the delayed wave, the reception time closest to the transmission time of the base station is determined as the reception time of the direct wave even if the correlation value level is lower than the delay wave. I do. The time between the reception time of the direct wave and the transmission time included in the position detection information is defined as the propagation time of the direct wave between the base station and the mobile station. Since the propagation speed of the radio wave is known, the distance can be calculated by multiplying the propagation time by the propagation speed.

The timing generator 54 of the receiver 43
The timing signal corresponding to the peak timing of the correlation value from the matched filter 53 is output to the correlators 55-1 to 55-.
Enter 3 For example, the despread demodulation of the correlator 55-1 is performed at the timing of the maximum correlation value level (b) in FIG. 7, and the inverse of the correlator 55-2 is performed at the timing of the next correlation value level (a). The spread demodulation is performed, and the despread demodulation of the correlator 55-3 is performed at the timing of the next correlation value level (c).

FIG. 8 shows a correlator 55- for data demodulation in FIG.
1 to 55-3, each of which is a correlator 55 having the same configuration, 81 is a multiplier, 82 is a phase controller, 8
3 is an integrator, 84 is a spreading sequence generator. The timing signal from the timing generation unit 54 is input to the phase control unit 82, and the same spread sequence as the spread sequence from the spread sequence generator 18 on the transmission side is generated from the spread sequence generator 84, and the phase of the spread sequence is changed. The signal is controlled by the phase control unit 82 and input to the multiplier 81. That is, the multiplication process is performed while sliding the phase of the spread sequence by the width Tc (or a finer unit) every T ₀ seconds (or a finer unit) with the timing at which the peak of the correlation value is obtained as the phase reference. Then, the integrator 83 integrates for Td, and outputs an integrated value for each Td period as a correlation value, that is, a despread demodulated signal.

Although not shown, the output signal of the integrator 83 and a buffer memory for storing a multiplication result of the input signal and the spread sequence obtained every T ₀ seconds (or a finer unit) are raked. A variable delay circuit for inputting to the synthesizing unit 56 with the phases matched is provided. According to the timing signal, for example, an output signal obtained by despreading and demodulating the delayed wave most delayed with respect to the direct wave can be obtained. Until then, the despread demodulated signals of other delayed waves and direct waves are delayed. As a result, it is possible to rake-combine the received signals of the direct wave and the plurality of delayed waves with their phases being matched.

FIG. 9 is an explanatory diagram of a correlation value in a case where noise and transmission line fluctuation are not taken into consideration. The peak of the correlation value by the matched filter 53 for measuring the propagation time is used by the correlator 55 for data demodulation. The peak value of the correlation value is Td
For each period, it is output from the integrator 83 as +1, -1. Correlator 55 (correlator 55-1, 55-2, 5 in FIG. 5)
The output of 5-3) is combined by the rake combining unit 56 and input to the demodulation unit 57, and the demodulation unit 57 outputs demodulated data of the element ("1", "0"). That is,
If the output of the rake combining unit 56 is larger than the threshold value, it is determined to be “1”;

FIG. 10 shows the direct wave determination section 45 of the mobile station.
91 is a signal recognition unit, 92 is a memory unit,
Reference numeral 93 denotes a direct wave data selection unit. The demodulated data and the reception time from the receiving unit 43 (see FIG. 4) are input to the signal recognizing unit 91, and the base station information, the azimuth information, and the propagation time information are input to the memory unit 92 and temporarily stored therein. The direct wave data selected by the direct wave data selection unit 93 is recognized by the position recognition unit 46.
(See FIG. 4).

The signal recognizing section 91 has, for example, the configuration shown in FIG. 11, wherein 94 is a decoding section, and 95 is a propagation time recognizing section. The decoding unit 94 decodes the direction information, the base station information, and the transmission time information of the message or the position detection information based on the demodulated data. That is, the message, the direction information, the base station information, and the transmission time information are separated from the demodulated data which is the digital signal of the element ("1", "0"). Further, the propagation time recognition unit 95 calculates the propagation time between the base station and the mobile station from the reception time and the transmission time.

