ATG cell selection method and device and medium

Abstract

The invention provides an ATG cell selection method and device and a medium, relates to the technical field of communication, and is used for solving the problem of how to realize efficient cell selection on the premise of suppressing interference in ground-air communication, and the method comprises the following steps: obtaining X ATG base station cells closest to an ATG airborne terminal at present; according to the current maximum airborne antenna gain of the ATG airborne terminal to the X ATG base station cells, current received signal strength estimation values of the ATG airborne terminal to the X ATG base station cells are calculated; selecting N ATG base station cells with the maximum estimated value of the current received signal strength; according to the current maximum airborne antenna gain of the ATG airborne terminal to the N ATG base station cells, the current received signal strength actual values of the ATG airborne terminal to the N ATG base station cells are measured; and selecting a new access cell of the ATG airborne terminal according to the actual value of the current received signal strength.

Description

Technical Field

[0001] The present invention at least relates to the field of ground-to-air communication technology, and in particular to an ATG cell selection method, an ATG cell selection device, and a computer-readable storage medium. Background Art

[0002] In recent years, with the liberalization of airborne communications, the use of ground base stations to cover aircraft routes to achieve ground-to-airborne communications (Air to ground, ATG) has become a research hotspot. Compared with satellite airborne communications, the ATG solution has the characteristics of large system capacity, fast service transmission rate, good transmission delay performance, and small system investment. In some cases, the ATG solution is customized and developed based on the existing 4G / 5G (fourth / fifth generation mobile communication technology, 4 / 5th Generation Mobile Communication Technology) base stations, with continuous coverage along the route. Airborne terminals and ground base stations are deeply customized to adapt to ground-to-air scenarios. The ground base station antennas are customized to supplement the blind spots at the top of the airspace to ensure link continuity.

[0003] One of the core aspects of the ATG technical solution is frequency resource acquisition. At present, the domestic method mainly uses the method of reusing the ground cellular public network frequency. There are two main frequency resources. One is to use the cellular network deployed non-continuously on the ground, and use spatial isolation to reduce the mutual influence between systems to achieve coexistence between ATG and the ground network; the other is to use dedicated frequencies (such as civil aviation dedicated frequencies) to carry the key link control of the system, and reuse the ground cellular network for business channels. These two solutions use spatial isolation and other low-interference frequencies to carry user links or control links to achieve coexistence of ground-to-air systems.

[0004] With the development of services and applications, the coverage of ground cellular networks has gradually expanded, and the site density has increased, making it more difficult to achieve coexistence using spatial isolation. In addition, due to the large number of ground base stations, the aggregated signals of the air side lobes of multiple base station antennas form strong interference at the flight path, which can reach -77dBm to -93dBm in actual measurements, 30dB to 40dB higher than the terminal noise floor. That is, the ground network causes strong co-frequency interference to the air, affecting the continuity of the air link, which may

[0005] The following questions arise:

[0006] 1) ATG and the ground cellular network with non-continuous coverage use a coexistence solution of spatial isolation. In the future, when the development of ground cellular services requires large-scale continuous networking, it will be difficult to meet the spatial isolation requirements required for the coexistence of ATG and the ground, resulting in mutual interference and affecting the link quality and user experience of the two networks.

[0007] 2) ATG uses other dedicated frequencies to assist in achieving coexistence with cellular networks. However, there is a risk of dedicated frequencies being reclaimed or mutual interference with dedicated frequency users. For example, the use of dedicated frequencies on border routes poses a risk of interference with neighboring countries.

[0008] When the ATG system reuses the ground network frequency, in order to suppress the interference signal from the ground network, it is necessary to adopt a solution to maintain the directional reception signal of the airborne terminal, that is, always keep the shaping state of the airborne antenna so that the main lobe points to the ATG service cell to reduce the co-frequency interference in other directions. However, during the process of airborne terminal access and switching cells, it is still necessary to control the omnidirectional measurement of the channel. Therefore, how to realize the access and switching process of the airborne terminal while maintaining directional reception of the airborne terminal is an urgent problem to be solved. Summary of the invention

[0009] The technical problem to be solved by the present invention is to provide an ATG cell selection method, an ATG cell selection device and a computer-readable storage medium in view of the above-mentioned shortcomings, so as to solve the problem of how to achieve efficient cell selection under the premise of suppressing interference in ground-to-air communication.

[0010] In a first aspect, the present invention provides a method for selecting an ATG cell in ground-to-air communication.

[0011] The law includes:

[0012] Obtain the X ATG base station cells that are currently closest to the ATG airborne terminal;

[0013] Calculate the estimated values ​​of the current received signal strengths of the ATG airborne terminal for the X ATG base station cells according to the current maximum airborne antenna gains of the ATG airborne terminal for the X ATG base station cells;

[0014] Select N ATG base station cells with the largest estimated received signal strength values;

[0015] According to the current maximum airborne antenna gain of the ATG airborne terminal to the N ATG base station cells, the actual value of the current received signal strength of the ATG airborne terminal to the N ATG base station cells is measured;

[0016] A new access cell for the ATG airborne terminal is selected according to the actual value of the current received signal strength.

