CN110635831B - FDMA-based unmanned aerial vehicle measurement and control cellular communication method - Google Patents
FDMA-based unmanned aerial vehicle measurement and control cellular communication method Download PDFInfo
- Publication number
- CN110635831B CN110635831B CN201910943226.8A CN201910943226A CN110635831B CN 110635831 B CN110635831 B CN 110635831B CN 201910943226 A CN201910943226 A CN 201910943226A CN 110635831 B CN110635831 B CN 110635831B
- Authority
- CN
- China
- Prior art keywords
- unmanned aerial
- aerial vehicle
- base station
- frequency band
- frame
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
- H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
- H04B7/0413—MIMO systems
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/14—Relay systems
- H04B7/15—Active relay systems
- H04B7/185—Space-based or airborne stations; Stations for satellite systems
- H04B7/18502—Airborne stations
- H04B7/18506—Communications with or from aircraft, i.e. aeronautical mobile service
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/14—Relay systems
- H04B7/15—Active relay systems
- H04B7/185—Space-based or airborne stations; Stations for satellite systems
- H04B7/1851—Systems using a satellite or space-based relay
- H04B7/18517—Transmission equipment in earth stations
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/14—Relay systems
- H04B7/15—Active relay systems
- H04B7/185—Space-based or airborne stations; Stations for satellite systems
- H04B7/1853—Satellite systems for providing telephony service to a mobile station, i.e. mobile satellite service
- H04B7/18545—Arrangements for managing station mobility, i.e. for station registration or localisation
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/14—Relay systems
- H04B7/15—Active relay systems
- H04B7/185—Space-based or airborne stations; Stations for satellite systems
- H04B7/1853—Satellite systems for providing telephony service to a mobile station, i.e. mobile satellite service
- H04B7/18558—Arrangements for managing communications, i.e. for setting up, maintaining or releasing a call between stations
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W28/00—Network traffic management; Network resource management
- H04W28/02—Traffic management, e.g. flow control or congestion control
- H04W28/04—Error control
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W72/00—Local resource management
- H04W72/04—Wireless resource allocation
- H04W72/044—Wireless resource allocation based on the type of the allocated resource
- H04W72/0446—Resources in time domain, e.g. slots or frames
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W72/00—Local resource management
- H04W72/04—Wireless resource allocation
- H04W72/044—Wireless resource allocation based on the type of the allocated resource
- H04W72/0453—Resources in frequency domain, e.g. a carrier in FDMA
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W72/00—Local resource management
- H04W72/30—Resource management for broadcast services
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W72/00—Local resource management
- H04W72/50—Allocation or scheduling criteria for wireless resources
- H04W72/54—Allocation or scheduling criteria for wireless resources based on quality criteria
- H04W72/542—Allocation or scheduling criteria for wireless resources based on quality criteria using measured or perceived quality
Abstract
The invention discloses an unmanned aerial vehicle measurement and control cellular communication method based on FDMA, which comprises the following steps: building a hybrid base station; building a cellular communication network using the hybrid base station; allocating a downlink frequency band, an uplink frequency band and a broadband frequency band for the cellular communication network; allocating a narrow-band downlink frequency band and a narrow-band uplink frequency band for each unmanned aerial vehicle; selecting a movable base station of the unmanned aerial vehicle from the hybrid base station, and adjusting the direction of an antenna unit of the movable base station; the active base station sends notification information to the unmanned aerial vehicle, so that the direction of an antenna unit of the unmanned aerial vehicle is matched with the direction of a base station antenna unit of the active base station; the unmanned aerial vehicle broadcasts a telemetry frame signal in a narrow-band downlink frequency band; the active base station receives the telemetry frame signal, demodulates, decodes and analyzes the frame format to obtain a telemetry frame; the active base station forwards the telemetry frame to the master console; according to the invention, through the FDMA technology, signal interference among unmanned aerial vehicles is avoided, a plurality of unmanned aerial vehicles can be accommodated, and the problem of multiple access of an unmanned aerial vehicle measurement and control system is solved.
Description
Technical Field
The invention belongs to the technical field of unmanned aerial vehicle communication, and particularly relates to an unmanned aerial vehicle measurement and control cellular communication method based on FDMA.
Background
Along with the development of unmanned aerial vehicle technology, unmanned aerial vehicle no longer simply is applied to aspects such as movie & TV shooting, miniature autodyne, all has the application in fields such as agriculture, commodity circulation, disaster relief, observation wild animal, control infectious disease, survey and drawing, news report, electric power patrol inspection, and the measurement and control problem of medium and long distance unmanned aerial vehicle also gets more and more attentions. The unmanned aerial vehicle measurement and control system comprises unmanned aerial vehicle remote measurement, video downlink and unmanned aerial vehicle remote control. Unmanned aerial vehicle measurement and control are important means for tracking and positioning the unmanned aerial vehicle, monitoring the working state of the unmanned aerial vehicle, acquiring video data and remotely controlling the unmanned aerial vehicle. Through unmanned aerial vehicle telemetering measurement and video down, obtain unmanned aerial vehicle equipment state information, the sensor data that unmanned aerial vehicle carried on and the real-time video that unmanned aerial vehicle shot to through live broadcast video stream, afterwards analytical equipment state and sensor data, patrol and examine for unmanned aerial vehicle and provide indispensable effect with unmanned aerial vehicle's normal operating. Through unmanned aerial vehicle remote control, can control unmanned aerial vehicle and accomplish appointed action and task.
The existing unmanned aerial vehicle mostly adopts a radio station communication mode, the unmanned aerial vehicle is connected with a control console through a radio station, the communication distance of the unmanned aerial vehicle is limited, generally does not exceed 50 kilometers, and the unmanned aerial vehicle cannot meet medium and long distance measurement and control. A small part of remote flying unmanned aerial vehicles adopt satellite channels, and the unmanned aerial vehicles are required to carry satellite terminals, so that the cost is high; most satellite terminals are large in size and weight and need to occupy the limited load capacity of the unmanned aerial vehicle. Although the volume of a small number of satellite terminals is small, the code rate is low, and the requirement of image transmission cannot be met.
