Emergency communication coverage system for power industry

Abstract

The present invention relates to an emergency communication coverage system applied to the electric power field, including: a base station subsystem, an unmanned aerial vehicle subsystem, and a UE subsystem. The base station subsystem is used to provide access services for unmanned aerial vehicle relays, the unmanned aerial vehicle subsystem is used to provide relay services for UE subsystems to access the base station subsystem, and the UE subsystem is used to access the base station subsystem through the unmanned aerial vehicle subsystem to provide electric power communication services. The present invention introduces relays and deploys them based on relay self-organization, efficiently utilizes the existing network to build a coverage system for emergency communications, and effectively meets the requirements of quickly building an efficient network for emergency communications.

Description

Technical Field

[0001] The present invention relates to the field of mobile communications, and in particular to an emergency communication coverage system applied to the field of electric power. Background Art

[0002] During the operation of the power system, refined management and remote guidance and assistance are particularly important. In each link of the emergency response of power operations, various information from the incident scene is quickly collected to the command center as a basis for analysis and judgment by experts and leaders, thereby ensuring smooth and efficient communication between the command center and front-line personnel, which is conducive to the realization of flat and integrated command and dispatch management, and reducing the burden on on-site operators.

[0003] However, due to the certain danger of core power equipment, related equipment is often deployed in remote or hidden places to eliminate the concerns about the impact of equipment operation on people's daily life. Correspondingly, it brings more difficult challenges to the emergency communication of the power system, such as insufficient coverage of the surrounding site, difficulty in setting up emergency communication vehicles in the surrounding area, and insufficient wired backhaul resources. As a result, the industry has derived a power emergency communication system solution with VSAT satellite communication network as the core, maritime satellite communication system as the supplement, combined with short-wave communication and vehicle-mounted short-range access system to achieve close communication between the site and the command center. However, due to the slow response speed and limited bandwidth of satellite communication, it has brought troubles to the communication between the command center and the front-line personnel. Due to site limitations, short-wave communication and vehicle-mounted communication are often difficult to independently provide sufficient coverage for the power emergency communication site. Therefore, how to build a power emergency communication system with fast response speed, bandwidth and sufficient coverage is a problem to be solved by the industry. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide an emergency communication coverage system applied to the electric power field.

[0005] The technical solution adopted by the present invention to solve the problems existing in the prior art is:

[0006] The present invention provides an emergency communication coverage system applied to the electric power field, which is characterized by comprising: a base station subsystem, an unmanned aerial vehicle subsystem, and a UE subsystem; the base station subsystem: providing access services for unmanned aerial vehicle relays; the unmanned aerial vehicle subsystem: providing relay services for UE subsystems to access the base station subsystem; the UE subsystem: the UE subsystem: accesses the base station subsystem through the unmanned aerial vehicle subsystem to provide electric power communication services; the steps of the base station subsystem, the unmanned aerial vehicle subsystem, and the UE subsystem cooperating with each other to perform emergency communication coverage are as follows:

[0007] Step 1: The UAV subsystem measures the base station and the terminal based on the preset d azimuth indexes and N position points under each azimuth index to obtain the base station set measurement information MeasureBS d,p,i and terminal measurement information MeasureUE d,p , where d is the azimuth index, ranging from 1, ..., M, p is the position index under azimuth index d, ranging from 1, ..., N, and i is the base station index measured under position index p under azimuth index d, ranging from 1, ..., MaxBS d,p ;

[0008] Step 2: Drone Subsystems from Select the best base station BestBS from the base stations;

[0009] Step 3: The UAV subsystem calculates the location information of the BestBS and UE based on the measurement information;

[0010] Step 4: The UAV subsystem corrects the path loss model between the UAV and BestBS, and between the UAV and UE according to the location information and measurement information;

[0011] Step 5: The UAV subsystem calculates the candidate spatial range S of the UAV as a communication relay between the BestBS and the UE;

[0012] Step 6: The UAV subsystem searches for the optimal relay location point for the UE to access the BestBS within the range of S, and hovers at the location point to provide relay services for emergency communications.

[0013] Preferably, the drone subsystem includes: a reference position planning module, a measurement module, a base station selection module, a positioning module, a path loss correction module, an alternative space determination module, an optimal relay position point determination module, and a suspended relay service module. The functions of each module are as follows: a reference position planning module: dividing the azimuth index and the measurement reference position point information under each azimuth index according to the M value and the N value; a measurement module: measuring the base station and the UE according to each measurement reference position point under each azimuth index to generate measurement information; a base station selection module: selecting the best base station BestBS and the corresponding azimuth index and the measurement reference position point within the azimuth index according to the measurement information; a positioning module: calculating the UE and The location information of BestBS; the path loss correction module: according to the difference between the actual path loss value and the theoretical path loss value, the path loss correction value Delta is calculated to form a path loss correction model; the alternative space determination module: according to the path loss correction model, the transmission power and the minimum receiving power, the effective communication space S_UE between the UE and the UAV and the effective communication space S_BS between the UAV and the base station are calculated, and then the intersection of S_UE and S_BS is determined as the alternative space S; the optimal relay position point determination module: according to the communication quality, the optimal relay position point is selected from the range of the alternative space S; the floating relay service module: controls the UAV to float to the optimal relay position point to provide relay service for the communication between the UE and the BestBS.