[0017] In one implementation, calculating the estimated value of the current received signal strength of the ATG airborne terminal for the X ATG base station cells according to the current maximum airborne antenna gain of the ATG airborne terminal for the X ATG base station cells respectively includes:

[0018] According to formula (1), the estimated value Pr of the current received signal strength of the ATG airborne terminal to X ATG base station cells is calculated respectively: i:

[0019] Pr i =Pt i +Gt i +Gr i -PL i

[0020] Among them, Pt i is the transmission power of the i-th ATG base station cell; Gt i Gr is the current cell antenna gain of the i-th ATG base station cell to the ATG airborne terminal; i is the current maximum airborne antenna gain of the ATG airborne terminal to the i-th ATG base station cell; PL i is the path loss of the ATG airborne terminal to the i-th ATG base station cell.

[0021] In one implementation, obtaining the X ATG base station cells that are currently closest to the ATG airborne terminal includes:

[0022] Obtain the current flight position of the ATG airborne terminal and the base station position of the ground ATG base station;

[0023] Obtaining several ground ATG base stations located within a preset distance range of the current flight position;

[0024] Obtaining cell antenna directions of X ATG base station cells and respective X ATG base station cells of the plurality of ground ATG base stations;

[0025] Obtain the airborne antenna gain table of the ATG airborne terminal, the cell transmission power and cell antenna gain table of each of the X ATG base station cells, and the ATG operating frequency.

[0026] In one embodiment, the method is performed by an ATG onboard terminal;

[0027] The current flight position is obtained in real time through the bus protocol connected to the aircraft;

[0028] The base station location, cell antenna direction, airborne antenna gain table, cell transmission power, cell antenna gain table, and ATG operating frequency are all pre-stored in the airborne terminal.

[0029] In one embodiment, the current received signal strength estimation value Pr of the ATG airborne terminal to X ATG base station cells is calculated according to formula (1): i Previously, the method also included:

[0030] According to the current flight position, the base station position and the cell antenna direction, the first angle between the cell antenna direction of the i-th ATG base station cell and the ATG airborne terminal is obtained, and the cell antenna gain table of the i-th ATG base station cell is queried according to the first angle to obtain Gt i ;

[0031] According to the current flight position and the base station position, the second angle of the airborne antenna direction of the ATG airborne terminal aligning with the i-th ATG base station cell is obtained, and the airborne antenna gain table is queried according to the second angle to obtain Gr i ;

[0032] According to formula (2), the path loss PL of the ATG airborne terminal to the i-th ATG base station cell is calculated: i :

[0033] PL i =32.4+20*logD i +20*logF i

[0034] Among them, D i is the physical distance between the ATG airborne terminal and the ground ATG base station where the i-th ATG base station cell is located, calculated based on the current flight position and base station position; F i is the ATG operating frequency.

[0035] In one implementation, selecting N ATG base station cells with maximum current received signal strength estimation values ​​includes:

[0036] The X ATG base station cells are first sorted in descending order according to the current received signal strength estimation values, and the first N ATG base station cells after the first sorting are selected, where N is a value preset between 3-6.

[0037] In one implementation, measuring the actual value of the current received signal strength of the ATG airborne terminal to the N ATG base station cells according to the current maximum airborne antenna gain of the ATG airborne terminal to the N ATG base station cells respectively includes:

[0038] Generate N maximum gain antenna weights for aligning the airborne antenna direction with the N ATG base station cells according to the current maximum airborne antenna gain of the ATG airborne terminal to the N ATG base station cells;

[0039] The configured measurement gap is obtained, and during the measurement gap period, the actual values ​​of the current received signal strengths of the airborne terminal to the N ATG base station cells are measured using the N maximum gain antenna weights respectively.

[0040] In one implementation, selecting a new access cell for the ATG airborne terminal according to the actual value of the current received signal strength includes:

[0041] For the M (M≤N) ATG base station cells whose current actual received signal strength values ​​are greater than the preset threshold, a second sorting is performed in descending order according to the current actual received signal strength values, and the ATG airborne terminal is connected to the ATG base station cells in the order of the second sorting using the corresponding maximum gain antenna weights until access is successful.

[0042] In a second aspect, the present invention provides a ground-to-air communication ATG cell selection device,

[0043] The device comprises:

[0044] An acquisition module is used to acquire the X ATG base station cells that are currently closest to the ATG airborne terminal;

[0045] An estimation module, connected to the acquisition module, for calculating the estimated value of the current received signal strength of the ATG airborne terminal for the X ATG base station cells according to the current maximum airborne antenna gain of the ATG airborne terminal for the X ATG base station cells;

[0046] A selection module, connected to the estimation module, for selecting N ATG base station cells with the largest estimated values ​​of current received signal strength;

[0047] A measuring module, connected to the selection module, for measuring actual values ​​of current received signal strengths of the ATG airborne terminal to the N ATG base station cells according to current maximum airborne antenna gains of the ATG airborne terminal to the N ATG base station cells;

[0048] The selection module is connected to the measurement module and is also used to select a new access cell for the ATG airborne terminal according to the actual value of the current received signal strength.