In addition, the existing unmanned aerial vehicle measurement and control systems mostly adopt point-to-point communication on a communication system, namely one measurement and control station only communicates with one unmanned aerial vehicle at the same time; although a small number of unmanned aerial vehicle measurement and control systems can accommodate a plurality of unmanned aerial vehicles, the number of the measurement and control ground stations is only one, and the measurement and control range of the supportable unmanned aerial vehicle is relatively small due to the small number of the measurement and control ground stations. At present, no unit or person adopts hybrid base station cellular communication for the unmanned aerial vehicle, and a corresponding mode for carrying out unmanned aerial vehicle physical layer communication based on FDMA (frequency division multiple access) and a corresponding self-defined link layer protocol do not appear.
Disclosure of Invention
In order to solve the problems in the prior art, the invention aims to provide an unmanned aerial vehicle measurement and control cellular communication method based on FDMA, which utilizes a cellular communication network to carry out communication, solves the problem that the measurement and control range of the unmanned aerial vehicle is too small in a radio station communication mode, and solves the problem that a satellite terminal is high in cost in a satellite communication mode.
The technical scheme adopted by the invention is as follows: an unmanned aerial vehicle measurement and control cellular communication method based on FDMA comprises the following steps:
building hybrid base stations, wherein each hybrid base station is provided with a base station antenna unit and a positioning module, and each unmanned aerial vehicle is provided with an unmanned aerial vehicle antenna unit and a positioning module;
building a cellular communication network using the hybrid base station;
allocating a downlink frequency band, an uplink frequency band and a broadband frequency band for the cellular communication network;
allocating a narrow-band downlink frequency band and a narrow-band uplink frequency band which are orthogonal to each other for each unmanned aerial vehicle, wherein the narrow-band downlink frequency band is in the range of the downlink frequency band, and the narrow-band uplink frequency band is in the range of the uplink frequency band;
each hybrid base station acquires the narrowband downlink carrier frequency and the narrowband uplink carrier frequency of each unmanned aerial vehicle, and stores the narrowband downlink carrier frequency and the narrowband uplink carrier frequency of each unmanned aerial vehicle in an unmanned aerial vehicle information table of the hybrid base station;
selecting a hybrid base station for dominating the unmanned aerial vehicle from the hybrid base stations as a movable base station of the unmanned aerial vehicle in each time slice delta t, and then adjusting the direction of an antenna unit of the movable base station per se;
the movable base station sends notification information to the unmanned aerial vehicles administered by the movable base station, so that each unmanned aerial vehicle adjusts the direction of the antenna unit of the unmanned aerial vehicle and is matched with the direction of the antenna unit of the base station of the movable base station administered by the unmanned aerial vehicle;
each unmanned aerial vehicle judges whether a movable base station governing the unmanned aerial vehicle exists or not, if so, the unmanned aerial vehicle transmits video stream data in a broadband frequency band by using an unmanned aerial vehicle antenna unit, codes and modulates a telemetry frame of the unmanned aerial vehicle, and up-converts the telemetry frame signal to a narrowband downlink frequency band broadcast telemetry frame signal of the unmanned aerial vehicle;
the active base station receives and demodulates the telemetry frame signals in the downlink frequency band, then selects demodulation channels of the unmanned aerial vehicle managed by the active base station from each channel of demodulation channels, and the active base station decodes the demodulation signals of the demodulation channels and analyzes the frame format to obtain the telemetry frame; the active base station receives video stream data of the unmanned aerial vehicle administered by the active base station at a broadband frequency band by using a base station antenna unit;
the active base station forwards the telemetering frame and video stream data of the unmanned aerial vehicle managed by the active base station to the master control station;
the main control console sends a remote control instruction frame to be executed by the unmanned aerial vehicle to a movable base station of the unmanned aerial vehicle to be remotely controlled;
the movable base station encodes, modulates and up-converts the remote control command frame to a narrow-band uplink frequency band broadcast remote control command frame signal of the unmanned aerial vehicle to be remotely controlled;
the method comprises the steps that a remote control command frame signal of a narrow-band uplink frequency band is received by a remote control unmanned aerial vehicle, and a remote control command frame is obtained after the remote control command frame signal is demodulated, decoded and analyzed in a frame format;
and the unmanned aerial vehicle to be remotely controlled executes the remote control instruction of the remote control instruction frame.
Preferably, in each time slice Δ t, selecting a hybrid base station for policing the drone from the hybrid base stations as an active base station of the drone, and then the active base station adjusting the direction of its own base station antenna unit includes the following steps:
in each time slice delta t, each unmanned aerial vehicle encodes, modulates and up-converts a downlink routing frame to a narrowband downlink frequency band of the unmanned aerial vehicle to broadcast a downlink routing frame signal, wherein the downlink routing frame comprises longitude Lng of the unmanned aerial vehiclevLatitude LatvHeight hvAnd a timestamp t;
each hybrid base station receives downlink routing frame signals in a downlink frequency band, processes the received downlink routing frame signals by adopting a parallel demodulation method, then respectively decodes the downlink routing frame signals of each demodulation channel and analyzes the frame format to obtain a downlink routing frame, and then stores the position information of the unmanned aerial vehicle in the downlink routing frame in an unmanned aerial vehicle position table of the hybrid base station;
each hybrid base station calculates the distance information between the hybrid base station and all unmanned aerial vehicles according to the position information of the unmanned aerial vehicles, and sends the distance information to a main control station, the main control station selects the hybrid base station with the closest distance for each unmanned aerial vehicle according to the distance information sent by each hybrid base station as the active base station of the unmanned aerial vehicle, and then the main control station writes the information of each active base station into an active base station information table of the main control station;
and each movable base station inquires the position information of the unmanned aerial vehicle governed by the movable base station from the unmanned aerial vehicle position table, and adjusts the direction of the antenna unit of the movable base station by combining the position information of the movable base station.