[0014] Preferably, in step 1, the value of M is 4, representing 4 azimuth angles, each azimuth is 90 degrees; the value of N is determined by the positioning algorithm, that is, the positioning algorithm needs to measure the measurement of K reference position points to assist the positioning operation, then the value of N is greater than or equal to the value of K, and the method for determining the N position points in each of the M azimuths is:

[0015] Step 1.1, determine the take-off position point P0, where the position point P0 is the position of the UE;

[0016] Step 1.2, calculate the communication radius R0 with P0 according to the UE transmission power, the drone boundary receiving power and the free propagation loss in space;

[0017] Step 1.3, determine the intersection of the coverage space with P0 as the center and R0 as the radius and the plane with a height of H0 as the candidate area S0, where H0 is the effective communication height covered by the base station;

[0018] Step 1.4, divide S0 into M equal parts, each part corresponds to an orientation index, and select N non-overlapping reference position points in each orientation index as the position points corresponding to the position index p in the orientation index d.

[0019] Preferably, in step 2, the method for selecting the best base station BestBS is:

[0020] Step 2.1, select a position index t that has not been determined;

[0021] Step 2.2: Determine whether more than or equal to K reference position points among the N reference position points of the position index t can receive the UE signal. If yes, jump to step 2.3; if not, jump to step 2.5;

[0022] Step 2.3, clear queue B0, and write the base station indexes of the N reference position points of azimuth index t that can receive base station signals at more than or equal to K reference position points into queue B0;

[0023] Step 2.4, obtain the quality values ​​of N position points of each base station in B0 under the azimuth index t, select the best quality value, and write the base station index, azimuth index, position index, and quality value corresponding to the best quality value into the queue Q0;

[0024] Step 2.5: Determine whether all orientation indexes have been completed. If yes, jump to step 2.6; if no, jump to step 2.1;

[0025] Step 2.6: Select the base station index, direction index, and location index with the best quality from the queue Q0. The base station corresponding to the base station index is the BestBS.

[0026] Preferably, in step 3, the method for calculating the location information of the BestBS and the UE adopts any one of the AOA+TA positioning method, the TDOA positioning method, and the fingerprint positioning method.

[0027] Preferably, in step 4, the method for correcting the path loss model of the drone and the BestBS is:

[0028] Step 4.1, according to the position of the UAV P_plane and the position of the base station P_BS, calculate the distance Distance_plane between the UAV and the base station;

[0029] Step 4.2, according to the communication frequency F and distance Distance_plane between the UAV and the base station, the ideal path loss value PathLoss_ideal is calculated using the spatial free loss model;

[0030] Step 4.3: According to the actual transmission path loss value PathLoss_fact between the drone and the base station, which is obtained by subtracting the receiving power of the drone from the base station transmission power, calculate PathLoss_fact minus PathLoss_ideal to get the Delta value;

[0031] Step 4.4, add the Delta value to the free space path loss model for communication between the drone and the base station, that is, the path loss value calculated in free space plus Delta is the corrected path loss value;

[0032] The method for correcting the path loss model between the drone and the UE is the same as the method for correcting the path loss model between the drone and the base station.

[0033] Preferably, in step 5, the calculation method of the candidate space range S is:

[0034] Step 5.1, calculate the effective communication space S_BS between the UAV and the base station;

[0035] Step 5.2, calculate the effective communication space S_UE between the UAV and the UE;

[0036] Step 5.3: The spatial intersection of S_BS and S_UE is the candidate spatial range S.

[0037] Preferably, in step 5.1, the specific method for calculating the effective communication space S_BS between the drone and the base station is:

[0038] Step 5.1.1, according to the transmission rate requirement, look up the table to get the minimum power value PWR_min of BestBS receiving drone;

[0039] Step 5.1.2, according to the UAV transmission power PWR_tx and PWR_min, based on the modified path loss model, calculate the transmission distance R1;

[0040] Step 5.1.3, with the location of the base station as the center and the radius as R1, calculate the effective space S_BS between the drone and the base station that meets the transmission rate requirements;

[0041] In step 5.2, the method for calculating the effective communication space S_UE between the drone and the UE is the same as the method for calculating the effective communication space S_BS between the drone and the base station;

[0042] In step 5.3, based on the three-dimensional map or radar detection, the candidate spatial range S is obtained by deleting the spatial area of ​​non-line-of-sight transmission from the spatial intersection of S_BS and S_UE.

