CN107231185B

CN107231185B - Machine-ground wireless communication device and method based on ADS-B signals

Info

Publication number: CN107231185B
Application number: CN201710419852.8A
Authority: CN
Inventors: 袁东明; 刘元安; 杨华明; 胡鹤飞; 冉静
Original assignee: Beijing University of Posts and Telecommunications; Boeing China Co Ltd
Current assignee: Beijing University of Posts and Telecommunications; Boeing China Co Ltd
Priority date: 2017-06-06
Filing date: 2017-06-06
Publication date: 2020-06-02
Anticipated expiration: 2037-06-06
Also published as: CN107231185A

Abstract

The invention discloses an air-ground wireless communication device and method based on ADS-B signals, and belongs to the field of wireless communication. The device comprises a receiving and decoding module, a control module and an antenna module; the control module is simultaneously connected with the receiving decoding module and the antenna module; the receiving and decoding module is used for receiving the ADS-B signal sent by the aircraft, decoding the ADS-B signal to acquire readable information and sending the readable information to the control module; the control module generates control information to control the plurality of antenna arrays of the antenna module and corresponding antennas in the antenna arrays; the frequency shift calculation unit calculates the frequency shift generated by the Doppler effect according to the position, the flight speed and the flight altitude of the aircraft and the emission wavelength of the antenna; the frequency compensation unit carries out timely compensation on the frequency of the antenna transmission signal according to the frequency movement; the invention changes the original signal coverage form of antenna parallel transmission into the signal coverage of space transmission from bottom to top; the antenna sector is smaller under the same signal coverage, thereby reducing the transmitting energy of the antenna.

Description

Machine-ground wireless communication device and method based on ADS-B signals

Technical Field

The invention relates to the field of wireless communication, in particular to an airport ground wireless communication device and method based on ADS-B signals.

Background

ADS-B (Automatic Dependent Surveillance-Broadcast), namely a Broadcast type Automatic correlation monitoring system, relies on accurate global satellite navigation positioning and all-weather operation to monitor (acquire) information such as the position, the altitude, the speed, the course, the identification number and the like of the airplane, and realizes mutual broadcasting of respective information data among the airplanes and between the airplane and the ground station. The method can automatically acquire parameters from relevant onboard equipment to broadcast the information of the airplane to other airplanes or ground stations without manual operation or inquiry, so that controllers can monitor the state of the airplane. In view of the advantages of ADS-B, the construction of ADS-B system is actively promoted worldwide.

An ADS-B equipped aircraft may broadcast its own precise location and other data (e.g., speed, altitude, whether the aircraft is turning, climbing or descending, etc.) over a data link. The ADS-B receiver can provide accurate and real-time conflict information in the air space by combining with an air traffic control system and the airborne ADS-B of other airplanes. This technology is widely used for communication, navigation and monitoring in today's air traffic control.

The ADS-B signal communication system used in the prior art has many problems, which are mainly reflected in: the more flight tracks, the more information elements and the shorter the repeated reporting period are agreed by the user and the operator, the higher the information service fee is paid, and the communication fee measured by telegraph in the SITA format is particularly expensive. On the other hand, on a low-density air route, air traffic service based on the monitoring technology of ADS-B and airline operation management can be realized, but high operation cost is prohibitive for users such as air traffic control and airlines. Therefore, advanced onboard equipment, built-in air-to-air data links, ground-to-air data links, and ground user equipment already deployed on an aircraft can only be a premium. On the other hand, on a high-density air route, the monitoring technology based on ADS-B is more difficult; and under the condition that a plurality of different wireless signals are covered in the same area, the mutual interference among the antennas is strong, and the service quality is seriously influenced.

In light of the above, there is a need for an ADS-B communication system with lower cost, higher capacity and lower interference to solve the above problems.