As a preferred mode, calculating the distance information between the unmanned aerial vehicle and the hybrid base station specifically includes: establishing a three-dimensional rectangular coordinate system by taking the geocentric as an origin, and then using the longitude Lng of the unmanned aerial vehiclevLatitude LatvHeight hvAnd longitude Lng of hybrid base stationBLatitude LatBAnd height hBRespectively converting the coordinates into coordinates under a three-dimensional rectangular coordinate system to obtain a coordinate point A (X) of the unmanned aerial vehiclev,Yv,Zv) And coordinate point B (X) of the hybrid base stationB,YB,ZB) Then, a coordinate point A (X) is calculatedv,Yv,Zv) And coordinate point B (X)B,YB,ZB) The distance between the unmanned aerial vehicle and the hybrid base station is the distance between the unmanned aerial vehicle and the hybrid base station
As a preferred mode, the method for enabling each unmanned aerial vehicle to adjust the direction of the antenna unit of the unmanned aerial vehicle and match the direction of the antenna unit of the base station governing the unmanned aerial vehicle comprises the following steps:
in each time slice delta t, the active base station encodes, modulates and up-converts an uplink routing frame to a narrowband uplink frequency band broadcast uplink routing frame signal of the unmanned aerial vehicle administered by the active base station, wherein the uplink routing frame comprises longitude Lng of the active base stationBLatitude LatBAnd height hB；
The unmanned aerial vehicle receives a remote control instruction frame signal of a narrow-band uplink frequency band, and demodulates, decodes and analyzes the remote control instruction frame signal to obtain an uplink routing frame;
and each unmanned aerial vehicle governs the direction of the antenna unit of the unmanned aerial vehicle according to the position information of the own movable base station governed by the uplink routing frame and combines the position information of the unmanned aerial vehicle to adjust the direction of the antenna unit of the unmanned aerial vehicle, so that the direction of the antenna unit of the unmanned aerial vehicle is matched with the direction of the antenna unit of the base station governing the own movable base station.
Preferably, the downlink routing frame, the uplink routing frame, the telemetry frame, and the remote control command frame are all provided with a checksum FCS field, and the checksum FCS field is used to determine whether a received frame is accurate.
Preferably, the base station antenna unit and the drone antenna unit both include an omni-directional antenna and a MIMO antenna.
Preferably, each drone transmits video stream data in a broadband frequency band using MIMO antennas.
As a preferred mode, the master console firstly queries the mobile base station of the unmanned aerial vehicle to be remotely controlled in the mobile base station information table, and then sends a remote control instruction frame to be executed by the unmanned aerial vehicle to the mobile base station of the unmanned aerial vehicle to be remotely controlled.
As a preferred mode, after the remote control unmanned aerial vehicle executes the remote control command, the unmanned aerial vehicle broadcasts the remote control command receipt in the narrowband downlink frequency band, and if the active base station does not successfully receive the remote control command receipt within the specified time, the active base station broadcasts the remote control command frame signal again.
The invention has the beneficial effects that:
1. according to the invention, through the hybrid base station cellular communication network, the problem that the measurement and control range of the unmanned aerial vehicle is too small in the radio station communication mode is solved, the problem that the cost of a satellite terminal is high in the satellite communication mode is solved, and the available load capacity of the unmanned aerial vehicle is relatively increased because the satellite terminal does not need to be carried.
2. According to the invention, different unmanned aerial vehicles are distinguished by utilizing mutually orthogonal frequency bands through an FDMA (frequency division multiple access) technology, so that interference between signals of each unmanned aerial vehicle is avoided, a system can accommodate a plurality of unmanned aerial vehicles, and the problem of multiple access of an unmanned aerial vehicle measurement and control system is solved.
3. The invention defines the unmanned aerial vehicle measurement and control link layer protocol, establishes unmanned aerial vehicle topology for the base station through the downlink routing frame, and selects a movable base station for each unmanned aerial vehicle; establishing an active base station topology for the unmanned aerial vehicle through the uplink routing frame; transmitting telemetry data for the unmanned aerial vehicle through the telemetry frame; sending a remote control instruction to the unmanned aerial vehicle through a remote control instruction frame; whether the unmanned aerial vehicle executes the command or not is judged through the remote control command receipt, the reliability of remote control command transmission is guaranteed, the remote control command receipt is relatively short, and the burden on the whole communication system is small.
4. The invention transmits the video downlink data of the unmanned aerial vehicle by using the directional antenna through the MIMO (multiple input multiple output) technology, allocates an independent frequency band for the video downlink, has good channel quality and large capacity, and meets the high bandwidth requirement of the video transmission of the unmanned aerial vehicle.
Drawings
FIG. 1 is a cellular communication topological diagram of a hybrid base station in an FDMA-based cellular communication method for unmanned aerial vehicle measurement and control;
fig. 2 is a working block diagram of a receiver of a hybrid base station in the FDMA-based unmanned aerial vehicle measurement and control cellular communication method provided by the invention;
fig. 3 is a flowchart of the work in the cellular communication method for unmanned aerial vehicle measurement and control based on FDMA provided by the invention.
Detailed Description
The embodiment provides an unmanned aerial vehicle measurement and control cellular communication method based on FDMA, which comprises the following steps of:
s1, building M mixed base stations BS0、BS1、BS2、…、BSM-1And each hybrid base station is provided with a base station antenna unit and a positioning module, each unmanned aerial vehicle is provided with an unmanned aerial vehicle antenna unit and a positioning module (GPS/Beidou/GALILEO/GLONASS), communication between the hybrid base station and the unmanned aerial vehicle is realized, and the hybrid base station and the main control console can communicate through any link, such as a relay satellite, a 3G/4G/5G network or an optical fiber, so that communication between the unmanned aerial vehicle and the main control console is solved. The base station antenna unit and the unmanned aerial vehicle antenna unit both comprise omnidirectional antennas and MIMO antennas, the omnidirectional antennas are used for transmitting telemetering and remote control data, and the MIMO antennas are used for transmitting video stream data. The invention transmits the video downlink data of the unmanned aerial vehicle by using the directional antenna through the MIMO (multiple input multiple output) technology, allocates an independent frequency band for the video downlink, has good channel quality and large capacity, and meets the high bandwidth requirement of the video transmission of the unmanned aerial vehicle.