[0043] Preferably, in step 6, the method for finding the optimal relay location point is:

[0044] Step 6.1, divide the candidate space range S into X subspaces;

[0045] Step 6.2, find out the subspace that has not been measured from the X subspaces, assuming that the subspace is numbered F;

[0046] Step 6.3, the drone subsystem flies to any coordinate in the space with subspace number F to measure the signal between the drone and the base station to obtain the quality value M1, and the signal between the drone and the UE to obtain the quality value M2, select the value with the worst quality from M1 and M2, and write the value and the corresponding subspace number F into the queue T;

[0047] Step 6.4: Determine whether the X-molecule space has completed all the measurements between the drone and the base station, and between the drone and the UE. If yes, jump to step 6.5; if not, jump to step 6.2;

[0048] Step 6.5: Select the subspace with the best quality from the queue T. The coordinate point in the subspace is the optimal relay position point.

[0049] Preferably, in step 6.3, the drone subsystem flies to the center coordinate of the subspace numbered F to measure the mass values ​​M1 and M2;

[0050] In step 6.5, the optimal relay position point is the center coordinate in the subspace with the best quality.

[0051] Compared with the prior art, the present invention has the following beneficial effects:

[0052] The present invention introduces relays and deploys them based on relay self-organization, efficiently utilizing the existing network to build a coverage system for emergency communications, and effectively meeting the requirements for quickly building an efficient network for emergency communications. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0054] Figure 1 is a schematic diagram of a method flow of an embodiment of the present invention;

[0055] Figure 2 This is a schematic diagram of the structure of a drone subsystem according to an embodiment of the present invention;

[0056] Figure 3 It is a schematic diagram of an implementation of an embodiment of the present invention. DETAILED DESCRIPTION

[0057] In order to make the technical solutions and beneficial effects of the present invention clearer, the embodiments of the present invention are further explained in detail below.

[0058] like Figures 1 to 3 As shown, the present invention provides an emergency communication coverage system applied to the electric power field, characterized in that it includes: a base station subsystem, a drone subsystem, and a UE subsystem;

[0059] Base station subsystem: provides access services for drone relays;

[0060] UAV subsystem: provides relay services for UE subsystem to access base station subsystem;

[0061] UE subsystem: UE subsystem: accesses the base station subsystem through the drone subsystem to provide power communication services;

[0062] The steps of the base station subsystem, the drone subsystem, and the UE subsystem cooperating with each other to provide emergency communication coverage are as follows:

[0063] Step 1: The UAV subsystem measures the base station and the terminal based on the preset d azimuth indexes and N position points under each azimuth index to obtain the base station set measurement information MeasureBS d,p,i and terminal measurement information MeasureUE d,p , where d is the azimuth index, ranging from 1, ..., M, p is the position index under azimuth index d, ranging from 1, ..., N, and i is the base station index measured under position index p under azimuth index d, ranging from 1, ..., MaxBS d,p ;

[0064] Step 2: Drone Subsystems from Select the best base station BestBS from the base stations;

[0065] Step 3: The UAV subsystem calculates the location information of the BestBS and UE based on the measurement information;

[0066] Step 4: The UAV subsystem corrects the path loss model between the UAV and BestBS, and between the UAV and UE according to the location information and measurement information;

[0067] Step 5: The UAV subsystem calculates the candidate spatial range S of the UAV as a communication relay between the BestBS and the UE;

[0068] Step 6: The UAV subsystem searches for the optimal relay location point for the UE to access the BestBS within the range of S, and hovers at the location point to provide relay services for emergency communications.

[0069] The present invention also provides an emergency communication coverage method applied to the power field as shown in steps 1 to 6.

[0070] The UE subsystem is the terminal subsystem, UE refers to the terminal, and the N location points in step 1 are the same concept as the reference location points. The measurement information in steps 3 and 4 includes base station set measurement information MeasureBS d,p,i and terminal measurement information MeasureUE d,p .