As described above, the direct wave data from the direct wave determination unit 45 is input to the position recognition unit 46 (see FIG. 4), and the base station information, the azimuth information, and the propagation time stored in the position data storage unit 47 are stored. By searching for position information corresponding to the information, position information based on, for example, latitude and longitude is obtained, and the position information can be input to the display unit 48 and displayed. In addition, position information can be transmitted to the base station.

FIG. 12 is an explanatory diagram of the M-ary system.
Reference numeral 101 denotes an M-ary transmitting unit, 102 denotes a receiving unit, 103 denotes an M-ary correlator, and 104 denotes a maximum likelihood estimating unit. M-a
The ry transmission unit 101 and the reception unit 102 are connected via a wired or wireless transmission path, and the M-ary transmission unit 101
For m types of data, M orthogonal sequences 1 to M
By assigning (M = 2 ^m ), one of orthogonal sequences 1 to M corresponding to m bits of data to be transmitted is selected and transmitted to the transmission path. Receiving section 102 outputs correlators 1 to M corresponding to orthogonal sequences 1 to M in M-ary correlator 103.
M, and each correlation value output is input to the maximum likelihood estimating unit 104. For example, in the case of m-bit data corresponding to the orthogonal sequence 2, the maximum likelihood estimating unit 104 can decode and output m-bit data because the correlation value of the correlator 2 becomes maximum.

FIG. 13 is an explanatory diagram of a base station according to another embodiment of the present invention, showing a case where the M-ary system shown in FIG. 12 is applied, 111 is a transmission information processing unit, and 112 is an antenna directivity. Control unit, 113 is an omnidirectional antenna, 114
Is a variable directional antenna, 115 is a receiving unit, 116 is a clock unit, 117 is an M-ary transmitting unit, 118 is a PN sequence generator, 119 is a carrier generator, 120 and 121 are multipliers,
122 denotes an antenna switching unit, and 123 denotes a duplexer.

The configuration of the base station is different from that of the mapping section 17 of the configuration of the base station shown in FIG.
Is provided, and a PN sequence generator 118 is provided in place of the spread sequence generator of FIG. 2. Other configurations and operations are the same as those of FIG. 2, and redundant description will be omitted. M-
The primary transmitting section 117 is a M-ary transmitting section 10 shown in FIG.
1 and selects and multiplies an orthogonal sequence corresponding to m bits of data having a chip width Tc and a period Td according to transmission time information, azimuth information, and base station information from the transmission information processing unit 111. Input to the container 120.

The chip width nT from the PN sequence generator 118
The PN sequence of d or Tc and the period T is input to the multiplier 120 for spread modulation, the spread modulation position detection information is input to the multiplier 121, and the sine wave cosωt of the transmission frequency is input from the carrier generator 119 to the multiplier 121. , And multiplies and modulates the modulated position detection information.
Via the variable directional antenna 114 whose directivity is controlled to the azimuth according to the azimuth information.

FIG. 14 is an explanatory view of a receiving section of a mobile station according to another embodiment of the present invention, wherein 131 is a multiplier, 132 is a sine wave generator, 133 is a matched filter for measuring a propagation time, and 134 is Timing generator, 135-1 to 135-
3 is an M-ary correlator, 136 is a rake combining unit, 137
Denotes a demodulator and 138 denotes a clock unit. The mobile station can have substantially the same configuration as that of the mobile station shown in FIG. 4, but the configuration of the receiving unit 43 is changed to the configuration shown in FIG. 14 by applying the M-ary system. It is.

That is, M-ary correlators 135-1 to 135-3 corresponding to the data demodulator correlators 55-1 to 55-3 of the receiving section shown in FIG. 5 are provided. This M-
The ary correlators 135-1 to 135-3 respectively correspond to FIG.
The M-ary correlator 103 has two configurations, outputs M-ary correlation values according to the timing signals of the direct wave and the delayed wave from the timing generation unit 134, and adjusts the phases thereof to the rake combining unit 136. Rake combining is performed by the demodulation unit 137 to obtain demodulated data including azimuth information, base station information, and transmission time information corresponding to the maximum correlation value with the orthogonal sequence. The timing generation unit 134 outputs the reception time of the clock unit 138.

Since the M-ary system associates m-bit data with an orthogonal sequence, when the position detection information including azimuth information, base station information, and transmission time information is compressed and encoded, Correspondingly, there is an advantage that the transmission processing time can be reduced. Therefore, it is easy to increase the resolution in all directions, and there is an advantage that it is easy to increase the direction detection accuracy.