S2, construction by using hybrid base stationA cellular communication network; as shown in fig. 1, a single hybrid base station in a cellular communication network can cover an area with a radius of 10-100 km, and a plurality of hybrid base stations can cover a larger area through reasonable layout, and in order to prevent some areas from being uncovered, coverage areas among the hybrid base stations are crossed. Longitude Lng of each hybrid base station once the cellular communication network is constructedBLatitude LatBAnd height hBIt can be written into the memory of the hybrid base station. The invention utilizes the hybrid base station cellular communication network, solves the problem that the measurement and control range of the unmanned aerial vehicle is too small in the radio station communication mode, solves the problem that the cost of the satellite terminal is high in the satellite communication mode, and relatively increases the available load capacity of the unmanned aerial vehicle because the satellite terminal is not required to be carried.
S3, allocating a downlink frequency band f for the cellular communication networkDL～fDUUplink frequency band fUL～fUUAnd a wideband frequency band. The downlink route and the remote measurement jointly use a downlink frequency band, the uplink route and the remote control jointly use an uplink frequency band, and the video downlink uses a broadband frequency band.
And S4, allocating a narrow-band downlink frequency band and a narrow-band uplink frequency band which are orthogonal to each other for each unmanned aerial vehicle, wherein the narrow-band downlink frequency band is in the range of the downlink frequency band, and the narrow-band uplink frequency band is in the range of the uplink frequency band. Assume a total of N drones V0、V1、V2、…、VN-1Then unmanned plane V0、V1、V2、…、VN-1The narrowband downlink carrier frequencies (i.e. the center frequencies of the narrowband downlink frequency bands) are respectively fD0、fD1、fD2、…、fDN-1The narrowband uplink carrier frequencies (i.e. the center frequencies of the narrowband uplink frequency bands) are respectively fU0、fU1、fU2、…、fUN-1(ii) a Wherein f isDL<fD0<fD1<fD2<…<fDN-1<fDU，fUL<fU0<fU1<fU2<…<fUN-1<fUUAnd the narrowband downlink frequency bands and the narrowband uplink frequency bands are mutually orthogonal to ensure that different unmanned aerial vehicle signals are not mutually interferedAnd (4) disturbing.
And S5, the master control station sends the narrowband downlink carrier frequency and the narrowband uplink carrier frequency of each unmanned aerial vehicle to each mixed base station, and each mixed base station stores the narrowband downlink carrier frequency and the narrowband uplink carrier frequency of each unmanned aerial vehicle into the unmanned aerial vehicle information table of the mixed base station after receiving the narrowband downlink carrier frequency and the narrowband uplink carrier frequency of each unmanned aerial vehicle. The format and description of the drone information table are shown in tables 101 and 102, respectively.
Table 101 format of drone information table
| Unmanned aerial vehicle numbering | Narrow band downlink carrier frequency | Narrow band uplink carrier frequency |
| UINT16 type, 2 bytes | FLOAT, 4 bytes | FLOAT, 4 bytes |
Table 102 description of drone information table
| Name (R) | Description of the invention |
| Unmanned aerial vehicle numbering | Assigning a unique number to a drone, UINT16 type, 2 bytes |
| Narrowband downlink frequency | The narrow-band downlink carrier frequency, FLOAT type, 4 bytes of the unmanned aerial vehicle |
| Narrow band uplink frequency | The narrow-band uplink carrier frequency, FLOAT type, 4 bytes of the unmanned aerial vehicle |
S6, in each time slice Δ t, selecting a hybrid base station used for policing the drone from the hybrid base stations as a moving base station of the drone, and then adjusting the direction of the antenna unit of the moving base station, specifically including the following steps:
s61, in each time slice delta t, each unmanned aerial vehicle acquires longitude Lng of the unmanned aerial vehicle from the positioning module (GPS/Beidou/GALILEO/GLONASS) in each time slice delta tvLatitude LatvHeight hvAnd a time stamp t and forms a downstream routing frame RDEach unmanned aerial vehicle encodes, modulates and up-converts the downlink routing frame to the narrowband downlink frequency band of the unmanned aerial vehicle to broadcast the downlink routing frame signal. Wherein, the downlink route frame RDThe format of (a) and its description are shown in tables 103 and 104, respectively.
Table 103 downstream routing frame format
Table 104 format description of downstream routing frame
S62, each mixed base station receives the downlink route frame signal in the downlink frequency band, and processes the received downlink route frame signal by adopting a parallel demodulation method, the receiver of each mixed base station has N paths of demodulation channels which respectively correspond to N unmanned aerial vehicles in total, and each path of demodulation channel adopts a narrow-band downlink frequency band corresponding to the unmanned aerial vehicleThe operation of the receiver of the hybrid base station for demodulation is shown in figure 2. Because the narrowband downlink frequency bands of each unmanned aerial vehicle are orthogonal, each branch only demodulates the downlink routing frame signal of the corresponding unmanned aerial vehicle. The hybrid base station respectively decodes the downlink routing frame signals of each demodulation channel and analyzes the frame format to obtain a downlink routing frame, judges whether the received downlink routing frame is accurate or not according to a check sum FCS field in the downlink routing frame, and discards the downlink routing frame if the received downlink routing frame is not accurate; if yes, the hybrid base station stores the position information of the unmanned aerial vehicle in the downlink routing frame in an unmanned aerial vehicle position table of the hybrid base station, and the position information of the unmanned aerial vehicle in the frame comprises longitude Lng of the unmanned aerial vehiclevLatitude LatvHeight hv. The format of the drone location table and its description are shown in tables 105 and 106, respectively.