Disclosure of Invention

Aiming at the problems of high cost, low capacity, poor anti-interference capability and the like of the current airport ground wireless communication system, the invention provides an airport ground wireless communication device and method based on ADS-B signals in order to realize the positioning tracking of an aircraft and provide a convenient, flexible, low-energy-consumption and low-interference airport ground wireless communication service function;

the device comprises: the device comprises a receiving decoding module, a control module and an antenna module; the control module is simultaneously connected with the receiving decoding module and the antenna module;

the receiving and decoding module is used for receiving the ADS-B signal sent by the aircraft, decoding the ADS-B signal to acquire readable information of the aircraft and sending the readable information to the control module; the control module analyzes the readable information and generates control information for controlling the antenna module; the antenna module is provided with a plurality of antenna arrays, and the antenna arrays and corresponding antennas in the antenna arrays are intelligently switched according to the control information, so that wireless communication service of a plurality of antenna beams is provided for the aircraft.

The receiving decoding module includes: a receiving unit, an A/D converting unit and a decoding unit;

the receiving unit is provided with an external antenna and is used for receiving ADS-B analog signals sent by the aircraft and transmitting the ADS-B analog signals to the A/D conversion unit to be converted into 16-system digital signals; and the decoding unit analyzes the digital signal according to the message format of the ADS-B signal to acquire readable information of the aircraft.

The control module comprises an analysis unit, a frequency shift calculation unit, a frequency compensation unit and a priority processing unit;

the analysis unit generates control information according to readable information of the aircraft, wherein the control information comprises first antenna selection information and second antenna selection information;

the first antenna selection information selects one or more antenna arrays as specific antenna arrays according to the flight altitude and the latitude and longitude of the aircraft, and beams emitted by the specific antenna arrays respectively point to the positions of the aircraft. And the second antenna selection information selects to start the corresponding antenna in the specific antenna array according to the flight state of the aircraft.

The frequency shift calculation unit calculates the frequency shift generated by the Doppler effect according to the position, the flight speed and the flight altitude of the aircraft and the emission wavelength of the antenna;

the frequency compensation unit compensates the frequency of the signal transmitted by the antenna in time according to the frequency movement.

The priority processing unit performs grade division on all aircrafts according to all flight route information in the communication service range, and controls the antenna module to provide wireless communication services of different grades according to different grades of the aircrafts.

An airport wireless communication method based on ADS-B signals comprises the following steps:

step one, aiming at all aircrafts in a certain communication range, a receiving unit receives ADS-B analog signals sent by each aircraft and sends the received analog signals to an A/D conversion unit.

Step two, the A/D conversion unit converts the ADS-B analog signal into a 16-system digital signal and then sends the 16-system digital signal to the decoding unit.

And step three, the decoding unit analyzes the digital signal according to the message format of the ADS-B signal to obtain readable information of each aircraft.

The readable information includes: ICAO (international civil aviation organization), Flight number, Flight route, location, availability (Flight Altitude), Speed (Flight Speed), Longitude & Latitude (Latitude and Longitude), and the like.

Selecting one or more antenna arrays as specific antenna arrays from the antenna modules for each aircraft by the analysis unit according to the readable information of the aircraft, and starting corresponding antennas in the specific antenna arrays;

and starting corresponding antennas in the specific antenna array to enable the beams emitted by the specific antenna array to be focused and point to the position of the aircraft.

Fifthly, aiming at a certain selected antenna, the priority processing unit divides all aircrafts in the coverage area of the antenna into different grades;

the control module grades the communication service required by the flight according to the analyzed flight information of all the airplanes in the service range, and provides the preferential high-quality communication service for the airplane with high-quality service requirement.

And step six, the antenna module provides wireless communication service of the multi-beam antenna for the aircraft according to the sequence of the priority levels from high to low.

Step seven, the frequency shift calculation unit calculates the moving frequency f of each aircraft according to the selected antenna and by combining the position and the height of the aircraft_d；

The calculation is as follows:

v is the flight speed of the aircraft obtained by analyzing the ads-b signal, λ is the antenna emission wavelength in the specific antenna array, and cos θ is calculated from the position and altitude signals of the aircraft.