FIGS. 15 and 16 show a flowchart of the position detecting process according to the embodiment of the present invention, in which the processes of the base station and the mobile station are mixed. (1), and the base station transmits position detection information to the azimuth n using the variable directional antenna (2). Upon receiving the position detection information, the mobile station demodulates the data using a correlator (correlator 55-1 to 55-2 in FIG. 5 or M-ary correlator 135-1 to 135-3 in FIG. 14). (4) Recognize the information of the transmission time, the base station, and the direction (5).

Further, a correlation value is obtained by a matched filter (the matched filter 53 in FIG. 5 or the matched filter 133 in FIG. 14) (6), and the correlation value is determined at the timing of the peak of the correlation value equal to or higher than a predetermined level such as the noise level. The corresponding reception time is recognized (7). Then, the propagation time between the base station and the mobile station is calculated using the transmission time and the reception time (8). The propagation time, the base station and the direction are recognized (9) and stored in the memory (10).

Then, it is determined whether or not the position detection information has been transmitted in all directions (11).
For the direction n, set n + 1 (12), step (2)
Then, the position detection information is sent to the azimuth (n + 1). In this case, n is set to a value corresponding to the azimuth resolution. For example, when the sector number is used in a 6-sector configuration, the sector number 1 is set to the initial value n, and n =
When it becomes 6, it can be determined that the transmission of the position detection information in all directions has been completed. Alternatively, the azimuth resolution is 36
If it is 10 ° of 0 °, the azimuth n = 0 ° is set as an initial value and n
= 350 °, it can be determined that transmission in all directions has been completed.

Further, the mobile station extracts data (base station information, azimuth information, propagation time information) having a short propagation time from the storage contents of the memory (13) and, based on the propagation time, extracts data between the base station and the mobile station. The distance is calculated (14). The propagation time between the peak timing time of the correlation value including the multipath of the signal transmitted in each direction and the transmission time is obtained and recorded, and in step (13), the propagation time is calculated. The shortest one is determined as the received data by the direct wave. Thereby, the distance between the base station and the mobile station is calculated.

Then, it recognizes the azimuth and the distance from the base station (15), searches the position data storage unit 47 (see FIG. 4) (16), and obtains position information based on latitude, longitude and the like (1).
7). This position information is displayed in addition to the display unit 48 (see FIG. 4) (18), and the position information is transmitted to the base station (1).
9).

FIG. 17 is an explanatory diagram of the time correction processing. In the above-described position detection, the transmission time and the reception time are used, so that the time of the base station and the time of the mobile station match. It is necessary. Therefore, in the initial state of the time X of the mobile station and the time Y of the base station, the mobile station sends a time correction request to the base station at the time X. Assuming that the propagation time is a, the base station receives the time correction request at time Y + a. The base station sends response information to which the time Y + a is added. Assuming that the response processing time at that time is b, the mobile station receives the response information at the time of X '= X + 2a + b. In this case, the response processing time b at the base station is known, and the mobile station stores the transmission time X of the time correction request.

The mobile station sets the propagation time a to the base station as
a = (X′−X−b) / 2 = ｛(X + 2a + b) −X−
It is determined by b｝ / 2. And from the base station (Y + a)
Is transmitted, the mobile station obtains (Y + a) +
In response to the difference between b + a = Y + 2a + b and the reception time X ′, the clock correction unit 49 (see FIG. 4) can generate a time information correction signal and correct the time of the clock unit of the reception unit 43. Thereby, the clock unit 16 of the base station (see FIG. 2)
The time of the mobile station can be matched with the time of the clock section in the receiving section 43 (see FIG. 4) of the mobile station, so that the position detection in the mobile station can be performed accurately. Step (1) in FIG.
This time correction is for performing the above-described processing, and can be performed at a predetermined cycle or at the time of zone switching.