[0071] The UAV subsystem includes: a reference position planning module, a measurement module, a base station selection module, a positioning module, a path loss correction module, an alternative space determination module, an optimal relay position point determination module, and a suspended relay service module. The functions of each module are as follows:

[0072] Reference location planning module: This module determines the candidate area S0 according to the take-off point and coverage radius of the drone and the effective coverage height of the base station, and then divides the azimuth index and the measurement reference location point information under each azimuth index according to the M value and N value;

[0073] Measurement module: This module measures the base station and UE at each measurement reference position point under each azimuth index;

[0074] Base station selection module: This module selects the best base station BestBS and the corresponding azimuth index and reference position point within the azimuth index according to the measurement information of the measurement module;

[0075] Positioning module: This module is responsible for calculating the location information of UE and BestBS based on the measurement information;

[0076] Road loss correction module: This module calculates the road loss correction value Delta based on the difference between the actual road loss value and the theoretical road loss value to form a road loss correction model;

[0077] Alternative space determination module: This module calculates the effective communication space S_UE between UE and UAV and the effective communication space S_BS between UAV and base station based on the modified path loss model, transmission power and minimum receiving power requirements, and then determines the intersection of S_UE and S_BS as the alternative space;

[0078] Optimal relay location point determination module: This module divides the candidate space into X subspaces, and then measures the quality values ​​of the drone and the base station, and the drone and the UE in each subspace, and selects the worst quality as the communication quality value of the subspace. Finally, the best subspace is selected from the X subspaces as the optimal relay subspace, and the position point in the optimal relay subspace is used as the optimal relay location point;

[0079] Suspended relay service module: This module is responsible for suspending to the optimal relay position point and providing relay service for the communication between UE and BestBS.

[0080] In step 1, the value of M is 4, representing 4 azimuth angles, each azimuth is 90 degrees; the value of N is determined by the positioning algorithm, that is, the positioning algorithm needs to measure the measurement of K reference position points to assist the positioning operation, then the value of N is greater than or equal to the value of K, and the method for determining the N position points in each of the M azimuths is:

[0081] Step 1.1, determine the take-off position point P0, where the position point P0 is the position of the UE;

[0082] Step 1.2, calculate the communication radius R0 with P0 according to the UE transmission power, the drone boundary receiving power and the free propagation loss in space;

[0083] Step 1.3, determine the intersection of the coverage space with P0 as the center and R0 as the radius and the plane with a height of H0 as the candidate area S0, where H0 is the effective communication height covered by the base station;

[0084] Step 1.4, divide S0 into M equal parts, each part corresponds to an orientation index, and select N non-overlapping reference position points in each orientation index as the position points corresponding to the position index p in the orientation index d.

[0085] Steps 1.1 to 1.4 are performed by the reference position planning module. In step 1.2, the drone boundary receiving power is the minimum power at which the drone can receive and identify UE signals. According to the UE transmission power, the drone receives the minimum power requirement of the UE, and then based on the free space propagation model, the communication transmission radius R0 between the UE and the drone is calculated. In step S1.3, the candidate area S0 is a circle formed by the intersection of a spherical space with P0 as the center and R0 as the radius and the horizontal plane with a height of H0.

[0086] In step 2, the method for selecting the best base station BestBS is:

[0087] Step 2.1, select a position index t that has not been determined;

[0088] Step 2.2: Determine whether more than or equal to K reference position points among the N reference position points of the position index t can receive the UE signal. If yes, jump to step 2.3; if not, jump to step 2.5;

[0089] Step 2.3, clear queue B0, and write the base station indexes of the N reference position points of azimuth index t that can receive base station signals at more than or equal to K reference position points into queue B0;

[0090] Step 2.4, obtain the quality values ​​of N position points of each base station in B0 under the azimuth index t, select the best quality value, and write the base station index, azimuth index, position index, and quality value corresponding to the best quality value into the queue Q0;

[0091] Step 2.5: Determine whether all orientation indexes have been completed. If yes, jump to step 2.6; if no, jump to step 2.1;

[0092] Step 2.6: Select the base station index, direction index, and location index with the best quality from the queue Q0. The base station corresponding to the base station index is the BestBS.

[0093] Steps 2.1 to 2.6 are performed by the base station selection module. The quality value in step 2.4 is determined by the measurement module measuring the received power or signal-to-noise ratio of the signal transmitted by the base station received by the drone at N position points under the azimuth index t of each base station. Preferably, the quality value can be comprehensively determined by multiple methods such as RSRP, SINR, RSSI, and RSRQ. The RSRP is the reference signal received power, the SINR is the signal to interference plus noise ratio, the RSRQ is the reference signal received quality, and the RSSI is the received signal strength indication, which is an optional part of the wireless transmission layer and is used to determine the link quality and whether to increase the broadcast transmission strength. Received power or signal-to-noise ratio.

[0094] In the step 3, the method for calculating the location information of the BestBS and the UE adopts any one of the AOA+TA positioning method, the TDOA positioning method, and the fingerprint positioning method, and the positioning module calculates the location information of the UE and the BestBS according to the measurement information provided by the measurement module.

[0095] The measurement quantities involved in the fingerprint positioning method are received power, TDOA (time difference of arrival), the measurement quantity involved is timing advance, and the measurement quantities involved in AOA+TA (angle of arrival + timing advance) are angle of arrival and timing advance. The fingerprint positioning algorithm is a set of algorithms proposed based on the complex indoor environment and the different signal strength information formed at different locations due to signal reflection and refraction. The fingerprint algorithm can make good use of the signal information formed by reflection and refraction. The fingerprint signal strength database is first generated offline, and the position distance is calculated through a set of RSSI values ​​(Received Signal Strength Indication) actually measured in online positioning.