Step eight, moving f according to the frequency_dThe frequency compensation unit compensates the frequency of the transmission signal of the selected antenna in time.

The invention has the advantages that:

1) an antenna module comprising a plurality of antenna arrays is arranged, and the antenna arrays are intelligently switched, so that the original signal coverage form of antenna parallel transmission is changed into signal coverage of space transmission from bottom to top; the antenna sector is smaller under the same signal coverage, thereby reducing the transmitting energy of the antenna.

2) The antenna at the corresponding position is selected to be opened according to the position of the aircraft, the condition that the same area can be covered by various different wireless signals in the past is eliminated, the mutual interference among the antennas is reduced, and the service quality is improved.

Drawings

Fig. 1 is a schematic structural view of an airborne wireless communication apparatus based on ADS-B signals according to the present invention;

FIG. 2 is a schematic diagram of an aircraft-ground wireless communication device providing communication service to an aircraft based on ADS-B signals according to the present invention;

FIG. 3 is a schematic structural diagram of a receiving and decoding module in the ADS-B signal-based airborne wireless communication apparatus according to the present invention;

fig. 4 is a schematic diagram of readable information of an aircraft obtained by decoding the ADS-B signal in the embodiment of the present invention.

FIG. 5 is a schematic structural diagram of a control module in the ADS-B signal-based airborne wireless communication apparatus according to the present invention;

FIG. 6 is a schematic diagram of the ideal coverage area that multiple directional antennas can provide in the prior art;

FIG. 7 is a schematic diagram of the present invention in which the corresponding antenna beams are turned on by the aircraft position information;

FIG. 8 is a schematic diagram of the frequency shift resulting from the calculation of the Doppler effect of the present invention;

fig. 9 is a flow chart illustrating the method for wireless communication between an aircraft and a ground based on ADS-B signals according to the present invention.

DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION

The following describes in detail a specific embodiment of the present invention with reference to the drawings.

The invention relates to an airport ground wireless communication device based on ADS-B signals, which is used for realizing the positioning and tracking of an aircraft and providing wireless communication service; the method can be applied to the aspects of the current air traffic control, the wireless communication between the ground and the aircraft, the wireless network service for civil aircrafts in airports and the like.

Corresponding airborne equipment is installed on the airplane which communicates with the ground-to-aircraft wireless communication device and comprises an ATC (air traffic control) transponder, an MMR receiver, an ADIRU computer, a TCAS (traffic collision avoidance system) computer and a data link system. Wherein the content of the first and second substances,

(1) ATC (air traffic control) transponder: it is the core of ADS-B system, responsible for collecting and processing relevant parameters, broadcast by ATC antenna to ground station and other airplanes through data link.

(2) MMR receiver: used to calculate accurate aircraft position and velocity information from the navigation satellites for transmission to the ATC transponder.

(3) ADIRU computer: and providing the air data information such as the air pressure altitude of the airplane to the transponder.

(4) TCAS (collision avoidance system in air) computer: for an aircraft using the ADS-B IN function, the TCAS computer is used to receive the data chain of the 1090MHZ extension telegraph and display the signal from the ground station or other OUT IN the cockpit.

(5) Data chain system: both the OUT and IN functions of ADS-B are based on data link communication technology, and currently, the most widely used and recommended by the International civil aviation organization is 1090MHz frequency of the S-mode extended message (ES) function based on SSR. Since this band is the TCAS band, it is relatively crowded, and other data links including UAT and VDL Mode4 are being developed.