[0049] In a third aspect, the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the ground-to-air communication ATG cell selection method as described above is implemented.

[0050] The present invention provides an ATG cell selection method, an ATG cell selection device and a computer-readable storage medium. In the process of selecting an ATG base station cell for an ATG airborne terminal, in order to avoid interference problems caused by omnidirectional measurement, the cell measurement is completed according to the current maximum airborne antenna gain of the ATG airborne terminal for each ATG base station cell to be measured, thereby suppressing co-channel interference in other directions and improving the link quality of communication. In order to narrow the measurement range and improve the measurement efficiency, the TopN ATG base station cells obtained by estimation are selected as measurement objects, thereby achieving the effect of efficiently completing the cell measurement and performing cell selection under the premise of suppressing interference. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 is a flow chart of an ATG cell selection method according to an embodiment of the present invention;

[0052] Figure 2 is a schematic diagram of a scenario of ATG system communication in an embodiment of the present invention;

[0053] Figure 3 is a flow chart of another ATG cell selection method according to an embodiment of the present invention;

[0054] Figure 4 It is a structural schematic diagram of an ATG cell selection device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0055] In order to enable those skilled in the art to better understand the technical solution of the present invention, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0056] It should be understood that the specific embodiments and drawings described herein are only used to explain the present invention rather than to limit the present invention.

[0057] It can be understood that, in the absence of conflict, the various embodiments of the present invention and the various features in the embodiments can be combined with each other.

[0058] It can be understood that, for the convenience of description, the drawings of the present invention only show the parts related to the present invention, while the parts irrelevant to the present invention are not shown in the drawings.

[0059] It can be understood that each unit and module involved in the embodiments of the present invention may correspond to only one physical structure, or may be composed of multiple physical structures, or multiple units and modules may be integrated into one physical structure.

[0060] It can be understood that, without conflict, the functions and steps marked in the flowcharts and block diagrams of the present invention may occur in an order different from that marked in the drawings.

[0061] It is understood that the flowcharts and block diagrams of the present invention illustrate the possible architectures, functions, and operations of the systems, devices, equipment, and methods according to the various embodiments of the present invention. Each box in the flowchart or block diagram may represent a unit, module, program segment, or code, which contains executable instructions for implementing the specified functions. Moreover, each box or combination of boxes in the block diagram and flowchart may be implemented by a hardware-based system that implements the specified functions, or by a combination of hardware and computer instructions.

[0062] It can be understood that the units and modules involved in the embodiments of the present invention can be implemented by software or hardware. For example, the units and modules can be located in a processor.

[0063] Embodiment 1:

[0064] like Figure 1 As shown, the present invention provides a method for selecting an ATG cell for ground-to-air communication, the method comprising:

[0065] S11, obtaining X ATG base station cells that are currently closest to the ATG airborne terminal;

[0066] S12, calculating the estimated value of the current received signal strength of the ATG airborne terminal for the X ATG base station cells according to the current maximum airborne antenna gain of the ATG airborne terminal for the X ATG base station cells;

[0067] S13, selecting N ATG base station cells with the largest estimated values ​​of current received signal strength;

[0068] S14, measuring actual values ​​of current received signal strengths of the ATG airborne terminal to the N ATG base station cells according to current maximum airborne antenna gains of the ATG airborne terminal to the N ATG base station cells;

[0069] S15. Select a new access cell for the ATG airborne terminal according to the actual value of the current received signal strength.

[0070] Specifically, since the frequency used by the ATG system is the same as that of the large ground network, if interference suppression measures are not adopted, serious mutual interference will occur between the two networks, affecting network performance. Therefore, it is necessary to always keep the narrow beam pointing to the location of the ATG base station cell, and use the narrow beam sidelobe to suppress interference in other directions. When the airborne terminal selects a cell (including access or switching a cell), it is necessary to evaluate the surrounding cells. The traditional method requires omnidirectional measurement. In this embodiment, multiple cells are first estimated according to the location information, sorted according to the theoretical estimate, and the cell with good signal coverage is selected, that is, the TopN cells with the highest RSRP (Reference Signal Receiving Power) expected to be received are obtained by calculation, and then the signal strength of the TopN cells is measured while keeping the narrow beam pointing to the cell, and the optimal access or switching target cell is selected according to the signal strength. The auxiliary means proposed reduces the number of cells to be measured, so that the optimal result can be obtained without omnidirectional measurement, ensuring that the narrow beam is suppressed while the interference is suppressed in a high interference background environment.

