Positioning system and method for mobile phone direct connection to satellite terminal based on phased array antenna

Abstract

The embodiment of the present invention discloses a positioning system and method for a mobile phone directly connected to a satellite terminal based on a phased array antenna, the system comprising a phased array antenna A, a receiver, a display and control processing device, a phased array antenna B, a phased array antenna C, a phased array antenna D, a low noise amplifier, and a power supply device for power supply, the phased array antenna A is connected to the display and control processing device via a receiver, and the phased array antenna B, the phased array antenna C, and the phased array antenna D are all connected to the display and control processing device via a low noise amplifier and a receiver. The present invention overcomes the problem that the traditional direction finding positioning technology cannot effectively capture and detect terminal signals when the mobile phone directly connected to the satellite terminal has low transmission power and fast beam scanning, and utilizes the advantages of the phased array antenna in beam control and antenna gain, and combines the advantages of amplitude comparison direction finding and arrival time difference direction finding, so as to effectively locate the mobile phone directly connected to the satellite terminal.

Description

Technical Field

[0001] The present invention relates to the field of radio monitoring and direction finding, and in particular to a positioning system and method for a mobile phone directly connected to a satellite terminal based on a phased array antenna. Background Art

[0002] In recent years, with the continuous development of mobile communications, payload platforms, rocket launches, and integrated circuit engineering technologies, low-orbit satellite constellations have developed rapidly, and mobile phone direct satellite communications based on low-orbit satellites have also emerged. It has the advantages of low latency and wide coverage, and has quickly become a hot spot in the current satellite communication field. However, this is bound to bring a series of challenges, including frequent interference and difficult supervision. Due to the low transmission power of mobile phone direct satellite terminals, traditional ground interference source search methods cannot effectively locate them, and there is currently no positioning method for mobile phone direct satellite terminals on the market. Therefore, it is urgent to study an effective means to deal with the challenges brought by mobile phone direct satellite connections.

[0003] Radio direction finding is the process of using the propagation characteristics of electromagnetic waves to determine the direction of the waves from unknown radiation sources using radio direction finding equipment. Its essence is to measure the angle between the normal directions of the wavefronts of the electromagnetic waves. Both amplitude-comparison direction finding and time-difference-of-arrival direction finding belong to the radio direction finding system.

[0004] The working principle of the amplitude-comparison direction finding system is to use the directional characteristics of the direction finding antenna array or the direction finding antenna to measure and calculate the amplitude according to the difference in the signal amplitude of the electromagnetic waves from different directions to determine the direction of the radiation source. The amplitude-comparison direction finding system is relatively simple, small in size, light in weight, and low in cost, but it has problems such as spacing error and polarization error, and its ability to resist wavefront distortion is limited.

[0005] The working principle of the arrival time difference direction finding system is to determine the direction of the electromagnetic wave by measuring the difference in the time when the electromagnetic wave arrives at different antennas during its travel. The characteristics of the arrival time difference direction finding system are high direction finding accuracy, high sensitivity, fast direction finding speed, insensitivity to polarization error, and low requirements for the direction finding site environment, but poor anti-interference performance.

[0006] Triangulation cross-positioning technology is the most widely used positioning method at present. It mainly uses multiple direction-finding antennas to obtain the incoming wave direction of the radiation source, and then cross-positions the multiple directions obtained to achieve passive positioning of the radiation source.

[0007] Phased array antenna is an antenna that changes the shape of the radiation pattern by controlling the feed amplitude or phase of each unit in the array antenna. Compared with the traditional method of using mechanical rotating antennas to achieve beam scanning, phased array antennas do not require mechanical steering but use computers to quickly control the feed amplitude and phase to change the direction of the maximum value of the antenna radiation pattern to achieve the purpose of beam scanning. And because each unit can be finely controlled, the phased array antenna can also form a very narrow main lobe beam. Therefore, phased array antennas are very suitable for tracking and monitoring low-orbit satellites and scanning and searching for mobile phones directly connected to satellite terminals. Summary of the invention

[0008] The technical problem to be solved by the embodiments of the present invention is to provide a positioning system and method for a mobile phone directly connected to a satellite terminal based on a phased array antenna, so as to overcome the problems of low terminal transmission power, fast beam movement, and difficulty in capturing and searching, thereby filling the gap in the current positioning means for mobile phones directly connected to satellite terminals.