(Supplementary Note 1) In a mobile communication system including a plurality of distributed base stations and a mobile station communicating with the base station, the base station includes transmission time information and base station information. Transmitting means for spreading and modulating position detection information including information and azimuth information by a spreading sequence, and a variable directional antenna for transmitting a radio wave in an azimuth corresponding to the azimuth information; Receiving the position detection information, the reception time of the peak of the correlation value with the spread sequence,
A receiving unit that outputs demodulated data obtained by despread demodulating the position detection information using the spreading sequence, and a direct wave determining unit that determines the reception time closest to the transmission time included in the demodulated data as a reception time of a direct wave Calculate the distance between the base station and the mobile station based on the propagation time of the radio wave between the reception time of the direct wave and the transmission time, the information of the distance, the base station information and the A mobile communication system comprising: a position recognition unit that obtains a position of a mobile station based on azimuth information. (Supplementary Note 2) The mobile station is based on a matched filter for measuring propagation time for obtaining a correlation value between the received position detection information and the spread sequence, a plurality of correlators for demodulating data, and a correlation value by the matched filter. A timing generator that controls the timing of the plurality of data demodulation correlators and outputs each timing as a reception time; and a rake that combines and combines the phases of the output correlation values of the plurality of data demodulation correlators. A combining unit, a demodulating unit that demodulates output data of the rake combining unit, and compares transmission time information in the demodulated data from the demodulation unit with the reception time from the timing generation unit, and is closest to the transmission time. A direct wave determination unit that determines the reception time as the reception time of the direct wave, and calculates the distance between the base station and the mobile station based on the propagation time between the transmission time and the reception time of the direct wave, and calculates Distance information and mobile communication system according to Supplementary Note 1, wherein the the said orientation information with the base station information and a position recognition section to obtain the position information based on. (Supplementary Note 3) A position data storage unit that stores position data corresponding to the base station information, the direction information, and the distance information,
The position recognition unit, base station information of the position detection information,
3. The mobile communication system according to claim 2, wherein the mobile communication system has a configuration in which the position data storage unit is searched for the position information based on the direction information and the distance information calculated based on the propagation time of the radio wave.

(Supplementary Note 4) In a mobile communication system including a plurality of distributed base stations and a mobile station communicating with the base station, the base station includes transmission time information and base station information. Transmitting means for spreading and modulating the position detection information in which the information and the azimuth information correspond to the orthogonal sequence of the M-ary system by a spreading sequence, and a variable directivity for transmitting a radio wave in the azimuth corresponding to the azimuth information An antenna, the mobile station receives the modulated position detection information, the reception time of the peak of the correlation value with the spread sequence, and despread demodulates the position detection information with the spread sequence, and The M
A receiving unit that outputs demodulated data including the transmission time information, the base station information, and the azimuth information according to a correlation value with the orthogonal sequence of the ary system, and the reception time closest to the transmission time included in the demodulated data. A direct wave determination unit that determines a reception time of a direct wave, and calculates a distance between the base station and the own mobile station based on a propagation time of a radio wave between the reception time of the direct wave and the transmission time. A mobile communication system comprising: a position recognition unit that obtains a position of the own mobile station based on the distance information, the base station information, and the azimuth information.

(Supplementary note 5) In a method for detecting a position of a mobile station in a mobile communication system including a plurality of base stations distributed and arranged and a mobile station communicating with the base station. From the base station, spread-modulated position detection information including transmission time information, base station information, and azimuth information by a spreading sequence, and sequentially from a variable directional antenna that controls directivity to an azimuth corresponding to the azimuth information. The mobile station transmits in all directions, the time of the peak of the correlation value between the received position detection information and the spread sequence, and the transmission time included in the position detection information despread and demodulated by the spread sequence. And the time closest to the transmission time is determined as the reception time of the direct wave, and the base station and the own mobile station are determined based on the propagation time of the radio wave between the reception time of the direct wave and the transmission time. Calculate the distance between Based the calculated out distance information and the base station information and the orientation information, position detecting method characterized by comprising the step of detecting the position of the mobile station. (Supplementary Note 6) In the method for detecting a position of the mobile station in a mobile communication system including a plurality of base stations dispersedly arranged and a mobile station communicating with the base station, From the station, spread-modulates the position detection information corresponding to the M-ary orthogonal sequence with the transmission time information, the base station information, and the azimuth information by a spreading sequence, and controls the directivity to the azimuth corresponding to the azimuth information. The mobile station sequentially transmits in all directions from the variable directional antenna, and the mobile station reverses the received time of the peak of the correlation value between the received position detection information and the spread sequence and the position detection information by the spread sequence. Spread demodulation, and the demodulated data including the transmission time information, the base station information, and the azimuth information based on the correlation value with the M-ary orthogonal sequence, and the reception closest to the transmission time included in the demodulated data. Time The it is determined that the reception time of the direct wave,
The distance between the base station and the mobile station is calculated based on the propagation time of the radio wave between the reception time of the direct wave and the transmission time, and the distance information, the base station information, and the direction information are calculated. A step of detecting the position of the own mobile station based on the method.