Table 105 format of drone location table
Table 106 description of drone location table
| Name (R) | Description of the invention |
| Unmanned aerial vehicle numbering | Assigning a unique number to a drone, UINT16 type, 2 bytes |
| Longitude (G) | Abscissa of unmanned plane in earth spherical coordinate system, FLOAT type, 4 bytes |
| Latitude | Unmanned plane on earthOrdinate of the spherical coordinate System, FLOAT type, 4 bytes |
| Height | Altitude of unmanned aerial vehicle, FLOAT type, 4 bytes |
| Time stamp | Time information acquired by unmanned aerial vehicle to positioning module, DATETIME, 4 bytes |
And S63, each hybrid base station calculates the distance information between itself and all unmanned aerial vehicles according to the position information of the unmanned aerial vehicles, and sends the distance information to the master control station, the master control station selects the hybrid base station with the closest distance for each unmanned aerial vehicle according to the distance information sent by each hybrid base station as the active base station of the unmanned aerial vehicle, the master control station informs the hybrid base stations to become the active base stations of the corresponding unmanned aerial vehicles, then the master control station writes the information of each active base station into an active base station information table of the master control station, and the formats and descriptions of the active base station information tables are respectively shown in tables 107 and 108. Wherein, it specifically is to calculate the distance information between unmanned aerial vehicle and the hybrid base station: establishing a three-dimensional rectangular coordinate system by taking the geocentric as an origin, and then using the longitude Lng of the unmanned aerial vehiclevLatitude LatvHeight hvAnd longitude Lng of hybrid base stationBLatitude LatBAnd height hBRespectively converting the coordinates into coordinates under a three-dimensional rectangular coordinate system to obtain a coordinate point A (X) of the unmanned aerial vehiclev,Yv,Zv) And coordinate point B (X) of the hybrid base stationB,YB,ZB) Then, a coordinate point A (X) is calculatedv,Yv,Zv) And coordinate point B (X)B,YB,ZB) The distance between the unmanned aerial vehicle and the hybrid base station is the distance between the unmanned aerial vehicle and the hybrid base station
Table 107 active base station information table
| Unmanned aerial vehicle numbering | Active base station numbering |
| UINT16 type, 2 bytes | UINT16 type, 2 bytes |
Table 108 description of the active base station information table
| Name (R) | Description of the invention |
| Unmanned aerial vehicle numbering | Assigning a unique number to a drone, UINT16 type, 2 bytes |
| Active base station numbering | Hybrid base station number, UINT16, 2 bytes for the drone to transmit telemetry signals |
And S64, each movable base station inquires the position information of the unmanned aerial vehicle governed by the movable base station from the unmanned aerial vehicle position table, and adjusts the direction of the MIMO antenna beam of the movable base station by combining the position information of the movable base station so as to well receive video stream data.
S7, the mobile base station sends notification information to the unmanned aerial vehicles managed by the mobile base station, so that each unmanned aerial vehicle adjusts the direction of the antenna unit of the unmanned aerial vehicle and matches the direction of the antenna unit of the base station that manages the mobile base station, specifically including the following steps:
s71, the active base station sends its longitude Lng in each time slice Δ tBLatitude LatBAnd height hBEncapsulated as an upstream routing frame RUUpstream routing frame RUThe format of (a) and its description are shown in tables 109 and 110, respectively. And the active base station inquires the narrowband uplink frequency band of the unmanned aerial vehicle managed by the active base station from the unmanned aerial vehicle information table, encodes, modulates and up-converts the uplink routing frame to the narrowband uplink frequency band of the unmanned aerial vehicle managed by the active base station to broadcast the uplink routing frame signal.
Table 109 upstream routing frame format
Table 110 format description of upstream routing frame
And S72, receiving the remote control instruction frame signal of the narrow-band uplink frequency band by the unmanned aerial vehicle, and demodulating, decoding and analyzing the frame format of the remote control instruction frame signal to obtain an uplink routing frame. The unmanned aerial vehicle judges whether the received uplink routing frame is accurate or not through a check sum FCS field in the uplink routing frame, and if not, the uplink routing frame is discarded; if yes, the process proceeds to S73.
S73, each unmanned aerial vehicle governs the position information of the own movable base station according to the uplink routing frame, and the position information comprises longitude Lng of the movable base stationBLatitude LatBAnd height hBAnd the direction of the MIMO antenna beam of the unmanned aerial vehicle is adjusted by combining the position information of the unmanned aerial vehicle, so that the MIMO antenna direction of the unmanned aerial vehicle is matched with the MIMO antenna direction of the active base station which governs the unmanned aerial vehicle, and the active base station can be ensured to be capable of receiving video stream data well.
And S8, each unmanned aerial vehicle judges whether an active base station which governs the unmanned aerial vehicle exists, and if so, the unmanned aerial vehicle transmits video stream data in a broadband frequency band by using the MIMO antenna. The unmanned aerial vehicle encodes and modulates the telemetry frame of the unmanned aerial vehicle, and the telemetry frame signal is up-converted to a narrow-band downlink frequency band broadcast of the unmanned aerial vehicle. The unmanned aerial vehicle acquires telemetry data from the telemetry equipment and forms a telemetry frame F, acquires video data from the camera equipment and forms video stream data, if no telemetry data exists at some time, the telemetry frame is empty, and the format and description of the telemetry frame are respectively shown in table 111 and table 112.
Table 111 telemetry frame format
Table 112 telemetry frame format description
S9, the active base station receives and demodulates the telemetering frame signal in the downlink frequency band, then selects the demodulation channel of the unmanned aerial vehicle managed by the active base station from each channel of demodulation channel, and the active base station decodes the demodulation signal of the demodulation channel and analyzes the frame format to obtain the telemetering frame; because the narrowband downlink frequency bands adopted by each unmanned aerial vehicle are mutually orthogonal, each branch of the receiver of the active base station can only demodulate the telemetry frame signal corresponding to the unmanned aerial vehicle. The active base station judges whether the telemetering frame is accurate or not through a check sum FCS field in the telemetering frame; if not, the telemetry frame is discarded, and if so, the process proceeds to step S10. The active base station receives video stream data of the unmanned aerial vehicle administered by the active base station in a broadband frequency band by using the MIMO antenna.