[0071] In one implementation, calculating the estimated value of the current received signal strength of the ATG airborne terminal for the X ATG base station cells according to the current maximum airborne antenna gain of the ATG airborne terminal for the X ATG base station cells respectively includes:

[0072] According to formula (1), the estimated value Pr of the current received signal strength of the ATG airborne terminal to X ATG base station cells is calculated respectively: i :

[0073] Pr i =Pt i +Gt i +Gr i -PL i

[0074] Among them, Pt i is the transmission power of the i-th ATG base station cell; Gt i Gr is the current cell antenna gain of the i-th ATG base station cell to the ATG airborne terminal; i is the current maximum airborne antenna gain of the ATG airborne terminal to the i-th ATG base station cell; PL i is the path loss of the ATG airborne terminal to the i-th ATG base station cell.

[0075] Specifically, in this embodiment, the estimation of the link received signal strength needs to consider the power (Pt) of the transmitter, the antenna gain (Gt) of the transmitter, the antenna gain (Gr) of the receiver, and the path loss (PL) in the middle. Since it is necessary to always maintain the shaping state so that the main lobe points to the ATG service cell and use the side lobe to suppress interference in other directions, the current received signal strength in the antenna shaping state in which the narrow beam is kept pointing to the location of the ATG base station cell is estimated to obtain the received signal (Pr i ) The strongest N cells are used as access cells or switching candidate target cells.

[0076] In one implementation, obtaining the X ATG base station cells that are currently closest to the ATG airborne terminal includes:

[0077] Obtain the current flight position of the ATG airborne terminal and the base station position of the ground ATG base station;

[0078] Obtaining several ground ATG base stations located within a preset distance range of the current flight position;

[0079] Obtaining cell antenna directions of X ATG base station cells and X ATG base station cells of the plurality of ground ATG base stations 2;

[0080] Obtain the airborne antenna gain table of the ATG airborne terminal, the cell transmission power and cell antenna gain table of each of the X ATG base station cells, and the ATG operating frequency.

[0081] Specifically, in this embodiment, if Figure 2 As shown, the ATG airborne terminal is located in the aircraft 1, and the ATG base station cell is the cell of the ground ATG base station 2. The number of ATG base station cells is related to the route. The northwest route is basically a linear coverage of 2 cells corresponding to each base station, and the southeast route is a common clover-shaped coverage of 3 cells corresponding to each base station. Using the known flight position, flight attitude, and the location information of the ground ATG base station 2, the following is calculated: Figure 2The four candidate ground ATG base stations 2 within the dotted line range shown are used to obtain the X cells closest to the aircraft 1 based on the four candidate ground ATG base stations 2. For example, the number of all cells within 100 kilometers around the real-time position of the aircraft (aircraft 1) is determined based on the distance. Because it will be estimated later, X can be more, and then the cell to be actually measured is determined by N. Because it is necessary to combine the aircraft's attitude information, the direction of the aircraft and the ground ATG base station 2, the directional diagram of the airborne terminal and the ground cell antenna, and calculate the signal strength value received by the onboard terminal, when the aircraft and the ground ATG base station 2 are in different relative positions, Gt and Gr have different values, so it is also necessary to obtain Pt, Gt, Gr related information and cell antenna direction, ATG operating frequency and other information.

[0082] In one embodiment, the method is performed by an ATG onboard terminal;

[0083] The current flight position is obtained in real time through the bus protocol connected to the aircraft 1;

[0084] The base station location, cell antenna direction, airborne antenna gain table, cell transmission power, cell antenna gain table, and ATG operating frequency are all pre-stored in the airborne terminal.

[0085] Specifically, in this embodiment, the ATG airborne terminal is connected to the aircraft 1 through the ARINC 429 (a bus protocol) bus to obtain the real-time latitude and longitude information, flight attitude information and other real-time aircraft positions. The information of the ground ATG base station 2 is pre-stored in the airborne terminal. The information pre-stored in the airborne terminal also includes a value table of Gt and Gr in different directions, including its own antenna gain value at different angles. The ground ATG base station 2 is a customized base station dedicated to ATG. About 500 base stations can achieve national route coverage. Therefore, the information of about 500 ground ATG base stations can be stored in the airborne terminal. Pt and Gt are base station information, and Gr is the airborne terminal information of this aircraft. They are all data pre-existing in the airborne terminal. This information is maintained in a unified ground data center and can be pushed to the terminal for update before takeoff.

