CN101969692A - Mobile phone locating method based on multiple shipborne mobile base stations - Google Patents

Abstract

The invention discloses a mobile phone locating method based on multiple shipborne mobile base stations in the technical field of wireless communication, used for solving the problem of accurate location of a marine target mobile phone. The mobile phone locating method comprises the following steps of sending a location request by a position service center to shipbornea location measurement units of multiple ships; transmitting the location request to the shipborne mobile base stations by the shipbornea location measurement units; sending a dialing detection request to the target mobile phone by the shipborne mobile base stations; sending a burst pulse with a specific time length by the target mobile phone; calculating measurement information of the target mobile phone related to a shipborne mobile base station of the ship by the location measurement units according to the burst pulse with the specific time length sent by the target mobile phone; sending the measurement information and specific information of the ship to a shipborne satellite small station of the ship; sending the information to the position service center by the shipborne satellite small station through a satellite link; and union calculating information returned by each ship by the position service center to obtain the position of the target mobile phone. The invention can realize accurate location of a marine mobile phone without reforming the mobile phone and synchronous time of the mobile phone and the base stations.

Description

Mobile phone positioning method based on multiple shipborne mobile base stations

Technical Field

The invention belongs to the technical field of wireless communication, and particularly relates to a mobile phone positioning method based on a plurality of shipborne mobile base stations.

Background

The statistical data of the international labor organization fishery safety and health report shows that about 80 people die of various marine accidents in every 10 ten thousand fishermen worldwide every year. In 2006, 7 months, the International Maritime Organization (IMO) held a special conference of the safety communication group of small fishing boats at the headquarters of london, drafted the safety standards of small fishing boats, "draft", and specified that mobile phones can replace traditional radio equipment for use. In 2006, the Hainan Hospital office accumulatively uses a mobile phone positioning technology for positioning 5 times, and can calculate the approximate position of the lost-contact fishing boat through related information, wherein 3 times of positioning is performed through China Mobile Hainan division, and 2 times of positioning is performed on a mobile phone through China Unicom Hainan division. Various indications show that the probability of accidents in danger at sea is on an increasing trend, and the mobile phone positioning technology has been originally completely open in the maritime search and rescue.

Currently, widely used mobile phone positioning technologies mainly include a CELL-ID + ta (Time advanced) positioning method, a Time of Arrival (TOA) positioning method, an Angle of Arrival (AOA) positioning method, a Time Difference of Arrival (TDOA) positioning method, and a hybrid positioning method combining several positioning technologies.

The CELL-ID + TA positioning method is the simplest to implement, and the accuracy of the positioning method depends on the size of a base station service area where a mobile phone is located. Under urban environment, the general positioning accuracy can reach 1-2km, and the positioning accuracy can be improved to a certain extent by combining with the specific TA value of a GSM system. The application of CELL-ID + TA in distress search and rescue begins to be explored in China. However, the land base station has limited sea surface coverage and low positioning accuracy, and cannot meet the requirements of maritime search and rescue positioning.

The TOA positioning method measures the arrival time of a signal transmitted by a target mobile phone through 3 or more LMUs (Location Measurement units), thereby realizing the positioning estimation of the mobile phone. The positioning method can avoid synchronization errors only by strictly synchronizing the time of the base station participating in positioning with the time of the mobile phone, and the time synchronization between the base stations can be realized, but the clocks between the mobile phone and the base station always have deviations, and the deviations can cause the TOA positioning accuracy to be sharply reduced.

The AOA positioning method measures the radio wave incident angle of the target handset through the antenna array, and the measurement of the radio wave incident angle can be calculated through the phase difference or power spectral density of the target signal received by the antenna array, that is, the method is known as a phase-comparison and amplitude-comparison method. The AOA positioning method can realize the positioning of the target mobile phone only by two base stations, and the AOA positioning method does not need the clock synchronization between the target mobile phone and the base stations. However, the base station antenna used in the GSM system does not have a direction finding function, and in an actual environment, because a certain shielding object always exists on a wireless link, direct wave signals are few, so that an incident angle error is large, and the AOA positioning method is rarely used alone and is generally used together with other positioning methods.

And the TDOA method calculates the position of the target mobile phone by using hyperbolic triangulation according to the TOA information and the time reference value acquired by each LMU. For a synchronous base station, measurements can be made by normal or virtual triggering; if the clocks between the base stations are not exactly synchronized, the mobile communication network also needs to measure the Relative Time Deviation (RTD) or the Absolute Time Deviation (ATD) between the base stations to obtain the actual Time Deviation. The TDOA location method requires at least 3 or more than 3 base stations to locate the mobile phone. In the positioning of the marine handset, limited by the geographical conditions, the marine handset is difficult to be simultaneously in the coverage of 3 or more than 3 terrestrial base stations, and even if the marine handset can receive signals of 3 or more than 3 base stations, because the terrestrial base stations are distributed in one direction, the HDOP (Horizontal resolution of Precision factor) of TDOA positioning is also seriously affected.

Because the mobile phone positioning technology is realized based on the land base station, the technology is difficult to be applied to mobile phone positioning of fishermen in ocean operation. At present, China traffic communication information center and China Integrated network communication Limited company have jointly developed a marine shipborne mobile base station based on communication satellites. The shipborne Mobile base station is connected with a Public Switched Telephone Network (PSTN) and a Public Land Mobile Network (PLMN) through a satellite link, can be installed on a search and rescue ship, a fishery administration ship or a cruise ship, and can provide communication service of a common Mobile phone for ships in ocean operation. By means of the shipborne mobile base station, how to improve the positioning precision of the maritime target mobile phone is achieved, and therefore the method has important significance in improving the maritime distress search and rescue speed and guaranteeing personal and property safety of maritime operation personnel.