[0009] In order to solve the above technical problems, an embodiment of the present invention proposes a positioning system for a mobile phone directly connected to a satellite terminal based on a phased array antenna, including a phased array antenna A, a receiver, a display and control processing device, a phased array antenna B, a phased array antenna C, a phased array antenna D, a low noise amplifier, and a power supply device for power supply. The phased array antenna A is connected to the display and control processing device through the receiver, and the phased array antenna B, the phased array antenna C, and the phased array antenna D are all connected to the display and control processing device through the low noise amplifier and the receiver.

[0010] The display and control processing device determines the type of business satellite according to the business of the mobile phone direct connection satellite, controls the phased array antenna A to track and monitor the satellite in real time, and determines whether there is a business signal according to the monitoring situation, and determines the working area of ​​the mobile phone direct connection satellite terminal; then sends the mobile phone direct connection satellite terminal uplink frequency band search command to the phased array antenna B, the phased array antenna C, and the phased array antenna D to perform the search task; after searching the uplink signal, the display and control processing device sends the uplink signal frequency information and the beam rapid scanning command to the phased array antenna B, the phased array antenna C, and the phased array antenna D, fixes its search frequency at the uplink frequency, and performs beam rapid scanning; finally, direction finding is performed separately according to the collected signal information, and the direction finding results are used to perform intersection positioning, and the positioning point is drawn on the map.

[0011] Accordingly, an embodiment of the present invention further provides a positioning method for a mobile phone directly connected to a satellite terminal based on a phased array antenna, comprising a monitoring step S1 and a positioning step S2, wherein the monitoring step S1 comprises:

[0012] Step S11: erecting a phased array antenna A at a high point in the selected area, and connecting the phased array antenna A, a receiver, a display control processing device, and a power supply device;

[0013] Step S12: judging whether the satellite of the mobile phone direct satellite service of the mobile phone direct satellite terminal is a geostationary orbit satellite or a low-orbit satellite;

[0014] Step S13: formulate a monitoring plan and control the phased array antenna A to track and monitor the satellite in real time;

[0015] Step S14: judging whether there is a service signal according to the monitoring situation, and determining the working area of ​​the mobile phone direct connection satellite terminal;

[0016] The positioning step S2 includes:

[0017] Step S21: within the satellite downlink service signal coverage area, taking the position of the phased array antenna A as the center of the circle, select three high points distributed in an acute triangle;

[0018] Step S22: Phased array antenna B, phased array antenna C, and phased array antenna D are respectively installed at three high points, and the antenna faces face the position where the phased array antenna A is located;

[0019] Step S23: Sending a mobile phone direct-connected satellite terminal uplink frequency band search command to the phased array antenna B, the phased array antenna C, and the phased array antenna D to perform the search task;

[0020] Step S24: After detecting the uplink signal, the display control processing device sends the uplink signal frequency information and the beam fast scanning instruction to the phased array antenna B, the phased array antenna C, and the phased array antenna D, fixes the search frequency at the uplink frequency, and performs beam fast scanning;

[0021] Step S25: Direction finding is performed respectively according to the collected signal information, and intersection positioning is performed using the direction finding results, and positioning points are drawn on the map.

[0022] The beneficial effects of the present invention are as follows: the present invention effectively fills the gap in the positioning of mobile phone direct-connected satellite terminals, as there is no positioning solution for such terminals on the market at present; the present invention overcomes the problem that traditional direction-finding positioning technology cannot effectively capture and detect terminal signals when the mobile phone direct-connected satellite terminals have low transmission power and fast beam scanning, and utilizes the advantages of phased array antennas in beam control and antenna gain, and combines the advantages of amplitude ratio direction finding and arrival time difference direction finding, so as to effectively locate mobile phone direct-connected satellite terminals. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of a positioning system for a mobile phone directly connected to a satellite terminal based on a phased array antenna according to an embodiment of the present invention.

[0024] Figure 2 4 is a flow chart of the monitoring steps of an embodiment of the present invention.

[0025] Figure 3 It is a flowchart of the positioning step of an embodiment of the present invention.

[0026] Figure 4 Schematic diagram of the structure of the phased array antenna A according to an embodiment of the present invention.