As shown in fig. 1, the machine-ground wireless communication device of the embodiment of the present invention specifically includes three modules: the antenna system comprises a receiving decoding module 11, a control module 12 and an antenna array module 13, wherein the control module 12 is simultaneously connected with the receiving decoding module 11 and the antenna array module 13;

the schematic diagram of the communication service provided by the ground-to-aircraft wireless communication device to the aircraft is shown in fig. 2, and the aircraft obtains flight-related parameters including 4-dimensional position information (longitude, latitude, altitude and time) of the aircraft and other possible additional information (collision warning information, pilot input information, track angle, flight inflection point and the like) as well as identification information and category information of the aircraft through a global satellite navigation system, an inertial reference system, a flight manager or other onboard sensors. In addition, other additional information such as heading, airspeed, wind speed, wind direction, aircraft outside temperature and the like may be included, the aircraft sends the parameters in the form of ADS-B signals, and the ground-to-aircraft wireless communication device based on the ADS-B signals receives the ADS-B signals sent by the aircraft (aircraft) by using the receiving and decoding module 11, decodes the ADS-B signals to obtain readable information of the aircraft, and sends the readable information to the control module 12;

the control module 12 analyzes the readable information and generates control information for controlling the antenna module 13;

the antenna module 13 is provided with a plurality of antenna arrays, and intelligently switches the antenna arrays and corresponding antennas in the antenna arrays according to the control information, so as to provide wireless communication services of a plurality of antenna beams for the aircraft.

Further, as shown in fig. 3, the receiving decoding module 11 includes: a receiving unit 31, an a/D converting unit 32, and a decoding unit 33;

the receiving unit 31 is generally a hardware device with an external antenna, and is configured to receive an ADS-B analog signal of 1090MHz sent by an aerial (or ground) aircraft, and send the received analog signal to the a/D converting unit 32.

The a/D conversion unit 32 converts the analog signal of ADS-B into a 16-ary digital signal, and then sends the obtained digital signal to the decoding unit 33.

The decoding unit 33 analyzes the 16-system digital signal according to the message format of the ADS-B signal to obtain readable information of the aircraft, and sends the readable information to the control module 12.

As shown in fig. 4, readable information for an aircraft includes, but is not limited to: ICAO (international civil aviation organization), Flight number, Flight route information, position information, availability (Flight height), Speed (Flight Speed), Longitude & Latitude (Latitude and Longitude), and the like. These readable information measured in the field may also include flight properties (international/national, model, number of passengers, quality of network demand, etc.).

As shown in fig. 5, the control module 12 includes an analyzing unit 51, a frequency shift calculating unit 52, a frequency compensating unit 53, and a priority processing unit 54;

the analysis unit 51 generates control information for controlling the antenna module 13 from the readable information of the aircraft;

the control information includes first antenna selection information and second antenna selection information;

the first antenna selection information selects one or more antenna arrays as a specific antenna array to provide wireless communication service for the aircraft according to the flight altitude and the latitude and longitude of the aircraft, so that beams emitted by the specific antenna array respectively point to the positions of the aircraft.

The analysis unit 51 calculates and evaluates each antenna array in the antenna module 13 according to the altitude, latitude and longitude information of the aircraft in the readable information, and selects to turn on a preferred antenna array, so that the beam emitted by the antenna array points to the aircraft position, thereby providing wireless communication service for the aircraft. Wherein, the preferred antenna array can be the closest to the airplane or the widest coverage range, etc.

And the second antenna selection information selects and starts the optimal corresponding antenna in the specific antenna array according to the flying state of the aircraft, so that the intelligent switching of the antenna is realized.

When the aircraft enters the coverage area of a group of preferred antenna arrays, the analysis unit 51 sequences the antennas in the preferred antenna arrays in real time according to the altitude and latitude and longitude information of the aircraft, and selects to turn on the antenna closest to the aircraft in real time to provide communication service for the aircraft, and simultaneously turns off other antennas in the preferred antenna arrays.

The frequency shift calculation unit 52 calculates the frequency shift generated by the doppler effect from the position, the flight speed, the flight altitude of the aircraft and the transmission wavelength of the antenna;

the frequency compensation unit 53 compensates the frequency of the antenna transmission signal in time according to the frequency shift.

The priority processing unit 54 performs ranking on all the aircraft according to all the flight route information within the communication service range, and controls the antenna module 13 to provide wireless communication services of different levels according to different ranks of the aircraft.

The wireless communication services of different levels comprise communication priorities and provide services for the priority of the wireless communication services requiring high priority; the signal quality of the communication network is prior, the requirement on the quality of the wireless communication network is high, and the wireless network service is provided preferentially.

The antenna module 13 is composed of a plurality of antenna arrays; as shown in fig. 6, the ideal coverage area provided by multiple directional antennas in the prior art is mostly achieved by multiple dual-beam antennas. Such a dual beam antenna may produce two mutually independent 38 degree beams separated by an angle of 60 degrees at their centers. Although this dual-lobe approach can provide an ideal coverage and only 3 antennas are needed to replace 6 independent single-beam antennas, it still has a great disadvantage compared with the present invention, specifically, the antenna sector is too large, which results in higher antenna transmission energy, and there may be many different wireless signal coverage conditions in the same area, which increases the mutual interference between antennas.

Compared with the signal coverage form of the conventional directional antenna in fig. 6, the multiple antenna arrays in the embodiment of the present invention change the original signal coverage form of antenna parallel transmission into signal coverage of bottom-to-top null transmission. Under the same signal coverage range, the antenna sector is smaller, so that the transmitting energy of the antenna is reduced; the antennas at corresponding positions are selected to be opened according to the positions of the airplanes, so that the condition that the same area can be covered by various different wireless signals in the past is eliminated, the mutual interference among the antennas is reduced, and the service quality is improved.

The antenna array turns on or off a part of antennas in the antenna array according to the control information sent by the control module 12, so that the whole antenna beam points to a specific position, and wireless communication service is provided for the airplane; as shown in fig. 7, when the aircraft flies from the rightmost side to the leftmost side, the antenna array sequentially and respectively opens 1-6 different signal coverage ranges according to the control information sent by the analysis unit 51, so that the whole antenna beam points to a specific position, thereby providing a wireless communication service for the aircraft.

An airport wireless communication method based on ADS-B signals, as shown in fig. 9, includes the following steps:

Selecting one or more antenna arrays from the antenna modules for the aircraft as specific antenna arrays according to the readable information of the aircraft by the analysis unit, and starting corresponding antennas in the specific antenna arrays;

the priority processing unit 54 performs level classification on all the airplanes according to the flight information of all the airplanes within the service range, and then controls the antenna module 13 to provide wireless communication services of different levels for the airplanes according to different levels of the airplanes.

The wireless communication services of different levels comprise communication priority and preferentially provide services for flights with high wireless communication service demand priority on one hand, and reasonable wireless networks are selected to provide wireless network services for the flights according to the requirements of the flights on the quality of wireless communication networks.

Specifically, in a place with many airplanes, such as an airport, on the one hand, all flight airplanes within the coverage area of the network service system are divided and clustered according to the acquired flight information (such as flight number) and the acquired flight properties (international and domestic, number of passengers on the flight), and the like. Carrying out priority ranking on the classified groups according to the level of A, B, C, D, and preferentially providing wireless network communication service for the groups with higher priority; on the other hand, all flight airplanes in the coverage range of the network service system are divided and clustered according to the acquired flight properties (high and low network required quality), the classified clusters are subjected to priority ranking according to the grades of 1, 2, 3 and 4, a reasonable wireless network is selected to provide wireless network service for the flight according to the quality requirement of the flight on the wireless communication network, the flight has the highest quality requirement on the wireless communication network, the optimal wireless network is provided for the service, and the high-efficiency service Quality (QOS) of the whole system is ensured.

Step seven, the frequency shift calculation unit calculates the moving frequency f of the aircraft according to the selected antenna and by combining the position and the height of the aircraft_d；

As shown in fig. 8, S is the location of the aircraft, and x is regarded as the antenna array location, the frequency shift formula is generated as follows:

f_dv is the flight speed of the aircraft obtained by analyzing the ads-b signal, and is directly read from readable information of the aircraft, and meanwhile, the position of the aircraft and the altitude information of the aircraft are extracted from the readable information; cos θ is calculated from the aircraft position and altitude signals. λ is the wavelength of the radio waves emitted by the antennas in a particular antenna array.