(Supplementary note 7) The position detecting method according to Supplementary note 5 or 6, further comprising a step of displaying the detected position information on a display unit of a mobile station and transmitting the position information to the base station. . (Supplementary note 8) The mobile station has a clock unit for obtaining a peak time of the correlation value, sends a time correction request of the clock unit to the base station, and responds to the base station with time information added thereto. The mobile station, the transmission time of the time correction request, the transmission time of the base station included in the response information,
Based on the reception time of the response information and the response processing time at the base station, determine the propagation time of the round-trip radio wave between the mobile station and the base station, and determine the transmission time of the base station and the 7. The position detecting method according to claim 5, further comprising the step of correcting the time of said clock section of said mobile station based on a propagation time and a response processing time of said base station.

[0054]

As described above, the present invention spreads and modulates position detection information including azimuth information, base station information and transmission time information from base stations 1-1 to 1-4 by a spreading sequence. The mobile station 2 that has transmitted in the azimuth according to the azimuth information and received this determines the peak timing of the correlation value with the spread sequence as the reception time, and determines the reception time closest to the transmission time as the reception time of the direct wave. It calculates the distance between the base station and the mobile station by calculating the propagation time of the radio wave, and detects the position of the mobile station based on the azimuth information, the base station information, and the distance information. Since the distance is not determined based on the intensity, it is possible to accurately calculate the distance between the base station and the mobile station without being affected by fading, and by recognizing the azimuth with respect to the base station, Mobile station position can be detected There is an advantage to be. Further, there is an advantage that the position of the mobile station can be detected by a single base station.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a system according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a base station according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram of a spreading sequence generator and a transmission format.

FIG. 4 is an explanatory diagram of a mobile station according to an embodiment of the present invention.

FIG. 5 is an explanatory diagram of a receiving unit.

FIG. 6 is an explanatory diagram of a matched filter for measuring a propagation time.

FIG. 7 is an explanatory diagram of a correlation value.

FIG. 8 is an explanatory diagram of a correlator for data demodulation.

FIG. 9 is an explanatory diagram of a correlation value.

FIG. 10 is an explanatory diagram of a direct wave determination unit.

FIG. 11 is an explanatory diagram of a signal recognition unit.

FIG. 12 is an explanatory diagram of the M-ary system.

FIG. 13 is an explanatory diagram of a base station according to another embodiment of the present invention.

FIG. 14 is an explanatory diagram of a receiving unit of a mobile station according to another embodiment of the present invention.

FIG. 15 is a flowchart of a position detection process according to the embodiment of the present invention.

FIG. 16 is a flowchart of a position detection process according to the embodiment of the present invention.

FIG. 17 is an explanatory diagram of a time correction process.

FIG. 18 is an explanatory diagram of a conventional example.

FIG. 19 is an explanatory diagram of a conventional example.

[Explanation of symbols]

 1-1 to 1-4 Base station 2 Mobile station 3 Non-directional antenna 4 Variable directional antenna 5-1 to 5-4 Wireless zone

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2F029 AA07 AB05 AC02 AC04 AC09 AC13 5J062 AA08 BB01 BB05 CC12 HH04 5K022 EE01 EE24 EE33 5K047 AA01 BB01 BB05 CC01 DD01 DD02 GG34 HH15 HH17 HH42 BB03 MM06 MM06 MM06 MM06 BB08 CC10 DD20 DD30 EE02 EE10 FF03 FF06 GG01 GG11 HH22 KK02

Claims (5)