[0027] Figure 5 It is a schematic diagram of the structures of the phased array antenna B, the phased array antenna C, and the phased array antenna D according to an embodiment of the present invention.

[0028] Figure 6 It is a schematic diagram of satellite downlink signal monitoring according to an embodiment of the present invention.

[0029] Figure 7 The invention is a schematic diagram of direction finding and positioning of a mobile phone directly connected to a satellite terminal in an amplitude comparison direction finding system according to an embodiment of the present invention.

[0030] Figure 8 The present invention is a schematic diagram of direction finding and positioning of a mobile phone directly connected to a satellite terminal in a time difference direction finding system according to an embodiment of the present invention.

[0031] Fig. 9 It is a schematic diagram of the finished product structure in the PCB manufacturing process of an embodiment of the present invention. DETAILED DESCRIPTION

[0032] It should be noted that, in the absence of conflict, the embodiments in the present application and the features in the embodiments may be combined with each other. The present invention is further described in detail below in conjunction with the drawings and specific embodiments.

[0033] In the embodiments of the present invention, if there are directional indications (such as up, down, left, right, front, back, etc.), they are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0034] In addition, in the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features.

[0035] Please refer to Figure 1 The positioning system for a mobile phone directly connected to a satellite terminal based on a phased array antenna in an embodiment of the present invention includes a phased array antenna A, a receiver, a display and control processing device, a phased array antenna B, a phased array antenna C, a phased array antenna D, a low noise amplifier, and a power supply device for powering.

[0036] Please refer to Figure 4, the phased array antenna A is connected to the display control processing device through the receiver. The phased array antenna A is used to monitor the satellite downlink service signal in real time, including the antenna array, beam synthesis module, down conversion module, beam control module, GPS module and power supply module.

[0037] Please refer to Figure 5 Phased array antenna B, phased array antenna C, and phased array antenna D are all connected to the display and control processing equipment through low noise amplifiers and receivers. The display and control processing equipment is equipped with a satellite downlink service monitoring software system and a direction finding and positioning software system. Phased array antenna B, phased array antenna C, and phased array antenna D are used for direction finding and triangulation cross positioning of mobile phones directly connected to satellite terminals. The structures of the three antennas are the same, including antenna arrays, beam synthesis modules, down-conversion modules, beam control modules, GPS modules, and power supply modules.

[0038] The four phased array antennas of the present invention should have at least the following functions:

[0039] (1) It can form an independent beam pointing;

[0040] (2) Supports dual circular polarization / dual linear polarization working modes and can switch quickly;

[0041] (3) Integrated down-conversion function, adjustable local oscillator frequency;

[0042] (4) Integrated real-time temperature monitoring and power-on self-test functions;

[0043] (5) Integrated GPS antenna module;

[0044] (6) Integrated low-profile radome;

[0045] (7) Having alarm function;

[0046] (8) It has its own power modulation function to ensure stable DC power supply for internal devices. External power supply can be provided by batteries or conversion power supply.

[0047] (9) It must be suitable for portable scenarios.

[0048] The receiver is used to receive radio signals and select the required signals, output the information transmitted by the radio signals at the output end of the receiver, and configure the mobile communication module.

[0049] Please refer to Figure 6 The display and control processing equipment determines the type of business satellite according to the business of the mobile phone directly connected to the satellite, sets parameters according to the type of business satellite, formulates a monitoring plan, controls the phased array antenna A to track and monitor the satellite in real time, and determines whether there is a business signal according to the monitoring situation, and determines the working area of ​​the mobile phone directly connected to the satellite terminal.

[0050] The mobile phone direct satellite terminal service currently uses two types of orbital satellites, namely geostationary orbit satellites and low-orbit satellites. The satellite tracking strategies for these two types of satellites are different. Geostationary orbit satellites can be tracked based on orbital information and the longitude and latitude of the monitoring location; low-orbit satellites need to predict the satellite transit time and transit trajectory based on the corresponding satellite ephemeris, and then use the phased array antenna beam fast switching capability to accurately track the satellite in real time.