[0096] TDOA positioning is a method of positioning using time difference. By measuring the time it takes for a signal to reach a monitoring station, the distance of the signal source can be determined. Using the distance from the signal source to each monitoring station (using the monitoring station as the center and the distance as the radius to draw a circle), the position of the signal can be determined. However, absolute time is generally difficult to measure. By comparing the absolute time difference of the signal reaching each monitoring station, a hyperbola with the monitoring station as the focus and the distance difference as the major axis can be drawn. The intersection of the hyperbola is the position of the signal.

[0097] The AOA positioning method mainly measures the arrival angle of the signal between the mobile station and the base station. The ray formed with the base station as the starting point must pass through the mobile station, and the intersection of the two rays is the position of the mobile station. This method only requires two base stations to determine the estimated position of the MS; the TA+AoA positioning method is usually only used for network-based positioning. The main reason is that AoA can only be measured by the base station, that is, all the measurement quantities related to this positioning method are provided by the base station. These measurement quantities can be provided by the base station to the positioning server, so the purpose of positioning can be achieved by supporting network-based positioning. Therefore, this also brings an advantage of this method, that is, for terminals that do not support positioning services, they can also be positioned by this method.

[0098] In step 4, the method for correcting the UAV and BestBS path loss model is:

[0099] Step 4.1, according to the position of the UAV P_plane and the position of the base station P_BS, calculate the distance Distance_plane between the UAV and the base station;

[0100] Step 4.2, according to the communication frequency F and distance Distance_plane between the UAV and the base station, the ideal path loss value PathLoss_ideal is calculated using the spatial free loss model;

[0101] Step 4.3: According to the actual transmission path loss value PathLoss_fact between the drone and the base station, which is obtained by subtracting the receiving power of the drone from the base station transmission power, calculate PathLoss_fact minus PathLoss_ideal to get the Delta value;

[0102] Step 4.4: Add the Delta value to the free space path loss model for communication between the UAV and the base station. That is, the path loss value calculated in free space plus Delta is the corrected path loss value.

[0103] The method for correcting the path loss model between the UAV and the UE is the same as the method for correcting the path loss model between the UAV and the base station, which is as follows:

[0104] Step 4.1a, according to the position of the UAV P_plane1 and the position of the UE P_BS, calculate the distance Distance_plane1 between the UAV and the terminal UE;

[0105] Step 4.2a, according to the communication frequency F1 and distance Distance_plane1 between the UAV and the UE, the ideal path loss value PathLoss_ideal1 is calculated using the spatial free loss model;

[0106] Step 4.3a, according to the actual transmission path loss value PathLoss_fact1 between the drone and the UE, which is the UE transmit power minus the drone receive power, calculate PathLoss_fact1 minus PathLoss_ideal1 to get the Delta1 value;

[0107] Step 4.4a: Add the Delta1 value to the free space path loss model for communication between the UAV and the UE. That is, the path loss value calculated in free space plus Delta1 is the corrected path loss value.

[0108] The steps 4.1 to 4.4 and steps 4.1a to 4.4a are all executed by the road loss correction module.

[0109] In step 5, the calculation method of the candidate space range S is:

[0110] Step 5.1, calculate the effective communication space S_BS between the UAV and the base station;

[0111] Step 5.2, calculate the effective communication space S_UE between the UAV and the UE;

[0112] Step 5.3: The spatial intersection of S_BS and S_UE is the candidate spatial range S.

[0113] In step 5.1, the specific method for calculating the effective communication space S_BS between the drone and the base station is:

[0114] Step 5.1.1, according to the transmission rate requirement, look up the table to get the minimum power value PWR_min of BestBS receiving drone;

[0115] Step 5.1.2, according to the UAV transmission power PWR_tx and PWR_min, based on the modified path loss model, calculate the transmission distance R1;

[0116] Step 5.1.3: With the location of the base station as the center and a radius of R1, calculate the effective space S_BS between the drone and the base station that meets the transmission rate requirements.

[0117] In step 5.2, the method for calculating the effective communication space S_UE between the drone and the UE is the same as the method for calculating the effective communication space S_BS between the drone and the base station, which is as follows:

[0118] Step 5.2.1, according to the transmission rate requirement, look up the table to obtain the minimum power value PWR_min1 of the UE receiving the drone;

[0119] Step 5.2.2, according to the UAV transmission power PWR_tx1 and PWR_mi1n, based on the modified path loss model, calculate the transmission distance R2;

[0120] Step 5.2.3, with the UE location as the center and a radius of R2, calculate the effective space S_UE between the UAV and the UE that meets the transmission rate requirements.