And S10, the active base station forwards the telemetry frame and the video stream data of the unmanned aerial vehicle governed by the active base station to the master console.
The main control console sends a remote control instruction to the unmanned aerial vehicle, and the following steps are required.
And S11, the master console inquires the movable base station of the unmanned aerial vehicle to be remotely controlled in the movable base station information table, and the master console sends a remote control instruction frame to be executed by the unmanned aerial vehicle to the movable base station of the unmanned aerial vehicle to be remotely controlled. The format of the remote control instruction frame and its description are shown in tables 113 and 114, respectively.
Table 113 remote control instruction frame format
Table 114 format description of remote control instruction frame
And S12, the active base station inquires the narrowband uplink frequency band of the unmanned aerial vehicle to be remotely controlled from the unmanned aerial vehicle information table, and the active base station encodes, modulates and up-converts the remote control command frame to the narrowband uplink frequency band of the unmanned aerial vehicle to be remotely controlled to broadcast the remote control command frame signal.
S13, the unmanned aerial vehicle to be remotely controlled receives the remote control instruction frame signal of the narrow-band uplink frequency band, and the remote control instruction frame signal is demodulated, decoded and analyzed in frame format to obtain a remote control instruction frame; then the remote control unmanned aerial vehicle judges whether the remote control instruction frame is accurate or not through a check sum FCS field in the remote control instruction frame; if not, the remote control command frame is discarded, and if so, the process proceeds to step S14.
S14, the unmanned aerial vehicle to be remotely controlled executes the remote control command of the remote control command frame, then the unmanned aerial vehicle broadcasts the remote control command receipt in the narrow-band downlink frequency band, and if the active base station does not successfully receive the remote control command receipt within the specified time, the active base station rebroadcasts the remote control command frame signal. The format of the remote control command receipt and its description are shown in tables 115 and 116, respectively.
Form of table 115 remote control instruction receipt
Description of remote control command receipt for Table 116
After entering the next time slice Δ t, the steps S6 to S14 are repeated.
According to the invention, different unmanned aerial vehicles are distinguished by utilizing mutually orthogonal frequency bands through an FDMA (frequency division multiple access) technology, so that interference between signals of each unmanned aerial vehicle is avoided, a system can accommodate a plurality of unmanned aerial vehicles, and the problem of multiple access of an unmanned aerial vehicle measurement and control system is solved. The invention defines the unmanned aerial vehicle measurement and control link layer protocol, establishes unmanned aerial vehicle topology for the base station through the downlink routing frame, and selects a movable base station for each unmanned aerial vehicle; establishing an active base station topology for the unmanned aerial vehicle through the uplink routing frame; transmitting telemetry data for the unmanned aerial vehicle through the telemetry frame; sending a remote control instruction to the unmanned aerial vehicle through a remote control instruction frame; whether the unmanned aerial vehicle executes the command or not is judged through the remote control command receipt, the reliability of remote control command transmission is guaranteed, the remote control command receipt is relatively short, and the burden on the whole communication system is small.
The present invention is not limited to the above-described alternative embodiments, and various other forms of products can be obtained by anyone in light of the present invention. The above detailed description should not be taken as limiting the scope of the invention, which is defined in the claims, and which the description is intended to be interpreted accordingly.
Claims (9)
1. An unmanned aerial vehicle measurement and control cellular communication method based on FDMA is characterized by comprising the following steps:
building hybrid base stations, wherein each hybrid base station is provided with a base station antenna unit and a positioning module, and each unmanned aerial vehicle is provided with an unmanned aerial vehicle antenna unit and a positioning module;
building a cellular communication network using the hybrid base station;
allocating a downlink frequency band, an uplink frequency band and a broadband frequency band for the cellular communication network;
allocating a narrow-band downlink frequency band and a narrow-band uplink frequency band which are orthogonal to each other for each unmanned aerial vehicle, wherein the narrow-band downlink frequency band is in the range of the downlink frequency band, and the narrow-band uplink frequency band is in the range of the uplink frequency band;
each hybrid base station acquires the narrowband downlink carrier frequency and the narrowband uplink carrier frequency of each unmanned aerial vehicle, and stores the narrowband downlink carrier frequency and the narrowband uplink carrier frequency of each unmanned aerial vehicle in an unmanned aerial vehicle information table of the hybrid base station;
selecting a hybrid base station for dominating the unmanned aerial vehicle from the hybrid base stations as a movable base station of the unmanned aerial vehicle in each time slice delta t, and then adjusting the direction of an antenna unit of the movable base station per se;
the movable base station sends notification information to the unmanned aerial vehicles administered by the movable base station, so that each unmanned aerial vehicle adjusts the direction of the antenna unit of the unmanned aerial vehicle and is matched with the direction of the antenna unit of the base station of the movable base station administered by the unmanned aerial vehicle;
each unmanned aerial vehicle judges whether a movable base station governing the unmanned aerial vehicle exists or not, if so, the unmanned aerial vehicle transmits video stream data in a broadband frequency band by using an unmanned aerial vehicle antenna unit, codes and modulates a telemetry frame of the unmanned aerial vehicle, and up-converts the telemetry frame signal to a narrowband downlink frequency band broadcast telemetry frame signal of the unmanned aerial vehicle;
the active base station receives and demodulates the telemetry frame signals in the downlink frequency band, then selects demodulation channels of the unmanned aerial vehicle managed by the active base station from each channel of demodulation channels, and the active base station decodes the demodulation signals of the demodulation channels and analyzes the frame format to obtain the telemetry frame; the active base station receives video stream data of the unmanned aerial vehicle administered by the active base station at a broadband frequency band by using a base station antenna unit;
the active base station forwards the telemetering frame and video stream data of the unmanned aerial vehicle managed by the active base station to the master control station;
the main control console sends a remote control instruction frame to be executed by the unmanned aerial vehicle to a movable base station of the unmanned aerial vehicle to be remotely controlled;
the movable base station encodes, modulates and up-converts the remote control command frame to a narrow-band uplink frequency band broadcast remote control command frame signal of the unmanned aerial vehicle to be remotely controlled;
the method comprises the steps that a remote control command frame signal of a narrow-band uplink frequency band is received by a remote control unmanned aerial vehicle, and a remote control command frame is obtained after the remote control command frame signal is demodulated, decoded and analyzed in a frame format;
and the unmanned aerial vehicle to be remotely controlled executes the remote control instruction of the remote control instruction frame.