[Claims] 1. In a mobile communication system including a plurality of distributed base stations and a mobile station communicating with the base station, the base station includes transmission time information, base station information, A transmitting unit that spreads and modulates the position detection information including the azimuth information by a spreading sequence and transmits the radio wave in an azimuth corresponding to the azimuth information, and includes a variable directional antenna, wherein the mobile station is modulated. A reception unit that receives the position detection information and receives a peak value of a correlation value with the spread sequence, and a receiving unit that outputs demodulated data obtained by despread demodulating the position detection information with the spread sequence, and is included in the demodulated data. A direct wave determination unit that determines the reception time closest to the transmission time as the reception time of the direct wave; and the base station and the base station based on the propagation time of the radio wave between the reception time of the direct wave and the transmission time. Distance to mobile station Mobile communication system calculated, characterized in that a position recognizing section for obtaining the position of the mobile station based on the distance information and the base station information and the orientation information. 2. In a mobile communication system including a plurality of distributed base stations and a mobile station communicating with the base station, the base station includes transmission time information, base station information, Transmitting means for transmitting the azimuth information and the position detection information corresponding to the orthogonal sequence of the M-ary system by spreading modulation with a spreading sequence, and a variable directional antenna for transmitting a radio wave in the azimuth corresponding to the azimuth information; The mobile station receives the modulated position detection information, receives the peak of the correlation value with the spread sequence at the reception time, and despreads and demodulates the position detection information with the spread sequence; A receiving unit that outputs demodulated data including the transmission time information, the base station information, and the azimuth information according to a correlation value with the orthogonal sequence of the ary system, and the reception time closest to the transmission time included in the demodulated data. straight A direct wave determination unit that determines the reception time of the wave, and calculates the distance between the base station and the mobile station based on the propagation time of the radio wave between the reception time of the direct wave and the transmission time, A mobile communication system comprising: a position recognition unit that obtains a position of a mobile station based on the distance information, the base station information, and the azimuth information. 3. A method for detecting a position of a mobile station in a mobile communication system including a plurality of base stations arranged in a distributed manner and a mobile station communicating with the base station, From the base station, omnidirectionally sequentially from a variable directional antenna in which position detection information including transmission time information, base station information, and azimuth information is spread-modulated by a spreading sequence, and the directivity is controlled to an azimuth corresponding to the azimuth information. The mobile station, the time of the timing of the peak of the correlation value between the received position detection information and the spread sequence, and the transmission time included in the position detection information despread and demodulated by the spread sequence The time closest to the transmission time is determined as the reception time by the direct wave, and the time between the base station and the own mobile station is determined based on the propagation time of the radio wave between the reception time of the direct wave and the transmission time. Is calculated, and the calculation is performed. Distance information and the base station information on the basis of said orientation information, the position detecting method for a mobile station, characterized in that it comprises the step of detecting the position of the mobile station. 4. A method for detecting a position of a mobile station in a mobile communication system including a plurality of base stations distributed and a mobile station communicating with the base station, From the base station, the transmission time information, the base station information, and the azimuth information are spread-modulated by the spreading sequence with the position detection information corresponding to the M-ary orthogonal sequence, and the directivity is changed to the azimuth corresponding to the azimuth information. The mobile station sequentially transmits in all directions from the variable directional antenna, and the mobile station receives the position detection information and the reception time of the peak of the correlation value between the spread sequence and the position detection information by the spread sequence. Despread demodulation and the M-ar
The demodulated data including the transmission time information, the base station information, and the azimuth information according to the correlation value with the orthogonal sequence of the y method, and the reception time closest to the transmission time included in the demodulated data is the reception time of the direct wave. Determining the distance between the base station and the mobile station based on the propagation time of the radio wave between the reception time of the direct wave and the transmission time, and calculates the distance information and the base station information. Detecting a position of the mobile station based on the azimuth information and the azimuth information. 5. The mobile station has a clock unit for obtaining a peak time of the correlation value, sends a time correction request of the clock unit to the base station, and responds to the base station by adding time information. Transmitting information, the mobile station transmits a time correction request transmission time, the transmission time of the base station included in the response information, the reception time of the response information, the response processing time in the base station, Based on the transmission time of the round-trip radio wave between the mobile station and the base station, based on the transmission time of the base station, the propagation time and the response processing time of the base station, the mobile station 6. The method according to claim 4, further comprising the step of correcting the time of said clock section.