[0121] In step 5.3, based on the three-dimensional map or radar detection, the candidate spatial range S is obtained by deleting the spatial area of ​​non-line-of-sight transmission from the spatial intersection of S_BS and S_UE.

[0122] Steps 5.1 to 5.3 are performed by the candidate space determination module. The non-line-of-sight transmission refers to indirect point-to-point communication between a receiver and a transmitter. The most direct explanation of non-line-of-sight is that the line of sight between the two communicating points is blocked, and they cannot see each other, and more than 50% of the Fresnel zone is blocked.

[0123] In step 6, the method for finding the optimal relay location point is:

[0124] Step 6.1, divide the candidate space range S into X subspaces;

[0125] Step 6.2, find out the subspace that has not been measured from the X subspaces, assuming that the subspace is numbered F;

[0126] Step 6.3, the drone subsystem flies to any coordinate in the space with subspace number F to measure the signal between the drone and the base station to obtain the quality value M1, and the signal between the drone and the UE to obtain the quality value M2, select the value with the worst quality from M1 and M2, and write the value and the corresponding subspace number F into the queue T;

[0127] Step 6.4: Determine whether the X-molecule space has completed all the measurements between the drone and the base station, and between the drone and the UE. If yes, jump to step 6.5; if not, jump to step 6.2;

[0128] Step 6.5: Select the subspace with the best quality from the queue T. The coordinate point in the subspace is the optimal relay position point.

[0129] In step 6.3, the drone subsystem flies to the center coordinate of the subspace numbered F to measure the mass values ​​M1 and M2;

[0130] In step 6.5, the optimal relay position point is the center coordinate in the subspace with the best quality.

[0131] Steps 6.1 to 6.5 are executed by the optimal relay location determination module. In step 6.3, based on the barrel effect, ABC, A communicates with B, B communicates with C, and the location selection of B, to meet the communication quality requirements of AB and BC, it is necessary to ensure that the worst quality links in AB and BC can meet the requirements, and the worst ones are selected here. The measurement and judgment of the quality value in step 6.3 is the same as the measurement and judgment of the quality value in step 2.4, and will not be repeated here.

[0132] Specific implementation: Figure 3 As shown in the figure, the UAV subsystem takes off from position P0, which corresponds to the position of the UE. According to the UE transmission power, the UAV receives the minimum power requirement of the UE, and then based on the free space propagation model, that is, formula (1), the communication transmission distance R0 between the UE (P0 position) and the UAV is calculated.

[0133] Path loss = 20lg(F) + 20lg(D) + 32.4, where F is the frequency in MHz and D is the distance in km (1)

[0134] The specific calculation process is as follows:

[0135] 10lg(TX_UE)-10lg(RX_UAV_min)=20lg(F)+20lg(D)+32.4, where TX_UE is the UE transmit power, RX_UAV_min is the minimum power value of the UAV receiving the UE, and F is the frequency. The above three variables are all known values. According to formula (1), the variable D of the sphere can be obtained, which is the communication transmission distance R0 between the UE (P0 position) and the UAV.

[0136] Then, the reference position planning module of the drone subsystem determines the intersection of the coverage space with P0 as the center and R0 as the radius and the plane with the height H0 as the candidate area S0, and divides S0 into M parts (such as Figure 3 As shown: In this embodiment, the value of M is 4, the upper left corner is the orientation index 1, the lower left corner is the orientation index 2, the lower right corner is the orientation index 3, and the upper right corner is the orientation index 4), each portion corresponds to an orientation index, and N non-overlapping reference position points are selected in each orientation index (such as Figure 3 As shown: This embodiment adopts the TDOA positioning method, which requires three reference position measurements, N is 3, and the 12 points belong to azimuth index 1, azimuth index 2, azimuth index 3, and azimuth index 4 respectively;

[0137] Then the drone subsystem measurement module measures the UE measurement quantity and base station measurement quantity measured at each reference position point under each azimuth index;

[0138] Then the base station selection module of the drone subsystem selects BestBS according to the measurement amount. In this embodiment, it is assumed that only the base station signal (base station 1, base station 2) is measured by azimuth index 1, and the base stations cannot be measured by other azimuth indexes, and the three reference position points of azimuth index 1 can all receive the signal of UE, the signal of base station 1, and the signal of base station 2. Then, from {azimuth index 1, position index 1, base station 1}, {azimuth index 1, position index 2, base station 1}, {azimuth index 1, position index 3, base station 1}, {azimuth index 1, position index 1, base station 2}, {azimuth index 1, position index 2, base station 2}, {azimuth index 1, position index 3, base station 2}, find a group with the best quality, and determine the base station index corresponding to the group as BestBS;

[0139] Then, the UAV subsystem positioning module Figure 3 The measurement values ​​of the three positions belonging to the orientation index 1 about the BestBS are used to calculate the position information of the BestBS;

[0140] Then, the UAV subsystem path loss correction module calculates the ideal path loss value PathLoss_ideal (refer to formula (1)) based on the distance and working frequency, and obtains the actual transmission path loss value PathLoss_fact based on the BestBS transmission power minus the UAV receiving BestBS power. The Delta value is calculated by subtracting PathLoss_ideal from PathLoss_fact, and the path loss model between the UAV and the base station is corrected to formula (2)

[0141] Path loss = 20lg(F)+20lg(D)+32.4+Delta, where F is the frequency in MHz and D is the distance in km(2)

[0142] The method for correcting the path loss model between the UAV and the UE is the same as the method for correcting the path loss model between the UAV and the base station, and will not be repeated here. The UAV subsystem candidate space determination module calculates the intersection of S_BS and S_UE according to steps 5.1 to 5.3, and the intersection is the candidate space;

[0143] Then, the optimal relay position point determination module of the drone subsystem calculates the optimal relay position point according to steps 6.1 to 6.5;

[0144] Ideally, the drone flies to the optimal relay location, hovers at that location, and provides relay services for the UE subsystem to access the base station subsystem, thereby quickly utilizing the existing network to build an efficient coverage network that meets performance requirements for power communication. The entire coverage system is self-organized by the drone subsystem without the need for human intervention, with high efficiency and fast network construction speed.

[0145] From the above embodiments, it can be seen that by adopting the method of the present invention, by introducing relays and deploying them based on relay self-organization, the existing network can be efficiently used to build a coverage system for emergency communications, effectively meeting the requirements of quickly building an efficient network for emergency communications.

[0146] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. Emergency communication coverage system applied in the power field, characterized by: include: Base station subsystem, UAV subsystem, UE subsystem; Base station subsystem: provides access services for drone relays; UAV subsystem: provides relay services for UE subsystem to access base station subsystem; UE subsystem: accesses the base station subsystem through the drone subsystem to provide power communication services; The steps of the base station subsystem, the drone subsystem, and the UE subsystem cooperating with each other to provide emergency communication coverage are as follows: Step 1: The UAV subsystem measures the base station and the terminal based on the preset d azimuth indexes and N position points under each azimuth index to obtain the base station set measurement information MeasureBS d,p,i and terminal measurement information MeasureUE d,p , where d is the azimuth index, ranging from 1, ..., M, p is the position index under azimuth index d, ranging from 1, ..., N, and i is the base station index measured under position index p under azimuth index d, ranging from 1, ..., MaxBS d,p ; Step 2: Drone Subsystems from Select the best base station BestBS from the base stations; Step 3: The UAV subsystem calculates the location information of the BestBS and UE based on the measurement information; Step 4: The UAV subsystem corrects the path loss model between the UAV and BestBS, and between the UAV and UE according to the location information and measurement information; Step 5: The UAV subsystem calculates the candidate spatial range S of the UAV as a communication relay between the BestBS and the UE; Step 6: The UAV subsystem searches for the optimal relay location point for the UE to access the BestBS within the range of S, and hovers at the location point to provide relay services for emergency communications; In step 1, the value of M is 4, representing 4 azimuth angles, each azimuth is 90 degrees; the value of N is determined by the positioning algorithm, that is, the positioning algorithm needs to measure the measurement of K reference position points to assist the positioning operation, then the value of N is greater than or equal to the value of K, and the method for determining the N position points in each of the M azimuths is: Step 1.1, determine the take-off position point P0, where the position point P0 is the position of the UE; Step 1.2, calculate the communication radius R0 with P0 according to the UE transmission power, the drone boundary receiving power and the free propagation loss in space; Step 1.3, determine the intersection of the coverage space with P0 as the center and R0 as the radius and the plane with a height of H0 as the candidate area S0, where H0 is the effective communication height covered by the base station; Step 1.4, divide S0 into M equal parts, each part corresponds to an orientation index, and select N non-overlapping reference position points in each orientation index as the position points corresponding to position index p in orientation index d; In step 2, the method for selecting the best base station BestBS is: Step 2.1, select a position index t that has not been determined; Step 2.2: Determine whether more than or equal to K reference position points among the N reference position points of the position index t can receive the UE signal. If yes, jump to step 2.3; if not, jump to step 2.5; Step 2.3, clear queue B0, and write the base station indexes of the N reference position points of azimuth index t that can receive base station signals at more than or equal to K reference position points into queue B0; Step 2.4, obtain the quality values ​​of N position points of each base station in B0 under the azimuth index t, select the best quality value, and write the base station index, azimuth index, position index, and quality value corresponding to the best quality value into the queue Q0; Step 2.5: Determine whether all orientation indexes have been completed. If yes, jump to step 2.6; if no, jump to step 2.1; Step 2.6: Select the base station index, direction index, and location index with the best quality from the queue Q0. The base station corresponding to the base station index is the BestBS. In step 3, the method for calculating the location information of the BestBS and the UE adopts any one of the AOA+TA positioning method, the TDOA positioning method, and the fingerprint positioning method; In step 4, the method for correcting the UAV and BestBS path loss model is: Step 4.1, according to the position of the UAV P_plane and the position of the base station P_BS, calculate the distance Distance_plane between the UAV and the base station; Step 4.2, according to the communication frequency F and distance Distance_plane between the UAV and the base station, the ideal path loss value PathLoss_ideal is calculated using the spatial free loss model; Step 4.3: According to the actual transmission path loss value PathLoss_fact between the drone and the base station, which is obtained by subtracting the receiving power of the drone from the base station transmission power, calculate PathLoss_fact minus PathLoss_ideal to get the Delta value; Step 4.4, add the Delta value to the free space path loss model for communication between the drone and the base station, that is, the path loss value calculated in free space plus Delta is the corrected path loss value; The method for correcting the path loss model between the UAV and the UE is the same as the method for correcting the path loss model between the UAV and the base station; In step 5, the calculation method of the candidate space range S is: Step 5.1, calculate the effective communication space S_BS between the UAV and the base station; Step 5.2, calculate the effective communication space S_UE between the UAV and the UE; Step 5.3: The spatial intersection of S_BS and S_UE is the candidate spatial range S; In step 5.1, the specific method for calculating the effective communication space S_BS between the drone and the base station is: Step 5.1.1, according to the transmission rate requirement, look up the table to get the minimum power value PWR_min of BestBS receiving drone; Step 5.1.2, according to the UAV transmission power PWR_tx and PWR_min, based on the modified path loss model, calculate the transmission distance R1; Step 5.1.3, with the location of the base station as the center and the radius as R1, calculate the effective space S_BS between the drone and the base station that meets the transmission rate requirements; In step 5.2, the method for calculating the effective communication space S_UE between the drone and the UE is the same as the method for calculating the effective communication space S_BS between the drone and the base station; In step 5.3, based on the three-dimensional map or radar detection, the spatial area of ​​non-line-of-sight transmission is deleted from the spatial intersection of S_BS and S_UE to obtain the candidate spatial range S; In step 6, the method for finding the optimal relay location point is: Step 6.1, divide the candidate space range S into X subspaces; Step 6.2, find out the subspace that has not been measured from the X subspaces, assuming that the subspace is numbered F; Step 6.3, the drone subsystem flies to any coordinate in the space with subspace number F to measure the signal between the drone and the base station to obtain the quality value M1, and the signal between the drone and the UE to obtain the quality value M2, select the value with the worst quality from M1 and M2, and write the value and the corresponding subspace number F into the queue T; Step 6.4: Determine whether the X-molecule space has completed all the measurements between the drone and the base station, and between the drone and the UE. If yes, jump to step 6.5; if not, jump to step 6.2; Step 6.5: Select the subspace with the best quality from the queue T. The coordinate point in the subspace is the optimal relay position point.

2. The emergency communication coverage system applied to the electric power field according to claim 1 is characterized in that: The UAV subsystem includes: a reference position planning module, a measurement module, a base station selection module, a positioning module, a path loss correction module, an alternative space determination module, an optimal relay position point determination module, and a suspended relay service module. The functions of each module are as follows: Reference location planning module: divides the azimuth index and the measurement reference location point information under each azimuth index according to the M value and N value; Measurement module: measures the base station and UE according to each measurement reference position point under each azimuth index and generates measurement information; Base station selection module: selects the best base station BestBS and the corresponding azimuth index and the measurement reference position point within the azimuth index according to the measurement information; Positioning module: calculates the location information of UE and BestBS based on the measurement information; Road loss correction module: According to the difference between the actual road loss value and the theoretical road loss value, the road loss correction value Delta is calculated to form a road loss correction model; Alternative space determination module: According to the path loss correction model, transmission power and minimum receiving power, the effective communication space S_UE between UE and UAV and the effective communication space S_BS between UAV and base station are calculated, and then the intersection of S_UE and S_BS is determined as the alternative space S; Optimal relay location point determination module: selects the optimal relay location point from the candidate space S according to the communication quality; Suspended relay service module: controls the drone to suspend to the optimal relay position and provides relay service for the communication between UE and BestBS.

3. The emergency communication coverage system applied to the electric power field according to claim 1 is characterized in that: In step 6.3, the drone subsystem flies to the center coordinate of the subspace numbered F to measure the mass values ​​M1 and M2; In step 6.5, the optimal relay position point is the center coordinate in the subspace with the best quality.

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