2. The FDMA-based unmanned aerial vehicle measurement and control cellular communication method of claim 1, wherein the step of selecting a hybrid base station for policing the unmanned aerial vehicle from the hybrid base stations as an active base station of the unmanned aerial vehicle in each time slice Δ t, and then the active base station adjusting the direction of an antenna unit of the base station comprises the steps of:
in each time slice delta t, each unmanned aerial vehicle encodes, modulates and up-converts a downlink routing frame to a narrowband downlink frequency band of the unmanned aerial vehicle to broadcast a downlink routing frame signal, wherein the downlink routing frame comprises longitude Lng of the unmanned aerial vehiclevLatitude LatvHeight hvAnd a timestamp t;
each hybrid base station receives downlink routing frame signals in a downlink frequency band, processes the received downlink routing frame signals by adopting a parallel demodulation method, then respectively decodes the downlink routing frame signals of each demodulation channel and analyzes the frame format to obtain a downlink routing frame, and then stores the position information of the unmanned aerial vehicle in the downlink routing frame in an unmanned aerial vehicle position table of the hybrid base station;
each hybrid base station calculates the distance information between the hybrid base station and all unmanned aerial vehicles according to the position information of the unmanned aerial vehicles, and sends the distance information to a main control station, the main control station selects the hybrid base station with the closest distance for each unmanned aerial vehicle according to the distance information sent by each hybrid base station as the active base station of the unmanned aerial vehicle, and then the main control station writes the information of each active base station into an active base station information table of the main control station;
and each movable base station inquires the position information of the unmanned aerial vehicle governed by the movable base station from the unmanned aerial vehicle position table, and adjusts the direction of the antenna unit of the movable base station by combining the position information of the movable base station.
3. The FDMA-based unmanned aerial vehicle measurement and control cellular communication method of claim 2, wherein the calculating of the distance information between the unmanned aerial vehicle and the hybrid base station specifically comprises: establishing a three-dimensional rectangular coordinate system by taking the geocentric as an origin, and then using the longitude Lng of the unmanned aerial vehiclevLatitude LatvHeight hvAnd longitude Lng of hybrid base stationBLatitude LatBAnd height hBRespectively converting the coordinates into coordinates under a three-dimensional rectangular coordinate system to obtain a coordinate point A (X) of the unmanned aerial vehiclev,Yv,Zv) And coordinate point B (X) of the hybrid base stationB,YB,ZB) Then, a coordinate point A (X) is calculatedv,Yv,Zv) And coordinate point B (X)B,YB,ZB) The distance between the unmanned aerial vehicle and the hybrid base station is the distance between the unmanned aerial vehicle and the hybrid base station
4. The FDMA-based unmanned aerial vehicle measurement and control cellular communication method of claim 2, wherein the active base station sends notification information to the unmanned aerial vehicle under jurisdiction so that each unmanned aerial vehicle adjusts the direction of the antenna unit of the unmanned aerial vehicle and matches the direction of the antenna unit of the base station of the active base station under jurisdiction, comprising the steps of:
in each time slice delta t, the active base station encodes, modulates and up-converts an uplink routing frame to a narrowband uplink frequency band broadcast uplink routing frame signal of the unmanned aerial vehicle administered by the active base station, wherein the uplink routing frame comprises longitude Lng of the active base stationBLatitude LatBAnd height hB；
The unmanned aerial vehicle receives a remote control instruction frame signal of a narrow-band uplink frequency band, and demodulates, decodes and analyzes the remote control instruction frame signal to obtain an uplink routing frame;
and each unmanned aerial vehicle governs the direction of the antenna unit of the unmanned aerial vehicle according to the position information of the own movable base station governed by the uplink routing frame and combines the position information of the unmanned aerial vehicle to adjust the direction of the antenna unit of the unmanned aerial vehicle, so that the direction of the antenna unit of the unmanned aerial vehicle is matched with the direction of the antenna unit of the base station governing the own movable base station.
5. The FDMA-based unmanned aerial vehicle measurement and control cellular communication method of claim 4, wherein the downlink routing frame, the uplink routing frame, the telemetry frame and the remote control command frame are all provided with a checksum FCS field, and the checksum FCS field is used for judging whether the received frames are accurate.
6. The FDMA-based unmanned aerial vehicle measurement and control cellular communication method of claim 1, wherein the base station antenna unit and the unmanned aerial vehicle antenna unit each comprise an omni-directional antenna and a MIMO antenna.
7. The FDMA-based drone measurement and control cellular communication method of claim 6, wherein each drone uses MIMO antennas to send video stream data in broadband bands.
8. The FDMA-based unmanned aerial vehicle measurement and control cellular communication method of claim 2, wherein the master station first queries an active base station of the unmanned aerial vehicle to be remotely controlled in an active base station information table, and then the master station sends a remote control instruction frame to be executed by the unmanned aerial vehicle to the active base station of the unmanned aerial vehicle to be remotely controlled.