[0086] In one embodiment, the current received signal strength estimation value Pr of the ATG airborne terminal to X ATG base station cells is calculated according to formula (1): i Previously, the method also included:

[0087] According to the current flight position, the base station position and the cell antenna direction, the first angle between the cell antenna direction of the i-th ATG base station cell and the ATG airborne terminal is obtained, and the cell antenna gain table of the i-th ATG base station cell is queried according to the first angle to obtain Gt i ;

[0088] Obtain the second angle at which the airborne antenna of the ATG airborne terminal is aligned with the i-th ATG base station cell according to the current flight position and the base station position, and query the airborne antenna gain table according to the second angle to obtain Gr i ;

[0089] Calculate the path loss PL of the ATG airborne terminal to the i-th ATG base station cell according to Equation (2) i :

[0090] PL i = 32.4 + 20 * logD i + 20 * logF i

[0091] where D i is the physical distance between the ATG airborne terminal and the ground ATG base station where the i-th ATG base station cell is located, calculated according to the current flight position and the base station position; F i is the ATG operating frequency.

[0092] Specifically, in this embodiment, before calculating the received signal strength of the X cells received when roughly calculating the position and attitude of the terminal, first calculate the path loss from the terminal antenna to the target cell antenna in real time. In the ground-air communication scenario, the path loss is usually calculated using the free space propagation model, relying on two variables, distance D and frequency F. According to Figure 2 shown, since the height in the longitude, latitude and attitude information is known, Figure 2 the horizontal distance r i between the aircraft 1 and a certain ground ATG base station 2 i and the height difference h i between the aircraft 1 and a certain ground ATG base station 2 are known, so that the physical distance D i between the two can be calculated, and F is the operating frequency of the ATG transmitting / receiving signal.

[0093] In one embodiment, select the N ATG base station cells with the largest current received signal strength estimation values, including:

[0094] Perform a first sorting on the X ATG base station cells according to the order of the current received signal strength estimation values from large to small, and select the first N ATG base station cells after the first sorting, where N is a value preset between 3 and 6.

[0095] Specifically, in this embodiment, sort and select the TopN ATG base station cells according to the current received signal strength estimation value for measurement. Generally, 3 < N < 6. If N is too small, it may be impossible to find a suitable cell, and if N is too large, it will waste resources.

[0096] In one implementation, measuring the actual value of the current received signal strength of the ATG airborne terminal to the N ATG base station cells according to the current maximum airborne antenna gain of the ATG airborne terminal to the N ATG base station cells respectively includes:

[0097] Generate N maximum gain antenna weights for aligning the airborne antenna direction with the N ATG base station cells according to the current maximum airborne antenna gain of the ATG airborne terminal to the N ATG base station cells;

[0098] The configured measurement gap is obtained, and during the measurement gap period, the actual values ​​of the current received signal strengths of the airborne terminal to the N ATG base station cells are measured using the N maximum gain antenna weights respectively.

[0099] Specifically, in this embodiment, according to the relative positions of the TopN cells and the airborne terminal, the shaping weights of the airborne antenna are changed, that is, the airborne antenna pattern is changed, so that the airborne antenna is pointed to the TopN cells for testing and verification, and the optimal result is obtained. First, according to the direction angle obtained by theoretical calculation, the airborne terminal antenna weights are calculated and generated according to the direction angle, that is, the maximum receiving gain is aligned with the direction of the selected cell antenna. There are N cells that need to be measured separately. The direction angle refers to the angle between the line connecting the airborne terminal and the ATG base station under test and the normal direction of the airborne antenna. The airborne terminal antenna weights refer to a set of antenna array element weights determined when the main lobe angle is known. The ATG antenna is an array composed of multiple elements. The generated weights are the amplitude and phase of each element. Through the coupling of all elements in the entire array, a specific antenna pattern is formed. Then, configure the measurement gap, and use the generated antenna weights to measure the actual signal strength of different target cells during the measurement gap period. The measurement gap can usually be configured as a measurement period and a measurement duration. The period is usually 20 to 160 ms, and the duration is usually 2 to 6 ms. Since the service being carried needs to be suspended (paused) when the measurement is started, a configuration that is too long affects performance, and a configuration that is too short affects timeliness. Configure multiple measurement gaps, and each gap is used to measure one cell.

[0100] In one implementation, selecting a new access cell for the ATG airborne terminal according to the actual value of the current received signal strength includes:

[0101] For the M (M≤N) ATG base station cells whose current actual received signal strength values ​​are greater than the preset threshold, a second sorting is performed in descending order according to the current actual received signal strength values, and the ATG airborne terminal is connected to the ATG base station cells in the order of the second sorting using the corresponding maximum gain antenna weights until access is successful.

[0102] Specifically, in this embodiment, calculation and measurement are performed on multiple cells separately. The measurement range is first narrowed by calculation, and then the cell with the best signal strength is selected according to the measurement results. The reason for not directly selecting the cell with the best calculated or measured signal strength is to prevent access failure caused by base station failure. Other cells can be used as alternatives. For example, the measurement results are sorted, and the cell corresponding to the maximum value of the measured received signal is the target cell. The airborne terminal uses the antenna weight pointing to the cell to access the cell. If the access fails, the second strongest signal cell can be used for access until it succeeds.