[0051] For the monitoring plan of geostationary satellites, the monitoring software solves the beam pointing of the current array according to the parameter settings and sends it to the antenna array. For low-orbit satellites, it is necessary to calculate the position and speed of the satellite based on the low-orbit satellite ephemeris data combined with the SGP4 model prediction technology to obtain the satellite transit time and trajectory, and then calculate the beam pointing during the satellite transit based on the above information. Send it to the antenna array to complete the real-time tracking and signal reception of the low-orbit satellite. The parameter settings of the monitoring plan are recommended as shown in Table 1:

[0052] Table 1

[0053]

[0054] The business signal is determined by the correlation detection method. The noise floor database template is established by repeatedly measuring the noise floor monitoring situation in the monitoring frequency band when there is no business signal. During the satellite transit process, the monitored signal spectrum is compared with the noise floor database template to quickly determine whether there is a business signal.

[0055] After determining the working area of ​​the mobile phone direct-connected satellite terminal, the terminal enters the direction finding and positioning phase, which is implemented by phased array antenna B, phased array antenna C, phased array antenna D, low noise amplifier, receiver, display control processing equipment and power supply equipment.

[0056] The display and control processing device sends a mobile phone direct satellite terminal uplink frequency band search command to the phased array antenna B, phased array antenna C, and phased array antenna D to perform the search task. In the current environment, the background noise monitoring situation in the monitoring frequency band can be measured multiple times in advance to establish a background noise template. During the search process, it is compared with the background noise template, and once a new signal is found, it is identified as a terminal uplink signal. In particular, during the search process, the phased array antenna quickly performs a cyclic scan within the controllable range of its beam pointing, and the polarization mode is also switched at the beginning of each beam scanning cycle. After the uplink signal is detected, the display and control processing device sends the uplink signal frequency information and the beam fast scanning command to the phased array antenna B, phased array antenna C, and phased array antenna D, fixes its search frequency to the uplink frequency, and performs a beam fast scan; finally, direction finding is performed separately according to the collected signal information, and the direction finding results are used to perform intersection positioning, and the positioning point is drawn on the map.

[0057] The display and control processing equipment is mainly divided into two parts. One part is mainly for real-time monitoring of downlink service signals from satellite to mobile terminals. Once the service signal is detected, it is determined that there is a mobile phone directly connected to the satellite terminal in the area, and the positioning range of the terminal is reduced. This part of the display and control processing equipment should include at least the following functions:

[0058] (1) Ability to predict satellite transit time and trajectory at different elevation angles based on ephemeris files;

[0059] (2) Ability to formulate monitoring mission plans based on ephemeris prediction results;

[0060] (3) Ability to control antenna to track satellite according to monitoring mission plan;

[0061] (4) Ability to display spectrum in real time during satellite transit;

[0062] (5) Ability to generate an alarm upon detecting a downlink service signal.

[0063] The other part of the display and control processing equipment uses multiple phased array antennas (at least 3 sets) set up at high places in a specific area to perform frequency search and beam scanning direction finding on the mobile phone directly connected to the satellite terminal, and then uses the direction finding results of multiple antennas to perform intersection positioning, and finally realizes the positioning of the mobile phone directly connected to the satellite terminal. This part of the display and control processing equipment should include at least the following functions:

[0064] (1) Ability to display antenna location on a map in real time;

[0065] (2) Ability to control the antenna to perform beam scanning in a certain frequency band;

[0066] (3) Ability to control the antenna to receive signals at a certain frequency simultaneously;

[0067] (4) Ability to control the receiver to collect signals at a certain frequency simultaneously;

[0068] (5) Ability to perform time difference direction finding on the returned signal;

[0069] (6) Ability to use time difference lines for intersection positioning and draw positioning points on the map;

[0070] (7) Ability to draw positioning tracks on a map at set time intervals;

[0071] (8) Ability to optimize positioning trajectory based on road network information and predict terminal travel route.

[0072] The power supply equipment is used to provide power to the above-mentioned devices.