Disclosure of Invention

The invention aims to provide a mobile phone positioning method based on a plurality of shipborne mobile base stations, which comprehensively utilizes AOA and TDOA positioning technologies, combines the mobility of the shipborne mobile base stations and the characteristics of wide coverage of communication satellites and the like, does not need strict time synchronization between the base stations and mobile phones, realizes the accurate positioning of the plurality of shipborne mobile base stations on a mobile phone of a marine target, and provides a quick and accurate mobile phone positioning method for maritime salvage departments.

The technical scheme is that the mobile phone positioning method based on a plurality of shipborne mobile base stations obtains the measurement information of a target mobile phone through the shipborne mobile base stations and a shipborne positioning measurement unit, and utilizes a shipborne VAST small station to send the obtained measurement information and the specific information of a ship to which the shipborne mobile base station belongs to an information service center through a satellite link, and the information service center jointly calculates the position of the target mobile phone, and is characterized by comprising the following steps:

step 1: the method comprises the following steps that a position service center sends positioning requests containing target mobile phone numbers to shipborne positioning measurement units of a plurality of ships through a ground satellite master station;

step 2: after receiving the positioning request containing the target mobile phone number, the shipborne positioning measurement unit of each ship forwards the positioning request to the shipborne mobile base station of the ship;

and step 3: sending a dial testing request to a target mobile phone by the shipborne mobile base station of each ship;

and 4, step 4: after receiving the dial testing request, the target mobile phone sends a burst pulse with a specific duration;

and 5: the positioning measurement unit of each ship calculates the measurement information of the target mobile phone relative to the ship-borne mobile base station of the ship according to the burst pulse of the specific time length sent by the target mobile phone;

step 6: the positioning measurement unit of each ship sends the measurement information and the specific information of the ship to the shipborne satellite small station of the ship;

and 7: the shipborne satellite small station of the ship sends the measurement information and the specific information to a position service center through a satellite link;

and 8: and the position service center performs combined calculation on the measurement information and the specific information returned by each ship to obtain the position of the target mobile phone.

The specific information includes longitude and latitude, course, speed, roll and pitch information.

The measurement information is specifically a time of arrival TOA value.

The position service center performs combined solution on the measurement information and the specific information returned by each ship to obtain the position of the target mobile phone, and specifically, the position service center performs combined solution by using the TOA value of the arrival time, the longitude and latitude information and the course information returned by each ship to obtain the position of the target mobile phone.

The position service center performs joint solution on the values returned by the ships to obtain the position of the target mobile phone, and specifically, the position service center calculates a time difference of arrival (TDOA) value according to the TOA value of the arrival time returned by the ships, and then performs joint solution by using the TDOA value, longitude and latitude information and course information to obtain the position of the target mobile phone.

The measurement information is specifically a time of arrival TOA value and an angle of arrival AOA value.

The position service center performs joint solution on the measurement information and the specific information returned by each ship to obtain the estimated position of the target mobile phone, and specifically, the position service center calculates a time difference of arrival (TDOA) value by using a TOA value of arrival time returned by each ship, and performs joint solution by using the TDOA value, an AOA value of an arrival angle, longitude and latitude information and course information to obtain the position of the target mobile phone.

The invention dials and measures and obtains the TOA value of the arrival time and the AOA value of the arrival angle of the target mobile phone through the shipborne positioning measurement unit, and realizes the accurate positioning of the marine mobile phone by using a positioning technology with less base stations. The method does not need to modify the mobile phone equipment, does not need time synchronization between the mobile phone and the base station, and solves the problem of quick positioning of the ocean operation ship in danger.

Drawings

Fig. 1 is a working schematic diagram of a mobile phone positioning method based on a plurality of shipborne mobile base stations;

fig. 2 is a flow chart of a handset positioning method based on a plurality of shipborne mobile base stations;

FIG. 3 is a diagram of a positioning measurement unit setup protocol format;

FIG. 4 is a schematic diagram of the TOA location algorithm;

FIG. 5 is a schematic diagram of a TDOA-AOA location algorithm.

Detailed Description

The preferred embodiments will be described in detail below with reference to the accompanying drawings. It should be emphasized that the following description is merely exemplary in nature and is not intended to limit the scope of the invention or its application.

Fig. 1 is a working schematic diagram of a handset positioning method based on a plurality of shipborne mobile base stations. The shipborne equipment of 2 ships is shown in fig. 1, and in the practical implementation process, the shipborne equipment of 3 or more than 3 ships is preferably used for positioning the target mobile phone. In fig. 1, the land device includes a VSAT master station, a location service center, and a core network device. The VSAT master station is used as a channel for data transmission of the position service center and the core network to complete the interaction of land data and ship data through a VSAT satellite; the position service center is used for initiating a search and rescue task, jointly resolving positioning data and forwarding distress position information. The location service center may be located in a search and rescue command center of a transportation department, and the core Network device completes access from a ship-mounted Mobile base station to a PLMN (Public land Mobile Network) and a PSTN (Public Switched telephone Network). The space segment equipment is a VSAT satellite and completes the forwarding of information of a VSAT main station and VSAT small stations. The shipborne equipment comprises a VSAT small station, a shipborne mobile base station and an LMU (Location Measurement Unit). The VSAT small station is used as a communication channel among the shipborne mobile base station, the positioning measurement unit and the land equipment, and the interaction of ship-side data and land data through a VSAT satellite is completed. The shipborne mobile base station maintains the distribution of links with the maritime mobile phone users, and is matched with the positioning measurement unit to trigger the target mobile phone dial test request; the positioning and measuring unit is used for measuring the TOA and AOA information of the target mobile phone relative to the shipborne mobile base station and returning the TOA and AOA information to the terrestrial position service center through the satellite link.

Example 1

In this embodiment, the TOA value calculated by the onboard positioning measurement unit of each ship is used to calculate the position of the target mobile phone, so this embodiment may also be referred to as a TOA positioning algorithm, and the process is shown in fig. 2. In fig. 2, communication between a VAST satellite main station and a VAST satellite small station via a satellite link is collectively referred to as a VAST communication system.

Step 101: the position service center sends positioning requests containing target mobile phone numbers to shipborne positioning measurement units of a plurality of ships through a ground satellite main station.

The positioning request sent by the position service center through the ground satellite main station is firstly received by each ship-borne satellite small station, and then the ship-borne satellite small station sends the positioning request to the ship-borne positioning measurement unit.

Step 102: after receiving the positioning request containing the target mobile phone number, the shipborne positioning measurement units of all ships forward the positioning request to the shipborne mobile base station of the ship.

Step 103: and the shipborne mobile base stations of all ships send dial testing requests to the target mobile phone.

Step 104: and after receiving the dial testing request, the target mobile phone sends the burst pulse with specific duration.

Step 105: and the positioning measurement unit of each ship calculates the TOA value of the target mobile phone relative to the ship-borne mobile base station of the ship according to the burst pulse of the specific time length sent by the target mobile phone.

Step 106: and the positioning measurement unit of each ship sends the TOA value of the arrival time and the longitude and latitude, the course, the navigational speed, the rolling and pitching information of the ship to the shipborne satellite substation of the ship.

The positioning measurement unit and the shipborne satellite small station carry out data communication through a set protocol. Fig. 3 is a diagram of a protocol format set by the positioning measurement unit, and in fig. 3, the positioning measurement unit sends the TOA value and the longitude and latitude, the course, the navigational speed, the rolling and pitching information of the ship to the shipborne satellite small station of the ship according to the preset protocol format. The AOA data field in fig. 3 may be nulled if the location measurement unit is not required to provide an angle of arrival AOA value.

Step 107: and the ship-borne satellite small station of the ship sends the TOA value of the arrival time, the longitude and latitude, the course, the navigational speed, the rolling and pitching information of the ship to a position service center through a satellite link.

Step 108: and the position service center performs joint calculation by using the TOA value of the arrival time, the longitude and latitude information and the course information returned by each ship to obtain the position of the target mobile phone.

Fig. 4 is a schematic diagram of the TOA positioning algorithm, as shown in fig. 4, when there are 3 measuring vessels equipped with onboard mobile base stations for positioning the target handset,assuming that the coordinates of the target mobile phone are (x, y), the coordinates of the shipborne mobile base station are (x)_i，y_i) i-1, 2, 3, whose coordinates are obtained by latitude and longitude. Target mobile phone to shipborne mobile base station BS_iIs denoted as r_i＝t_ic, where t is_iThe TOA value is the arrival time, and c is the propagation velocity of the radio wave, and the following relations are provided:

${\left({x-x}_i\right)}^2+{\left({y-y}_i\right)}^2={\mathrm{<figure-callout\; id="2"\; label="r\; i"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">r</figure-callout>}}_i^{},i=\mathrm{1,2,3}---\left(1\right)$

in the above formula x_i，y_i，r_iIt is known that theoretically, two unknowns in the formula (1) can be solved by only two equations. Since it is a quadratic binary equation, a third equation is needed to solve the ambiguity, and subtracting the equation (1) from i ═ 1, 2, 3 yields:

${\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">r</figure-callout>}}_2^2-{\mathrm{<figure-callout\; id="1"\; label="r"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">r</figure-callout>}}_1^2=x_2^2+{\mathrm{<figure-callout\; id="2"\; label="y"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">y</figure-callout>}}_2^2-({\mathrm{<figure-callout\; id="1"\; label="x"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">x</figure-callout>}}_1^2+{\mathrm{<figure-callout\; id="1"\; label="y"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">y</figure-callout>}}_1^2)-2(x_2-x_1)x-2(y_2-y_1)y---\left(2\right)$

${\mathrm{<figure-callout\; id="3"\; label="r"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">r</figure-callout>}}_3^2-{\mathrm{<figure-callout\; id="1"\; label="r"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">r</figure-callout>}}_1^2=x_3^2+{\mathrm{<figure-callout\; id="3"\; label="y"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">y</figure-callout>}}_3^2-({\mathrm{<figure-callout\; id="1"\; label="x"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">x</figure-callout>}}_1^2+{\mathrm{<figure-callout\; id="1"\; label="y"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">y</figure-callout>}}_1^2)-2(x_3-x_1)x-2(y_3-y_1)y---\left(3\right)$

rearranging equations (2) and (3) can obtain:

$\left[\begin{array}{cc}{x}_{21}& y_{21}\\ x_{31}& y_{31}\end{array}\right]\left[\begin{array}{c}x\\ y\end{array}\right]=\frac{1}{2}\left[\begin{array}{c}{\mathrm{<figure-callout\; id="2"\; label="K"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">K</figure-callout>}}_2^2-{\mathrm{<figure-callout\; id="1"\; label="K"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">K</figure-callout>}}_1^2-{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">r</figure-callout>}}_2^2+{\mathrm{<figure-callout\; id="1"\; label="r"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">r</figure-callout>}}_1^2\\ {\mathrm{<figure-callout\; id="3"\; label="K"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">K</figure-callout>}}_3^2-{\mathrm{<figure-callout\; id="1"\; label="K"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">K</figure-callout>}}_1^2-{\mathrm{<figure-callout\; id="3"\; label="r"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">r</figure-callout>}}_3^2+{\mathrm{<figure-callout\; id="1"\; label="r"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">r</figure-callout>}}_1^2\end{array}\right]---\left(4\right)$

wherein,

x_i1＝x_i-x₁，y_i1＝y_i-y₁the formula (4) is changed to obtain:

$A\left[\begin{array}{c}x\\ y\end{array}\right]=b---\left(5\right)$

wherein, $A=\left[\begin{array}{cc}{x}_{21}& y_{21}\\ x_{31}& y_{31}\end{array}\right],b=\frac{1}{2}\left[\begin{array}{c}{\mathrm{<figure-callout\; id="2"\; label="K"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">K</figure-callout>}}_2^2-{\mathrm{<figure-callout\; id="1"\; label="K"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">K</figure-callout>}}_1^2-{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">r</figure-callout>}}_2^2+{\mathrm{<figure-callout\; id="1"\; label="r"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">r</figure-callout>}}_1^2\\ {\mathrm{<figure-callout\; id="3"\; label="K"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">K</figure-callout>}}_3^2-{\mathrm{<figure-callout\; id="1"\; label="K"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">K</figure-callout>}}_1^2-{\mathrm{<figure-callout\; id="3"\; label="r"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">r</figure-callout>}}_3^2+{\mathrm{<figure-callout\; id="1"\; label="r"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">r</figure-callout>}}_1^2\end{array}\right].$

if the number N of the base stations participating in positioning is more than 3, solving the formula (5) by using a least square method to obtain:

$\left[\begin{array}{c}x\\ y\end{array}\right]={\left(A^{T}A\right)}^{-1}{A}^{T}b---\left(6\right)$

wherein, $A=\left[\begin{array}{cc}{x}_{21}& y_{21}\\ x_{31}& y_{31}\\ .& .\\ .& .\\ .& .\\ x_{N1}& {\mathrm{<figure-callout\; id="1"\; label="y\; N"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">y</figure-callout>}}_N\end{array}\right],b=\frac{1}{2}\left[\begin{array}{c}{\mathrm{<figure-callout\; id="2"\; label="K"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">K</figure-callout>}}_2^2-{\mathrm{<figure-callout\; id="1"\; label="K"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">K</figure-callout>}}_1^2-{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">r</figure-callout>}}_2^2+{\mathrm{<figure-callout\; id="1"\; label="r"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">r</figure-callout>}}_1^2\\ {\mathrm{<figure-callout\; id="3"\; label="K"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">K</figure-callout>}}_3^2-{\mathrm{<figure-callout\; id="1"\; label="K"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">K</figure-callout>}}_1^2-{\mathrm{<figure-callout\; id="3"\; label="r"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">r</figure-callout>}}_3^2+{\mathrm{<figure-callout\; id="1"\; label="r"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">r</figure-callout>}}_1^2\\ .\\ .\\ .\\ K_N^2-{\mathrm{<figure-callout\; id="1"\; label="K"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">K</figure-callout>}}_1^2-{\mathrm{<figure-callout\; id="2"\; label="r\; N"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">r</figure-callout>}}_N^{}+{\mathrm{<figure-callout\; id="1"\; label="r"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">r</figure-callout>}}_1^2\end{array}\right].$

thus, (x, y) that can be obtained is the position of the target handset.

Example 2

In the embodiment, the time of arrival TOA value calculated by the shipborne positioning measurement unit of each ship is used to calculate the time difference of arrival TDOA value, and then the time difference of arrival TDOA value, longitude and latitude information and heading information are used to perform joint solution to obtain the position of the target mobile phone.

Step 201: the position service center sends positioning requests containing target mobile phone numbers to shipborne positioning measurement units of a plurality of ships through a ground satellite main station.

The positioning request sent by the position service center through the ground satellite main station is firstly received by each ship-borne satellite small station, and then the ship-borne satellite small station sends the positioning request to the ship-borne positioning measurement unit.

Step 202: after receiving the positioning request containing the target mobile phone number, the shipborne positioning measurement units of all ships forward the positioning request to the shipborne mobile base station of the ship.

Step 203: and the shipborne mobile base stations of all ships send dial testing requests to the target mobile phone.

Step 204: and after receiving the dial testing request, the target mobile phone sends the burst pulse with specific duration.

Step 205: and the positioning measurement unit of each ship calculates the TOA value of the target mobile phone relative to the ship-borne mobile base station of the ship according to the burst pulse of the specific time length sent by the target mobile phone.

Step 206: and the positioning measurement unit of each ship sends the TOA value of the arrival time and the longitude and latitude, the course, the navigational speed, the rolling and pitching information of the ship to the shipborne satellite substation of the ship.

The positioning measurement unit and the shipborne satellite small station carry out data communication through a set protocol, and the set protocol format is the same as that in the step 106.

Step 207: and the ship-borne satellite small station of the ship sends the TOA value of the arrival time, the longitude and latitude, the course, the navigational speed, the rolling and pitching information of the ship to a position service center through a satellite link.

Step 208: the position service center calculates the TDOA value according to the TOA value of the arrival time returned by each ship, and then performs joint calculation by using the TDOA value, the longitude and latitude information and the course information to obtain the position of the target mobile phone. The specific process is as follows:

firstly, the TDOA value of the arrival time difference is calculated according to the TOA value of the arrival time returned by each ship. Defining shipborne base stations BS_iAnd BS₁The distance difference between the target mobile phone and the target mobile phone is r_i1Then, the following relationship is present:

r_i1＝r_i-r₁＝(t_i-t₀)c-(t₁-t₀)c＝(t_i-t₁)c (7)

wherein t is_iIndicating the arrival of the target handset at the BS_iTime of arrival TOA value, t₀Indicating the initial time of the measurement. t is t_i-t₁Is that the target handset arrives at the BS_iTOA value of time of arrival and BS of arrival of target mobile phone₁The difference of the TOA value of the time of arrival of the target mobile phone, that is, the target mobile phone arrives at the BS_iAnd BS₁Time difference of arrival TDOA values.

And then, carrying out joint solution by using the TDOA value, the longitude and latitude information and the course information to obtain the position of the target mobile phone. The target mobile phone initial time t can be seen from the formula (7)₀The error caused is eliminated, let i equal to 2, then equation (2) can be written as:

${(r_{21}+r_1)}^2={\mathrm{<figure-callout\; id="2"\; label="K"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">K</figure-callout>}}_2^2-{\mathrm{<figure-callout\; id="1"\; label="K"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">K</figure-callout>}}_1^2-2x_{21}x-2y_{21}y+{\mathrm{<figure-callout\; id="1"\; label="r"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">r</figure-callout>}}_1^2---\left(8\right)$

expanding equation (8) can be written as:

$x_{21}x+y_{21}y=-r_{21}{\mathrm{<figure-callout\; id="1"\; label="r"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">r</figure-callout>}}_1+\frac{1}{2}({\mathrm{<figure-callout\; id="2"\; label="K"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">K</figure-callout>}}_2^2-{\mathrm{<figure-callout\; id="1"\; label="K"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">K</figure-callout>}}_1^2-r_{21}^2)---\left(9\right)$

similarly, equation (3) can be written as:

$x_{31}x+y_{31}y=-r_{31}{\mathrm{<figure-callout\; id="1"\; label="r"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">r</figure-callout>}}_1+\frac{1}{2}({\mathrm{<figure-callout\; id="3"\; label="K"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">K</figure-callout>}}_3^2-{\mathrm{<figure-callout\; id="1"\; label="K"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">K</figure-callout>}}_1^2-r_{31}^2)---\left(10\right)$

writing equations (9) and (10) in matrix form:

$A\left[\begin{array}{c}x\\ y\end{array}\right]=r_{1}c+d---\left(11\right)$

wherein $c=\left[\begin{array}{c}-r_{21}\\ -r_{31}\end{array}\right],d=\frac{1}{2}\left[\begin{array}{c}{\mathrm{<figure-callout\; id="2"\; label="K"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">K</figure-callout>}}_2^2-{\mathrm{<figure-callout\; id="1"\; label="K"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">K</figure-callout>}}_1^2-r_{21}^2\\ {\mathrm{<figure-callout\; id="3"\; label="K"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">K</figure-callout>}}_3^2-{\mathrm{<figure-callout\; id="1"\; label="K"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">K</figure-callout>}}_1^2-r_{31}^2\end{array}\right].$

Let r be₁As is known, equation (11) can be transformed into:

$\left[\begin{array}{c}x\\ y\end{array}\right]=r_1{A}^{-1}c+A^{-1}d---\left(12\right)$

by substituting formula (12) for formula (1) and making i equal to 1, one can obtain a compound of formula r₁The position of the target mobile phone can be obtained by substituting the positive root of the quadratic equation into the equation (12). In some cases r₁Two positive roots may occur and solving for such a ambiguity can be determined from a priori probabilities.

If the number N of the base stations participating in positioning is more than 3, solving the formula (11) by using a least square method to obtain:

$\left[\begin{array}{c}x\\ y\end{array}\right]={\left(A^{T}A\right)}^{-1}{A}^T(r_{1}c+d)---\left(13\right)$

wherein $A=\left[\begin{array}{cc}{x}_{21}& y_{21}\\ x_{31}& y_{31}\\ .& .\\ .& .\\ .& .\\ x_{N1}& {\mathrm{<figure-callout\; id="1"\; label="y\; N"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">y</figure-callout>}}_N\end{array}\right],c=\left[\begin{array}{c}-r_{21}\\ -r_{31}\\ .\\ .\\ .\\ -{\mathrm{<figure-callout\; id="1"\; label="r\; N"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">r</figure-callout>}}_N\end{array}\right],d=\frac{1}{2}\left[\begin{array}{c}{\mathrm{<figure-callout\; id="2"\; label="K"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">K</figure-callout>}}_2^2-{\mathrm{<figure-callout\; id="1"\; label="K"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">K</figure-callout>}}_1^2-r_{21}^2\\ {\mathrm{<figure-callout\; id="3"\; label="K"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">K</figure-callout>}}_3^2-{\mathrm{<figure-callout\; id="1"\; label="K"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">K</figure-callout>}}_1^2-r_{31}^2\\ .\\ .\\ .\\ K_N^2-{\mathrm{<figure-callout\; id="1"\; label="K"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">K</figure-callout>}}_1^2-{\mathrm{<figure-callout\; id="1"\; label="r\; N"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">r</figure-callout>}}_N^1\end{array}\right].$

Thus, (x, y) that can be obtained is the position of the target handset.

Example 3

In this embodiment, the position of the target mobile phone is calculated by using the TOA value and the AOA value of the arrival angle calculated by the onboard positioning measurement unit of each ship. Firstly, the TDOA value is calculated by using the TOA value, and then the TDOA value, the AOA value, the latitude and longitude information and the heading information are used for joint solution to obtain the location of the target mobile phone, so this embodiment may also be referred to as TDOA-AOA positioning algorithm, and the process is as follows:

step 301: the position service center sends positioning requests containing target mobile phone numbers to shipborne positioning measurement units of a plurality of ships through a ground satellite main station.