[0103] A more specific example of the above method is as follows Figure 3 As shown, including:

[0104] Step S101, start measurement, including two scenarios: access and cell switching. When a new cell is accessed, measurement is directly started. When an existing cell needs to be switched, whether to start measurement can be determined by the received signal strength. For example, -85dBm is configured. When the signal strength of the accessed cell is lower than the configured value, measurement of the neighboring cell is started;

[0105] Step S102: Obtain X cells. According to the real-time position information of the aircraft and the fixed position information of the ground ATG base station, obtain the X ATG base station cells closest to the aircraft as target cells.

[0106] Step S103, estimate X cells, combine the real-time position information of the aircraft (that is, the real-time position information of the airborne terminal), the position information of the ground ATG base station (that is, the cell position information), the direction of the airborne antenna (adjustable), and the direction of the cell antenna, and estimate the maximum received signal strength of the airborne terminal for each cell;

[0107] Step S104: Select the TopN cells, and select the best TopN cells according to the estimated maximum received signal strength. Under the condition that the airborne terminal always maintains narrow beamforming, the aircraft position and attitude parameters are used to assist in calculation, and the TopN cells with the largest estimated value of the current received signal strength are obtained as candidate cells, thereby narrowing the measurement range and improving the measurement efficiency.

[0108] Step S105, generating an airborne antenna pattern, generating an airborne antenna pattern that aligns the maximum receiving antenna gain with the TopN cells respectively;

[0109] Step S106: measure the TopN cells, use each generated airborne antenna pattern to measure the actual signal strength of the TopN cells respectively, use the configured measurement gap and the antenna weights generated based on the location information to measure the signal strength of the candidate cells, use the weights to participate in signal reception, suppress the same-frequency interference in other directions, improve the link quality of communication with the target cell, and obtain the optimal access cell;

[0110] Step S107, access a cell, starting from the cell with the strongest actual signal strength, until a cell is successfully accessed. If the access fails, that is, none of the selected cells are successfully accessed, recalculate the target cell and perform measurement access.

[0111] Embodiment 2:

[0112] like Figure 4 As shown, the present invention provides a ground-to-air communication ATG cell selection device, the device comprising:

[0113] An acquisition module 11 is used to acquire X ATG base station cells that are currently closest to the ATG airborne terminal;

[0114] The estimation module 12 is connected to the acquisition module 11 and is used to calculate the estimated value of the current received signal strength of the ATG airborne terminal for the X ATG base station cells according to the current maximum airborne antenna gain of the ATG airborne terminal for the X ATG base station cells;

[0115] The selection module 13 is connected to the estimation module 12 and is used to select N ATG base station cells with the largest estimated values ​​of the current received signal strength;

[0116] The measuring module 14 is connected to the selecting module 13 and is used to measure the actual value of the current received signal strength of the ATG airborne terminal to the N ATG base station cells according to the current maximum airborne antenna gain of the ATG airborne terminal to the N ATG base station cells;

[0117] The selection module 13 is connected to the measurement module 14 and is also used to select a new access cell for the ATG airborne terminal according to the actual value of the current received signal strength.

[0118] In one embodiment, the estimation module 12 includes:

[0119] The first calculation unit is used to calculate the current received signal strength estimation value Pr of the ATG airborne terminal to X ATG base station cells according to formula (1) respectively. i :

[0120] Pr i =Pt i +Gt i +Gr i -PL i

[0121] Among them, Pt i is the transmission power of the i-th ATG base station cell; Gt i Gr is the current cell antenna gain of the i-th ATG base station cell to the ATG airborne terminal; iis the current maximum airborne antenna gain of the ATG airborne terminal to the i-th ATG base station cell; PL i is the path loss of the ATG airborne terminal to the i-th ATG base station cell.

[0122] In one embodiment, the acquisition module 11 includes:

[0123] A first acquisition unit is used to acquire the current flight position of the ATG airborne terminal and the base station position of the ground ATG base station;

[0124] A second acquisition unit is used to acquire a plurality of ground ATG base stations whose base station positions are within a preset distance range of the current flight position;

[0125] A third acquisition unit is used to acquire the cell antenna directions of the X ATG base station cells and the X ATG base station cells of the plurality of ground ATG base stations;

[0126] The fourth acquisition unit is used to acquire the airborne antenna gain table of the ATG airborne terminal, the cell transmission power and cell antenna gain table of each of the X ATG base station cells, and the ATG operating frequency.

[0127] In one embodiment, the method is performed by an ATG onboard terminal;

[0128] The current flight position is obtained in real time through the bus protocol connected to the aircraft;

[0129] The base station location, cell antenna direction, airborne antenna gain table, cell transmission power, cell antenna gain table, and ATG operating frequency are all pre-stored in the airborne terminal.