[0073] As an implementation mode, the display control processing device includes:

[0074] Antenna control module: used to control phased array antenna A, phased array antenna B, phased array antenna C, and phased array antenna D;

[0075] Monitoring plan formulation module: set parameters and formulate monitoring plans according to the business satellite type;

[0076] Ephemeris prediction module: predicts the satellite transit time and transit trajectory based on the corresponding satellite ephemeris;

[0077] Satellite tracking module: controls the antenna to track satellites according to the monitoring plan;

[0078] Spectrum display module: displays the spectrum in real time during satellite transit;

[0079] Direction finding algorithm module: It uses the combination of amplitude comparison direction finding and time difference direction finding method to calculate;

[0080] Direction finding and positioning module: Based on the collected signal information, the time difference between the signals reaching the three antennas, namely, phased array antenna B, phased array antenna C, and phased array antenna D, is analyzed, three time difference lines are calculated, and the three time difference lines are intersected to obtain the positioning point of the mobile phone directly connected to the satellite terminal;

[0081] Map module: draw positioning points on the map;

[0082] Display module: converts spectrum information and map information into visible images or text information for display.

[0083] As an implementation method, within the coverage area of ​​the satellite downlink service signal, with the position of the phased array antenna A as the center of the circle, three high points in an acute triangle distribution are selected, and the phased array antenna B, the phased array antenna C, and the phased array antenna D are respectively set up at the three high points, and the antenna faces face the position of the phased array antenna A. The three phased array antennas used for direction finding and positioning, the phased array antenna B, the phased array antenna C, and the phased array antenna D, should try to meet the distribution mode of the acute triangle. This is because under the same direction error, the area outside the triangle area will cause a greater positioning accuracy error, and this distribution method can better ensure that the signal power received by each antenna is close, and the power received by a certain antenna is too small, resulting in a large direction finding error, which affects the positioning accuracy. In order to establish a connection with the satellite for communication, the mobile phone direct satellite terminal generally chooses an open place. Therefore, on the basis of facing the direction of the phased array antenna A, the three phased array antennas are preferably facing the open area to increase the probability of receiving the terminal uplink signal.

[0084] As an implementation method, the display and control processing device compares the monitored signal spectrum with the background noise database template during the satellite transit process, and determines whether there is a service signal based on the comparison result; the background noise database template is established by repeatedly measuring the background noise monitoring conditions in the monitoring frequency band when there is no service signal.

[0085] Preferably, the display and control processing device uses a combination of amplitude comparison direction finding and time difference direction finding to perform direction finding. Figure 7 In the more complex electromagnetic environment of the urban area, the amplitude comparison direction finding system is selected, and in the more open environment, the time difference direction finding system is selected. Please refer to Figure 8 When using time difference direction finding, it is necessary to ensure that the three antennas collect signals at the same time. The direction finding positioning software analyzes the time difference between the signals reaching the three antennas based on the collected signal information, calculates three time difference lines, and intersects these three time difference lines to obtain the positioning point of the mobile phone directly connected to the satellite terminal.

[0086] As an implementation method, if the mobile phone directly connected to the satellite terminal is in a moving state, the display and control processing device draws a positioning trajectory every 1 second and compares it with the road network information to predict the route of the mobile phone directly connected to the satellite terminal and improve the positioning accuracy.

[0087] Please refer to Figure 2-3 The positioning method of a mobile phone directly connected to a satellite terminal based on a phased array antenna in an embodiment of the present invention includes a monitoring step S1 for confirming the use area of ​​the mobile phone directly connected to the satellite terminal and a positioning step S2 for performing direction finding and positioning on the mobile phone directly connected to the satellite terminal.

[0088] The monitoring step S1 includes steps S11 to S14.

[0089] Step S11: Set up the phased array antenna A at a high place in the selected area. Ensure that the terrain in front of the antenna is open and there should be no tall obstacles such as trees, chimneys, water towers, buildings, metal reflectors, overhead power lines, and electric poles in the clear area. Connect the phased array antenna A, receiver, display and control processing equipment, and power supply equipment.

[0090] Step S12: According to the mobile phone direct satellite service of the mobile phone direct satellite terminal, determine whether the satellite of the service belongs to a geostationary orbit satellite or a low-orbit satellite. The mobile phone direct satellite terminal service currently uses two types of orbital satellites, namely geostationary orbit satellites and low-orbit satellites. For satellites in these two orbits, the satellite following strategies are different. Geostationary orbit satellites can be followed only based on the orbital position information and the longitude and latitude of the monitoring location, and the beam of the phased array antenna does not need to be adjusted; low-orbit satellites need to predict the satellite transit time and transit trajectory based on the corresponding satellite ephemeris, and then use the phased array antenna beam The ability to quickly switch the ability to accurately track the satellite in real time.