The positioning request sent by the position service center through the ground satellite main station is firstly received by each ship-borne satellite small station, and then the ship-borne satellite small station sends the positioning request to the ship-borne positioning measurement unit.

Step 302: after receiving the positioning request containing the target mobile phone number, the shipborne positioning measurement units of all ships forward the positioning request to the shipborne mobile base station of the ship.

Step 303: and the shipborne mobile base stations of all ships send dial testing requests to the target mobile phone.

Step 304: and after receiving the dial testing request, the target mobile phone sends the burst pulse with specific duration.

Step 305: and the positioning measurement unit of each ship calculates the TOA value and the AOA value of the arrival time of the target mobile phone relative to the shipborne mobile base station of the ship according to the burst pulse of the specific time length sent by the target mobile phone.

Step 306: and the positioning measurement unit of each ship sends the TOA value and the AOA value of the arrival angle of the arrival time and the AOA value of the arrival angle of the ship and the longitude and latitude, the course, the navigational speed, the rolling and pitching information of the ship to the shipborne satellite small station of the ship.

The positioning measurement unit and the shipborne satellite small station carry out data communication through a set protocol, and the set protocol format is the same as that in the step 106.

Step 307: and the shipborne satellite small station of the ship sends the arrival time TOA value, the arrival angle AOA value, the longitude and latitude, the course, the navigational speed, the rolling and pitching information of the ship to a position service center through a satellite link.

Step 308: and the position service center performs joint calculation by using the TOA value of the arrival time, the AOA value of the arrival angle, the longitude and latitude information and the course information returned by each ship to obtain the position of the target mobile phone.

First, the value of the time difference of arrival TDOA is calculated using the value of time of arrival TOA, which is the same as the calculation process of the value of time difference of arrival TDOA in step 208.

FIG. 5 is a schematic diagram of a TDOA-AOA location algorithm. In fig. 5, the target handset and the shipborne mobile base station BS_iIs alpha relative angle_iThe location and azimuth angle from the noisy hyperbola can be expressed as: r is_i1＝r_i-r₁+n_ri，

<math><mrow><msub><mi>&alpha;</mi><mi>i</mi></msub><mo>=</mo><mi>arctan</mi><mrow><mo>(</mo><mfrac><msub><mrow><mi>y</mi><mo>-</mo><mi>y</mi></mrow><mi>i</mi></msub><mrow><mi>x</mi><mo>-</mo><msub><mi>x</mi><mi>i</mi></msub></mrow></mfrac><mo>)</mo></mrow><mo>+</mo><msub><mi>n</mi><mi>&alpha;i</mi></msub><mo>-</mo><mo>-</mo><mo>-</mo><mrow><mo>(</mo><mn>14</mn><mo>)</mo></mrow></mrow></math>

Wherein n is_riAnd n_αiRespectively representing a distance measurement error and an angle measurement error.

Known from TDOA location algorithms:

$r_{\mathrm{<figure-callout\; id="1"\; label="r"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">r</figure-callout>}1}^2+2r_{i1}{\mathrm{<figure-callout\; id="1"\; label="r"\; filenames="HSA00000314397000021.png"\; state="\{\{state\}\}">r</figure-callout>}}_1=-2x_{i1}x-2y_{i1}y+K_i-K_1---\left(15\right)$

the orientation angle can be expressed as:

tan(α_i)x-y＝tan(α_i)x_i-y_i (16)

order to

M ship-borne mobile base stations participating in positioning have direction finding function, and the combination of formula (15) and formula (16) can establish the relation z_aThe system of linear equations of:

h＝G_αz_α (17)