In controlling the antenna to transmit the radio wave, the frequency of the radio wave transmitted from the antenna is controlled to be timely compensated by the frequency compensation unit 53.

The invention realizes the tracking and positioning of the wireless network service system to the aircraft by utilizing the aircraft position information (GPS: longitude and latitude information) obtained by decoding of the ads-b module. And according to the position information (height, longitude and latitude) of the aircraft, the control system selects to turn on the corresponding sector antenna in the antenna system and points to the direction of the aircraft. Meanwhile, according to the flying state of the airplane, a proper wireless network hotspot is selected to provide network service for the airplane, and intelligent switching of the antenna in the system is realized. The Doppler frequency shift of the wireless signal can be estimated according to the acquired data such as the flight speed of the airplane, and the compensation is made on the transmitting power of the antenna. In places with many airplanes, such as airports, and the like, all flight airplanes in the coverage range of the network service system can be divided and clustered according to acquired flight information (flight numbers and the like) and flight properties (international and domestic, number of flight passengers, high and low network demand quality) and the like. Providing priority service with high requirement on the quality of service of the wireless network; and ensures the efficient quality of service (QoS) of the whole system.

Although the embodiments of the present invention have been described above, the above descriptions are only for the convenience of understanding the present invention, and are not intended to limit the present invention. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. An apparatus for wireless communications on an air-to-ground based on ADS-B signals, comprising: the device comprises a receiving decoding module, a control module and an antenna module; the control module is simultaneously connected with the receiving decoding module and the antenna module;

the receiving and decoding module is used for receiving the ADS-B signal sent by the aircraft, decoding the ADS-B signal to acquire readable information of the aircraft and sending the readable information to the control module; the control module analyzes the readable information and generates control information for controlling the antenna module; the antenna module is provided with a plurality of antenna arrays, and intelligently switches the antenna arrays and corresponding antennas in the antenna arrays according to the control information to provide wireless communication service of a plurality of antenna beams for the aircraft;

the first antenna selection information selects one or more antenna arrays as specific antenna arrays according to the flight altitude and the latitude and longitude of the aircraft, and beams emitted by the specific antenna arrays respectively point to the positions of the aircraft; the second antenna selection information selects to open a corresponding antenna in the specific antenna array according to the flight state of the aircraft;

the frequency compensation unit carries out timely compensation on the frequency of the antenna transmission signal according to the frequency movement;

2. An ADS-B signal based airborne wireless communication apparatus according to claim 1, wherein the receiving decoding module comprises a receiving unit, an A/D converting unit and a decoding unit;

3. An airborne wireless communication method of an airborne wireless communication apparatus based on ADS-B signals according to claim 1, comprising the steps of:

step one, aiming at all aircrafts in a certain communication range, a receiving unit receives ADS-B analog signals sent by each aircraft and sends the received analog signals to an A/D conversion unit;

step two, the A/D conversion unit converts the ADS-B analog signal into a 16-system digital signal and then sends the 16-system digital signal to the decoding unit;

step three, the decoding unit analyzes the digital signal according to the message format of the ADS-B signal to obtain readable information of each aircraft;

starting corresponding antennas in a specific antenna array to enable the beams emitted by the specific antenna array to be focused and point to the position of the aircraft;

the control module carries out grade division on communication services required by flights according to the analyzed flight information of all the airplanes in the service range, and provides priority high-quality communication services for airplanes with high-quality service requirements;

step six, the antenna module provides wireless communication service of the multi-beam antenna for the aircraft according to the sequence of the priority levels from high to low;

The calculation is as follows:

v is the flight speed of the aircraft obtained by analyzing the ads-b signal, lambda is the antenna emission wavelength in the specific antenna array, and cos theta is calculated by the position and altitude signals of the aircraft;

4. The method of claim 3, wherein the readable information includes: ICAO (international civil aviation organization), Flight number, Flight route, location, availability, Speed, and Longitude & Latitude.