[0091] Step S13: Formulate a monitoring plan and control the phased array antenna A to track and monitor the satellite in real time. For the monitoring plan of geostationary satellites, the monitoring software solves the beam pointing of the current array according to the parameter settings and sends it to the antenna array. For low-orbit satellites, it is necessary to calculate the position and speed of the satellite based on the low-orbit satellite ephemeris data combined with the SGP4 model prediction technology to obtain the satellite transit time and trajectory, and then calculate the beam pointing during the satellite transit based on the above information. Send it to the antenna array to complete the real-time tracking and signal reception of the low-orbit satellite.

[0092] Step S14: According to the monitoring situation, determine whether there is a service signal and determine the working area of ​​the mobile phone directly connected to the satellite terminal. The service signal is determined by the correlation detection method. By repeatedly measuring the background noise monitoring situation in the monitoring frequency band when there is no service signal, a background noise database template is established. During the satellite transit process, the monitored signal spectrum is compared with the background noise database template to quickly determine whether there is a service signal. On the one hand, this method uses a computer to complete the judgment, effectively reducing the errors caused by manual judgment; on the other hand, it can also establish corresponding background noise database templates according to different satellites, so that when executing the same satellite mission in the future, there is no need to re-establish the template, thereby improving work efficiency.

[0093] After the working area of ​​the mobile phone directly connected to the satellite terminal is determined, the positioning step S2 is entered.

[0094] The positioning step S2 includes steps S21 to S25.

[0095] Step S21: Within the satellite downlink service signal coverage area, take the position of the phased array antenna A as the center of the circle, select three high points, try to ensure that the selected positions are distributed in an acute triangle, and if possible, try to distribute in an equilateral triangle. This distribution method preferentially assumes that the terminal is within this triangular area, reduces the consideration of too many additional factors when selecting points, and improves the efficiency of point distribution. And if the terminal is within the triangular area, under the same direction error, the area outside the triangular area will cause a greater positioning accuracy error. At the same time, this distribution can better ensure that the signal power received by each antenna is close, and the power received by a certain antenna is too small, resulting in excessive direction finding error, affecting positioning accuracy. For point distribution suggestions, see Fig. 9 .

[0096] Step S22: Phased array antenna B, phased array antenna C, and phased array antenna D are respectively set up at three high points, and the antenna faces face the position of phased array antenna A. This orientation is based on the assumption of step S21, and the mobile phone direct satellite terminal generally chooses an open place in order to establish a connection with the satellite for communication. Therefore, the three phased array antennas are preferably oriented toward an open place on the basis of facing one direction of the phased array antenna, so as to increase the probability of receiving the terminal uplink signal.

[0097] Step S23: Send a mobile phone direct-to-satellite terminal uplink frequency band search command to phased array antenna B, phased array antenna C, and phased array antenna D to perform the search task. In the current environment, the background noise monitoring situation in the monitoring frequency band can be measured multiple times in advance to establish a background noise template. During the search process, it is compared with the background noise template, and once a new signal is found, it is identified as a terminal uplink signal. In particular, during the search process, the phased array antenna quickly performs a cyclic scan within the controllable range of its beam pointing, and the polarization mode must also be switched at the beginning of each beam scanning cycle. In this way, not only can the signal be quickly searched, but also the polarization matching with the signal can be completed in the shortest possible time, thereby increasing the probability of capturing the terminal uplink signal.

[0098] Step S24: After detecting the uplink signal, the display control processing device sends the uplink signal frequency information and the beam rapid scanning instruction to the phased array antenna B, the phased array antenna C, and the phased array antenna D, fixes its search frequency at the uplink frequency, and performs a beam rapid scanning.

[0099] Step S25: Direction finding is performed respectively according to the collected signal information, and the direction finding results are applied to perform intersection positioning, and the positioning points are drawn on the map. After the three antennas of phased array antenna B, phased array antenna C, and phased array antenna D can all receive the uplink signal of the terminal, the uplink signal is collected at the same time. The display and control processing equipment performs direction finding respectively according to the collected signal information, and applies the direction finding results to perform intersection positioning, and draws the positioning points on the map. The direction finding system adopts a combination of amplitude comparison direction finding and time difference direction finding. In the more complex electromagnetic environment in the urban area, the amplitude comparison direction finding system is selected, and the time difference direction finding system is selected in a relatively open environment. This is because the complex urban environment may cause multipath effects, and the multipath effect will cause the error of the positioning accuracy of the time difference direction finding system to increase. However, in an open environment, the time difference direction finding system has a greater advantage. Generally, the terminal will keep moving, which will cause the antenna to receive the terminal signal. The receiving power is small and the polarization is difficult to match. The time difference direction finding system has high sensitivity and low sensitivity to the polarization mode of the signal. Therefore, in view of the above circumstances, it is more common to use the time difference direction finding system in an open environment. When using time difference direction finding, it is necessary to ensure that the three antennas collect signals at the same time. The direction finding positioning software analyzes the time difference between the signals reaching the three antennas based on the collected signal information, calculates three time difference lines, and intersects these three time difference lines to obtain the positioning point of the mobile phone directly connected to the satellite terminal.

[0100] As an implementation method, if the mobile phone directly connected to the satellite terminal is in a moving state, it can be set to draw a positioning trajectory every 1 second and compare it with the road network information to predict the terminal's route and improve the positioning accuracy.

[0101] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A positioning system for a mobile phone directly connected to a satellite terminal based on a phased array antenna, characterized in that: It includes phased array antenna A, receiver, display and control processing equipment, phased array antenna B, phased array antenna C, phased array antenna D, low noise amplifier and power supply equipment for power supply. Phased array antenna A is connected to the display and control processing equipment through the receiver, and phased array antenna B, phased array antenna C and phased array antenna D are all connected to the display and control processing equipment through the low noise amplifier and receiver. The display and control processing device determines the type of service satellite according to the service of the mobile phone directly connected to the satellite, controls the phased array antenna A to track and monitor the satellite in real time, determines whether there is a service signal according to the monitoring situation, and determines the working area of ​​the mobile phone directly connected to the satellite terminal; then sends the mobile phone directly connected to the satellite terminal uplink frequency band search command to the phased array antenna B, the phased array antenna C, and the phased array antenna D to perform the search task; after the uplink signal is detected, the display and control processing device sends the uplink signal frequency point information and the beam fast scanning command to the phased array antenna B, the phased array antenna C, and the phased array antenna D, fixes its search frequency to the uplink frequency, and performs beam fast scanning; finally, direction finding is performed respectively according to the collected signal information, and the direction finding result is used to perform intersection positioning, and the positioning point is drawn on the map; Display and control processing equipment includes: Antenna control module: used to control phased array antenna A, phased array antenna B, phased array antenna C, and phased array antenna D; Monitoring plan formulation module: set parameters and formulate monitoring plans according to the business satellite type; Ephemeris prediction module: predicts the satellite transit time and transit trajectory based on the corresponding satellite ephemeris; Satellite tracking module: controls the antenna to track satellites according to the monitoring plan; Spectrum display module: displays the spectrum in real time during satellite transit; Direction finding algorithm module: It uses the combination of amplitude comparison direction finding and time difference direction finding method to calculate; Direction finding and positioning module: Based on the collected signal information, the time difference between the signals reaching the three antennas, namely, phased array antenna B, phased array antenna C, and phased array antenna D, is analyzed, three time difference lines are calculated, and the three time difference lines are intersected to obtain the positioning point of the mobile phone directly connected to the satellite terminal; Map module: draw positioning points on the map; Display module: converts spectrum information and map information into visible images or text information for display.

2. The positioning system for mobile phones directly connected to satellite terminals based on phased array antennas as claimed in claim 1, characterized in that: In the satellite downlink service signal coverage area, with the position of phased array antenna A as the center of the circle, three high points distributed in an acute-angle triangle are selected, and phased array antenna B, phased array antenna C, and phased array antenna D are respectively installed at the three high points, and the antenna faces face the position of phased array antenna A.

3. The positioning system for mobile phones directly connected to satellite terminals based on phased array antennas as claimed in claim 1, characterized in that: During the satellite transit, the display and control processing equipment compares the monitored signal spectrum with the background noise database template, and determines whether there is a service signal based on the comparison result; the background noise database template is established by repeatedly measuring the background noise monitoring situation in the monitoring frequency band when there is no service signal.