[0130] In one embodiment, the estimation module 12 further includes a second calculation unit, which is used to:

[0131] According to the current flight position, the base station position and the cell antenna direction, the first angle between the cell antenna direction of the i-th ATG base station cell and the ATG airborne terminal is obtained, and the cell antenna gain table of the i-th ATG base station cell is queried according to the first angle to obtain Gt i ;

[0132] According to the current flight position and the base station position, the second angle of the airborne antenna direction of the ATG airborne terminal pointing to the i-th ATG base station cell is obtained, and the airborne antenna gain table is queried according to the second angle to obtain Gr i ;

[0133] According to formula (2), the path loss PL of the ATG airborne terminal to the i-th ATG base station cell is calculated: i :

[0134] PLi =32.4+20*logD i +20*logF i

[0135] Among them, D i is the physical distance between the ATG airborne terminal and the ground ATG base station where the i-th ATG base station cell is located, calculated based on the current flight position and base station position; F i is the ATG operating frequency.

[0136] In one embodiment, the selection module 13 includes:

[0137] The first selection unit is used to perform a first sorting on the X ATG base station cells according to the current received signal strength estimation value in descending order, and select the first N ATG base station cells after the first sorting, where N is a value preset between 3-6.

[0138] In one embodiment, the measuring module 14 includes:

[0139] A weighting unit, used to generate N maximum gain antenna weights for aligning the airborne antenna direction with the N ATG base station cells according to the current maximum airborne antenna gain of the ATG airborne terminal to the N ATG base station cells;

[0140] The measuring unit is used to obtain the configured measurement gap, and during the measurement gap period, respectively use N maximum gain antenna weights to measure the actual value of the current received signal strength of the airborne terminal to N ATG base station cells.

[0141] In one embodiment, the selection module 13 further includes:

[0142] The second selection unit is used to perform a second sorting on M (M≤N) ATG base station cells whose current actual received signal strength values ​​are greater than a preset threshold value in order from large to small according to the current actual received signal strength values, and use the corresponding maximum gain antenna weights to connect the ATG airborne terminal to the ATG base station cells in the order of the second sorting until access is successful.

[0143] Embodiment 3:

[0144] Embodiment 3 of the present invention provides a computer-readable storage medium, in which a computer program is stored. When the computer program is executed by a processor, the ground-to-air communication ATG cell selection method as described in Embodiment 1 is implemented.

[0145] The computer-readable storage medium includes volatile or non-volatile, removable or non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, computer program modules or other data). Computer-readable storage media include, but are not limited to, RAM (Random Access Memory), ROM (Read-Only Memory), EEPROM (Electrically Erasable Programmable read only memory), flash memory or other memory technology, CD-ROM (Compact Disc Read-Only Memory), digital versatile disk (DVD) or other optical disk storage, magnetic cassettes, magnetic tapes, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and can be accessed by a computer.

[0146] In addition, the present invention may also provide a computer device, including a memory and a processor, wherein the memory stores a computer program, and when the processor runs the computer program stored in the memory, the processor executes the ground-to-air communication ATG cell selection method as described in Example 1. The computer device may be the ground-to-air communication ATG cell selection device as described in Example 2.

[0147] The memory is connected to the processor, the memory may be a flash memory or a read-only memory or other memory, and the processor may be a central processing unit or a single-chip microcomputer.

[0148] Furthermore, the present invention can also provide a ground-to-air communication ATG system, including an ATG airborne terminal and a ground ATG base station, and the ATG airborne terminal executes the ground-to-air communication ATG cell selection method as described in Example 1 to enable itself to access a cell of a ground ATG base station.

[0149] Embodiments 1-3 of the present invention provide an ATG cell selection method, an ATG cell selection device, and a computer-readable storage medium. In the process of selecting an ATG base station cell for an ATG airborne terminal, in order to avoid interference problems caused by omnidirectional measurement, the cell measurement is completed according to the current maximum airborne antenna gain of the ATG airborne terminal for each ATG base station cell to be measured, thereby suppressing co-channel interference in other directions and improving the link quality of communication. In order to narrow the measurement range and improve the measurement efficiency, the TopN ATG base station cells obtained by estimation are selected as measurement objects, thereby achieving the effect of efficiently completing cell measurement and performing cell selection under the premise of suppressing co-channel interference.

[0150] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A method for selecting an ATG cell for ground-to-air communication, characterized in that: The method comprises: Obtain the X ATG base station cells that are currently closest to the ATG airborne terminal; Calculate the estimated values ​​of the current received signal strengths of the ATG airborne terminal for the X ATG base station cells according to the current maximum airborne antenna gains of the ATG airborne terminal for the X ATG base station cells; Select N ATG base station cells with the largest estimated received signal strength values; According to the current maximum airborne antenna gain of the ATG airborne terminal to the N ATG base station cells, the actual value of the current received signal strength of the ATG airborne terminal to the N ATG base station cells is measured; A new access cell for the ATG airborne terminal is selected according to the actual value of the current received signal strength.

2. The method according to claim 1, characterized in that According to the current maximum airborne antenna gain of the ATG airborne terminal for the X ATG base station cells, the estimated value of the current received signal strength of the ATG airborne terminal for the X ATG base station cells is calculated, including: According to formula (1), the estimated value Pr of the current received signal strength of the ATG airborne terminal to X ATG base station cells is calculated respectively: i : Pr i =Pt i +Gt i +Gr i -PL i Among them, Pt i is the transmission power of the i-th ATG base station cell; Gt i Gr is the current cell antenna gain of the i-th ATG base station cell to the ATG airborne terminal; i is the current maximum airborne antenna gain of the ATG airborne terminal to the i-th ATG base station cell; PL i is the path loss of the ATG airborne terminal to the i-th ATG base station cell.

3. The method according to claim 2, characterized in that Get the X ATG base station cells that are currently closest to the ATG airborne terminal, including: Obtain the current flight position of the ATG airborne terminal and the base station position of the ground ATG base station; Obtaining several ground ATG base stations located within a preset distance range of the current flight position; Obtaining cell antenna directions of X ATG base station cells and X ATG base station cells of the plurality of ground ATG base stations; Obtain the airborne antenna gain table of the ATG airborne terminal, the cell transmission power and cell antenna gain table of each of the X ATG base station cells, and the ATG operating frequency.

4. The method according to claim 3, characterized in that The method is performed by an ATG airborne terminal; The current flight position is obtained in real time through the bus protocol connected to the aircraft; The base station location, cell antenna direction, airborne antenna gain table, cell transmission power, cell antenna gain table, and ATG operating frequency are all pre-stored in the airborne terminal.

5. The method according to claim 3, characterized in that: According to formula (1), the estimated value Pr of the current received signal strength of the ATG airborne terminal to X ATG base station cells is calculated: i Previously, the method also included: According to the current flight position, the base station position and the cell antenna direction, the first angle between the cell antenna direction of the i-th ATG base station cell and the ATG airborne terminal is obtained, and the cell antenna gain table of the i-th ATG base station cell is queried according to the first angle to obtain Gt i ; According to the current flight position and the base station position, the second angle of the airborne antenna direction of the ATG airborne terminal aligning with the i-th ATG base station cell is obtained, and the airborne antenna gain table is queried according to the second angle to obtain Gr i ; According to formula (2), the path loss PL of the ATG airborne terminal to the i-th ATG base station cell is calculated: i : PL i =32.4+20*logD i +20*logF i Among them, D i is the physical distance between the ATG airborne terminal and the ground ATG base station where the i-th ATG base station cell is located, calculated based on the current flight position and base station position; F i is the ATG operating frequency.

6. The method according to any one of claims 1 to 5, characterized in that: Select N ATG base station cells with the largest estimated received signal strength values, including: The X ATG base station cells are first sorted in descending order according to the current received signal strength estimation values, and the first N ATG base station cells after the first sorting are selected, where N is a value preset between 3-6.

7. The method according to any one of claims 1 to 5, characterized in that: According to the current maximum airborne antenna gain of the ATG airborne terminal to the N ATG base station cells, the actual value of the current received signal strength of the ATG airborne terminal to the N ATG base station cells is measured, including: Generate N maximum gain antenna weights for aligning the airborne antenna direction with the N ATG base station cells according to the current maximum airborne antenna gain of the ATG airborne terminal to the N ATG base station cells; The configured measurement gap is obtained, and during the measurement gap period, the actual values ​​of the current received signal strengths of the airborne terminal to the N ATG base station cells are measured using the N maximum gain antenna weights respectively.

8. The method according to claim 7, characterized in that Selecting a new access cell for the ATG airborne terminal according to the actual value of the current received signal strength includes: For the M (M≤N) ATG base station cells whose current actual received signal strength values ​​are greater than the preset threshold, a second sorting is performed in descending order according to the current actual received signal strength values, and the ATG airborne terminal is connected to the ATG base station cells in the order of the second sorting using the corresponding maximum gain antenna weights until access is successful.

9. A ground-to-air communication ATG cell selection device, characterized in that: The device comprises: An acquisition module is used to acquire the X ATG base station cells that are currently closest to the ATG airborne terminal; An estimation module, connected to the acquisition module, for calculating the estimated value of the current received signal strength of the ATG airborne terminal for the X ATG base station cells according to the current maximum airborne antenna gain of the ATG airborne terminal for the X ATG base station cells; A selection module, connected to the estimation module, for selecting N ATG base station cells with the largest estimated values ​​of current received signal strength; A measuring module, connected to the selection module, for measuring actual values ​​of current received signal strengths of the ATG airborne terminal to the N ATG base station cells according to current maximum airborne antenna gains of the ATG airborne terminal to the N ATG base station cells; The selection module is connected to the measurement module and is also used to select a new access cell for the ATG airborne terminal according to the actual value of the current received signal strength.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the ground-to-air communication ATG cell selection method according to any one of claims 1 to 8 is implemented.

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