wherein, <math><mrow><mi>h</mi><mo>=</mo><mfrac><mn>1</mn><mn>2</mn></mfrac><mfenced open='[' close=']'><mtable><mtr><mtd><msubsup><mi>r</mi><mn>21</mn><mn>2</mn></msubsup><mo>-</mo><msubsup><mi>K</mi><mn>2</mn><mn>2</mn></msubsup><mo>+</mo><msubsup><mi>K</mi><mn>1</mn><mn>2</mn></msubsup></mtd></mtr><mtr><mtd><msubsup><mi>r</mi><mn>31</mn><mn>2</mn></msubsup><mo>-</mo><msubsup><mi>K</mi><mn>3</mn><mn>2</mn></msubsup><mo>+</mo><msubsup><mi>K</mi><mn>1</mn><mn>2</mn></msubsup></mtd></mtr><mtr><mtd><mo>.</mo></mtd></mtr><mtr><mtd><mo>.</mo></mtd></mtr><mtr><mtd><mo>.</mo></mtd></mtr><mtr><mtd><msubsup><mi>r</mi><mrow><mi>N</mi><mn>1</mn></mrow><mn>2</mn></msubsup><mo>-</mo><msubsup><mi>K</mi><mi>N</mi><mn>2</mn></msubsup><mo>+</mo><msubsup><mi>K</mi><mn>1</mn><mn>2</mn></msubsup></mtd></mtr><mtr><mtd><msub><mi>x</mi><mn>1</mn></msub><mi>tan</mi><msub><mi>&alpha;</mi><mn>1</mn></msub><mo>-</mo><msub><mi>y</mi><mn>1</mn></msub></mtd></mtr><mtr><mtd><msub><mi>x</mi><mn>2</mn></msub><mi>tan</mi><msub><mi>&alpha;</mi><mn>2</mn></msub><mo>-</mo><msub><mi>y</mi><mn>2</mn></msub></mtd></mtr><mtr><mtd><mo>.</mo></mtd></mtr><mtr><mtd><mo>.</mo></mtd></mtr><mtr><mtd><mo>.</mo></mtd></mtr><mtr><mtd><msub><mi>x</mi><mi>M</mi></msub><mi>tan</mi><msub><mi>&alpha;</mi><mi>M</mi></msub><mo>-</mo><msub><mi>y</mi><mi>M</mi></msub></mtd></mtr></mtable></mfenced><mo>,</mo></mrow></math> <math><mrow><msub><mi>G</mi><mi>&alpha;</mi></msub><mo>=</mo><mo>-</mo><mfenced open='[' close=']'><mtable><mtr><mtd><msub><mi>x</mi><mn>21</mn></msub></mtd><mtd><msub><mi>y</mi><mn>21</mn></msub></mtd><mtd><msub><mi>r</mi><mn>21</mn></msub></mtd></mtr><mtr><mtd><msub><mi>x</mi><mn>31</mn></msub></mtd><mtd><msub><mi>y</mi><mn>31</mn></msub></mtd><mtd><msub><mi>r</mi><mn>31</mn></msub></mtd></mtr><mtr><mtd><mo>.</mo></mtd><mtd><mo>.</mo></mtd><mtd><mo>.</mo></mtd></mtr><mtr><mtd><mo>.</mo></mtd><mtd><mo>.</mo></mtd><mtd><mo>.</mo></mtd></mtr><mtr><mtd><mo>.</mo></mtd><mtd><mo>.</mo></mtd><mtd><mo>.</mo></mtd></mtr><mtr><mtd><msub><mi>x</mi><mrow><mi>N</mi><mn>1</mn></mrow></msub></mtd><mtd><msub><mi>y</mi><mrow><mi>N</mi><mn>1</mn></mrow></msub></mtd><mtd><msub><mi>r</mi><mrow><mi>N</mi><mn>1</mn></mrow></msub></mtd></mtr><mtr><mtd><mo>-</mo><mn>0.5</mn><mi>tan</mi><msub><mi>&alpha;</mi><mn>1</mn></msub></mtd><mtd><mn>0.5</mn></mtd><mtd><mn>0</mn></mtd></mtr><mtr><mtd><mo>-</mo><mn>0.5</mn><mi>tan</mi><msub><mi>&alpha;</mi><mn>2</mn></msub></mtd><mtd><mn>0.5</mn></mtd><mtd><mn>0</mn></mtd></mtr><mtr><mtd><mo>.</mo></mtd><mtd><mo>.</mo></mtd><mtd><mo>.</mo></mtd></mtr><mtr><mtd><mo>.</mo></mtd><mtd><mo>.</mo></mtd><mtd><mo>.</mo></mtd></mtr><mtr><mtd><mo>.</mo></mtd><mtd><mo>.</mo></mtd><mtd><mo>.</mo></mtd></mtr><mtr><mtd><mo>-</mo><mn>0.5</mn><mi>tan</mi><msub><mi>&alpha;</mi><mi>M</mi></msub></mtd><mtd><mn>0.5</mn></mtd><mtd><mn>0</mn></mtd></mtr></mtable></mfenced><mo>.</mo></mrow></math>

order to

Z corresponding to the real position of the target mobile phone_αThe error vector of the target handset can be expressed as:

<math><mrow><mi>&psi;</mi><mo>=</mo><mi>h</mi><mo>-</mo><msub><mi>G</mi><mi>&alpha;</mi></msub><msubsup><mi>z</mi><mi>&alpha;</mi><mn>0</mn></msubsup><mo>-</mo><mo>-</mo><mo>-</mo><mrow><mo>(</mo><mn>18</mn><mo>)</mo></mrow></mrow></math>

when the error of the AOA value of the arrival time is smaller, the method is characterized in that

The error in the time of arrival AOA value can be approximated as:

<math><mrow><msub><mi>&psi;</mi><msub><mi>&alpha;</mi><mi>i</mi></msub></msub><mo>=</mo><msub><mrow><mi>tan</mi><mi>&alpha;</mi></mrow><mi>i</mi></msub><mo>-</mo><mi>tan</mi><msubsup><mi>&alpha;</mi><mi>i</mi><mn>0</mn></msubsup><mo>&ap;</mo><mi>tan</mi><msub><mi>&delta;</mi><msub><mi>&alpha;</mi><mi>i</mi></msub></msub><mo>&ap;</mo><msub><mi>&delta;</mi><msub><mi>&alpha;</mi><mi>i</mi></msub></msub><mo>-</mo><mo>-</mo><mo>-</mo><mrow><mo>(</mo><mn>19</mn><mo>)</mo></mrow></mrow></math>

the estimated position of the target mobile phone is solved by using a weighted least square method to obtain:

<math><mrow><msub><mi>z</mi><mi>&alpha;</mi></msub><mo>=</mo><msup><mrow><mo>(</mo><msub><mi>G</mi><mi>&alpha;</mi></msub><msup><mi>&Psi;</mi><mrow><mo>-</mo><mn>1</mn></mrow></msup><msub><mi>G</mi><mi>&alpha;</mi></msub><mo>)</mo></mrow><mrow><mo>-</mo><mn>1</mn></mrow></msup><msubsup><mi>G</mi><mi>&alpha;</mi><mi>T</mi></msubsup><msup><mi>&Psi;</mi><mrow><mo>-</mo><mn>1</mn></mrow></msup><mi>h</mi><mo>-</mo><mo>-</mo><mo>-</mo><mrow><mo>(</mo><mn>20</mn><mo>)</mo></mrow></mrow></math>

where Ψ is a covariance matrix of the hybrid location joint error vector Ψ of the TDOA value and AOA value, which can be expressed as:

Ψ＝E[ψψ^T]＝BQB (21)

wherein,

if the time difference of arrival TDOA values and angle of arrival AOA values are independent of each other, the Q matrix can be expressed as:

<math><mrow><mi>Q</mi><mo>=</mo><mi>diag</mi><mo>{</mo><msubsup><mi>&sigma;</mi><mn>21</mn><mn>2</mn></msubsup><mo>,</mo><msubsup><mi>&sigma;</mi><mn>31</mn><mn>2</mn></msubsup><mo>,</mo><mo>&CenterDot;</mo><mo>&CenterDot;</mo><mo>&CenterDot;</mo><mo>,</mo><msubsup><mi>&sigma;</mi><mrow><mi>N</mi><mn>1</mn></mrow><mn>2</mn></msubsup><mo>,</mo><msubsup><mi>&sigma;</mi><msub><mi>&alpha;</mi><mn>1</mn></msub><mn>2</mn></msubsup><mo>,</mo><msubsup><mi>&sigma;</mi><msub><mi>&alpha;</mi><mn>2</mn></msub><mn>2</mn></msubsup><mo>&CenterDot;</mo><mo>&CenterDot;</mo><mo>&CenterDot;</mo><msubsup><mi>&sigma;</mi><msub><mi>&alpha;</mi><mi>M</mi></msub><mn>2</mn></msubsup><mo>}</mo><mo>-</mo><mo>-</mo><mo>-</mo><mrow><mo>(</mo><mn>22</mn><mo>)</mo></mrow></mrow></math>

wherein,

and

respectively, the respective variances of the time difference of arrival TDOA values and the angle of arrival AOA values.

Finally, according to z_p＝[x，y]^T，

The position (x, y) of the target handset can be found.

The resolving process in the above embodiments 1 to 3 is to convert the longitude and latitude of each ship to the plane coordinate and combine the direction finding information (TOA value and/or AOA value) to locate the target mobile phone. And after the plane coordinates of the target mobile phone are obtained, the coordinates can be converted back to longitude and latitude coordinates. At this time, because the direction-finding angle is an angle relative to the bow, the angle of the target mobile phone relative to the true north or the geomagnetic north can be known only after the angle of the bow is known. Therefore, if the plane coordinates of the target mobile phone need to be converted back to longitude and latitude coordinates, the heading information of each ship is indispensable. In addition, in the positioning algorithms of the target mobile phones given in embodiments 1 to 3, the accuracy of the TDOA-AOA positioning algorithm of embodiment 3 is higher than that of the TOA positioning algorithm of embodiment 1 and that of the TDOA positioning algorithm of embodiment 2. And the navigation speed, the rolling and the pitching information of each ship are used for monitoring the search and rescue ship by the position service center. After the position of the target mobile phone is calculated, the position of the target mobile phone can be stored in the position service center, and the position service center forwards the position of the target mobile phone to a related business department to command and implement search and rescue.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims (7)

1. A mobile phone positioning method based on a plurality of shipborne mobile base stations acquires measurement information of a target mobile phone through the shipborne mobile base stations and a shipborne positioning measurement unit, transmits the acquired measurement information and specific information of ships to which the shipborne mobile base stations belong to an information service center through a satellite link, and the information service center jointly calculates the position of the target mobile phone, and is characterized by comprising the following steps:

step 1: the method comprises the following steps that a position service center sends positioning requests containing target mobile phone numbers to shipborne positioning measurement units of a plurality of ships through a ground satellite master station;

step 2: after receiving the positioning request containing the target mobile phone number, the shipborne positioning measurement unit of each ship forwards the positioning request to the shipborne mobile base station of the ship;

and step 3: sending a dial testing request to a target mobile phone by the shipborne mobile base station of each ship;

and 4, step 4: after receiving the dial testing request, the target mobile phone sends a burst pulse with a specific duration;

and 5: the positioning measurement unit of each ship calculates the measurement information of the target mobile phone relative to the ship-borne mobile base station of the ship according to the burst pulse of the specific time length sent by the target mobile phone;

step 6: the positioning measurement unit of each ship sends the measurement information and the specific information of the ship to the shipborne satellite small station of the ship;

and 7: the shipborne satellite small station of the ship sends the measurement information and the specific information to a position service center through a satellite link;

and 8: and the position service center performs combined calculation on the measurement information and the specific information returned by each ship to obtain the position of the target mobile phone.

2. The method as claimed in claim 1, wherein the specific information includes latitude and longitude, heading, speed, roll and pitch information.

3. The method as claimed in claim 2, wherein the measurement information is time of arrival (TOA) values.

4. The method as claimed in claim 3, wherein the location service center performs joint solution on the measurement information and specific information returned by each ship to obtain the location of the target mobile phone, specifically, the location service center performs joint solution by using the TOA value, the latitude and longitude information, and the heading information returned by each ship to obtain the location of the target mobile phone.

5. The method as claimed in claim 3, wherein the location service center performs joint solution on the values returned by the ships to obtain the location of the target mobile phone, specifically, the location service center calculates the TDOA value according to the TOA value of the arrival time returned by the ships, and then performs joint solution by using the TDOA value, the longitude and latitude information, and the heading information to obtain the location of the target mobile phone.

6. The method as claimed in claim 2, wherein the measurement information is time of arrival (TOA) and angle of arrival (AOA).

7. The method as claimed in claim 6, wherein the location service center performs joint solution on the measurement information and specific information returned by each ship to obtain the estimated location of the target mobile phone, specifically, the location service center calculates TDOA value by using the TOA value of the arrival time returned by each ship, and performs joint solution by using TDOA value, AOA value of the arrival angle, latitude and longitude information and heading information to obtain the location of the target mobile phone.

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