4. The positioning system for mobile phones directly connected to satellite terminals based on phased array antennas as claimed in claim 1, characterized in that: If the mobile phone directly connected to the satellite terminal is in a moving state, the display and control processing equipment will draw a positioning trajectory every 1 second and compare it with the road network information to predict the route of the mobile phone directly connected to the satellite terminal and improve the positioning accuracy.

5. A positioning method for a mobile phone directly connected to a satellite terminal based on a phased array antenna, characterized in that: Applied to the positioning system of a mobile phone directly connected to a satellite terminal based on a phased array antenna as described in any one of claims 1 to 4, the positioning method includes a monitoring step S1 and a positioning step S2, and the monitoring step S1 includes: Step S11: erecting a phased array antenna A at a high point in the selected area, and connecting the phased array antenna A, a receiver, a display control processing device, and a power supply device; Step S12: judging whether the satellite of the mobile phone direct satellite service of the mobile phone direct satellite terminal is a geostationary orbit satellite or a low-orbit satellite; Step S13: formulate a monitoring plan and control the phased array antenna A to track and monitor the satellite in real time; Step S14: judging whether there is a service signal according to the monitoring situation, and determining the working area of ​​the mobile phone direct connection satellite terminal; The positioning step S2 includes: Step S21: within the satellite downlink service signal coverage area, taking the position of the phased array antenna A as the center of the circle, select three high points distributed in an acute triangle; Step S22: Phased array antenna B, phased array antenna C, and phased array antenna D are respectively installed at three high points, and the antenna faces face the position where the phased array antenna A is located; Step S23: Sending a mobile phone direct-connected satellite terminal uplink frequency band search command to the phased array antenna B, the phased array antenna C, and the phased array antenna D to perform the search task; Step S24: After detecting the uplink signal, the display control processing device sends the uplink signal frequency information and the beam fast scanning instruction to the phased array antenna B, the phased array antenna C, and the phased array antenna D, fixes the search frequency at the uplink frequency, and performs beam fast scanning; Step S25: Direction finding is performed respectively according to the collected signal information, and intersection positioning is performed using the direction finding results, and positioning points are drawn on the map.

6. The method for positioning a mobile phone directly connected to a satellite terminal based on a phased array antenna as claimed in claim 5, characterized in that: In step S13, if the satellite determined in step S12 is a geostationary satellite, the satellite is tracked only according to the orbit information and the longitude and latitude of the monitoring location, and the beam of the phased array antenna A is not adjusted; If it is a low-orbit satellite, the satellite transit time and transit trajectory are predicted based on the corresponding satellite ephemeris, and then the satellite is accurately tracked in real time by utilizing the rapid beam switching capability of the phased array antenna A.

7. The method for positioning a mobile phone directly connected to a satellite terminal based on a phased array antenna as claimed in claim 5, characterized in that: In step S14, a correlation detection method is used to compare the monitored signal spectrum with the background noise database template during the satellite transit process to determine whether there is a service signal; wherein the background noise database template is established by repeatedly measuring the background noise monitoring conditions in the monitoring frequency band when there is no service signal.

8. The method for positioning a mobile phone directly connected to a satellite terminal based on a phased array antenna as claimed in claim 5, characterized in that: In step S23, during the search process, the detected signal spectrum is compared with the background noise template. If a new signal is found, it is identified as the uplink signal of the mobile phone directly connected to the satellite terminal. The background noise template is established by measuring the background noise monitoring conditions in the monitoring frequency band multiple times under the current environment.

9. The method for positioning a mobile phone directly connected to a satellite terminal based on a phased array antenna as claimed in claim 5, characterized in that: In step S25, direction finding is performed by combining amplitude comparison direction finding and time difference direction finding. Amplitude comparison direction finding is selected in a complex environment, and time difference direction finding is selected in an open environment. Among them, when the time difference direction finding method is adopted, signals are collected simultaneously by phased array antenna B, phased array antenna C, and phased array antenna D. According to the collected signal information, the pairwise time difference of the signals arriving at the three antennas is analyzed, and the three time difference lines are calculated. The three time difference lines are intersected to obtain the positioning point of the mobile phone directly connected to the satellite terminal.

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