9. The FDMA-based unmanned aerial vehicle measurement and control cellular communication method of claim 1, wherein after a remote control command is executed by a remote control unmanned aerial vehicle, the unmanned aerial vehicle broadcasts a remote control command receipt in a narrowband downlink frequency band, and if an active base station does not successfully receive the remote control command receipt within a specified time, the active base station rebroadcasts a remote control command frame signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910943226.8A CN110635831B (en) | 2019-09-30 | 2019-09-30 | FDMA-based unmanned aerial vehicle measurement and control cellular communication method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910943226.8A CN110635831B (en) | 2019-09-30 | 2019-09-30 | FDMA-based unmanned aerial vehicle measurement and control cellular communication method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110635831A CN110635831A (en) | 2019-12-31 |
| CN110635831B true CN110635831B (en) | 2020-08-14 |
Family
ID=68975623
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910943226.8A Active CN110635831B (en) | 2019-09-30 | 2019-09-30 | FDMA-based unmanned aerial vehicle measurement and control cellular communication method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110635831B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111901031A (en) * | 2020-07-31 | 2020-11-06 | 苏州巨跶航智能科技有限公司 | Vehicle-mounted unmanned aerial vehicle ad hoc network enhancement system |
| CN112614325B (en) * | 2020-12-07 | 2022-03-29 | 上海卫星工程研究所 | Separated microsatellite measurement and control system, method and medium |
| CN112737837B (en) * | 2020-12-28 | 2021-09-14 | 北京邮电大学 | Method for allocating bandwidth resources of unmanned aerial vehicle cluster under high dynamic network topology |
| WO2022252066A1 (en) * | 2021-05-31 | 2022-12-08 | 深圳市大疆创新科技有限公司 | Antenna selection method of mobile platform and mobile platform |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108808243A (en) * | 2018-06-15 | 2018-11-13 | 深圳臻迪信息技术有限公司 | Adjust the method, apparatus and unmanned machine system of antenna |
| CN109346845A (en) * | 2018-09-14 | 2019-02-15 | 中国联合网络通信集团有限公司 | Antenna adjusting method, device, equipment, UAV system and readable storage medium storing program for executing |
| CN109444809A (en) * | 2018-10-30 | 2019-03-08 | 天津津航计算技术研究所 | A kind of UAV TT & C's method based on smart antenna |
| WO2019133049A1 (en) * | 2017-12-30 | 2019-07-04 | Intel Corporation | Handover-related technology, apparatuses, and methods |
| CN110176955A (en) * | 2019-07-01 | 2019-08-27 | 北京有感科技有限责任公司 | UAV Communication base station, communication system and communication system construction method |
| KR20190106949A (en) * | 2019-08-31 | 2019-09-18 | 엘지전자 주식회사 | Intelligent beamforming method, apparatus and intelligent computing device |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI656758B (en) * | 2017-12-01 | 2019-04-11 | 財團法人工業技術研究院 | Communication terminal device for aircraft and mobile communication method thereof |
-
2019
- 2019-09-30 CN CN201910943226.8A patent/CN110635831B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2019133049A1 (en) * | 2017-12-30 | 2019-07-04 | Intel Corporation | Handover-related technology, apparatuses, and methods |
| CN108808243A (en) * | 2018-06-15 | 2018-11-13 | 深圳臻迪信息技术有限公司 | Adjust the method, apparatus and unmanned machine system of antenna |
| CN109346845A (en) * | 2018-09-14 | 2019-02-15 | 中国联合网络通信集团有限公司 | Antenna adjusting method, device, equipment, UAV system and readable storage medium storing program for executing |
| CN109444809A (en) * | 2018-10-30 | 2019-03-08 | 天津津航计算技术研究所 | A kind of UAV TT & C's method based on smart antenna |
| CN110176955A (en) * | 2019-07-01 | 2019-08-27 | 北京有感科技有限责任公司 | UAV Communication base station, communication system and communication system construction method |
| KR20190106949A (en) * | 2019-08-31 | 2019-09-18 | 엘지전자 주식회사 | Intelligent beamforming method, apparatus and intelligent computing device |
Non-Patent Citations (1)
| Title |
|---|
| 无人机通信多路并行自适应传输系统的设计与实现;李子园;《信息化研究》;20190831;第45卷(第4期);全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110635831A (en) | 2019-12-31 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110635831B (en) | FDMA-based unmanned aerial vehicle measurement and control cellular communication method | |
| US11241969B2 (en) | Unmanned aerial vehicle drive testing and mapping of carrier signals | |
| CN110650432B (en) | Unmanned aerial vehicle measurement and control cellular communication method based on MF-TDMA | |
| US10623086B2 (en) | Dynamic shielding system of cellular signals for an antenna of an unmanned aerial vehicle | |
| CN110635830B (en) | Unmanned aerial vehicle measurement and control cellular communication method based on TS-ALOHA | |
| CN110649961B (en) | Unmanned aerial vehicle measurement and control cellular communication method based on DA-TDMA | |
| CN110677917B (en) | Unmanned aerial vehicle measurement and control cellular communication method based on CS-ALOHA | |
| KR101822369B1 (en) | High-capacity hybrid terrestrial/satellite cellular radio communication system | |
| JPH10509287A (en) | Wireless telephone distribution system with time and space diversity transmission | |
| JP2019047262A (en) | LEO communication terminal, LEO communication service system, program for LEO communication terminal, and LEO communication terminal power saving control method | |
| CN110649939B (en) | Unmanned aerial vehicle measurement and control cellular communication method based on MF-CDMA | |
| CN112866971A (en) | Satellite fusion unmanned aerial vehicle carries on aerial to ground networking system of 4G communication base station | |
| CN114067548A (en) | Mutual backup dual-link communication method for rotor unmanned aerial vehicle | |
| US20230073733A1 (en) | User equipment location determination using different coverage types | |
| CN113596775A (en) | Unmanned aerial vehicle communication system | |
| JP2024010185A (en) | Antenna system and data processing method | |
| EP3957124A1 (en) | Integrated access and backhaul from high altitude platforms | |
| CN110366102B (en) | Unmanned aerial vehicle cellular communication distributed base station selection method based on position information | |
| CN101001472A (en) | Two-way heterogeneous broadcast network | |
| CN107154819A (en) | A kind of satellite relay selection optimization method based on geographical location information | |
| CN113556189A (en) | Antenna adjusting method and device for unmanned aerial vehicle | |
| CN110430537B (en) | Unmanned aerial vehicle cellular communication base station selection method based on position information | |
| Xue et al. | Connected aerials | |
| CN110417457B (en) | Unmanned aerial vehicle cellular communication base station selection method based on sliding window counting | |
| CN110312295B (en) | Unmanned aerial vehicle cellular communication base station selection method based on distributed sliding window counting |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |