CN107205225B - The switching method and apparatus of unmanned aerial vehicle onboard base station based on user trajectory prediction - Google Patents
The switching method and apparatus of unmanned aerial vehicle onboard base station based on user trajectory prediction Download PDFInfo
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- CN107205225B CN107205225B CN201710656351.1A CN201710656351A CN107205225B CN 107205225 B CN107205225 B CN 107205225B CN 201710656351 A CN201710656351 A CN 201710656351A CN 107205225 B CN107205225 B CN 107205225B
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W36/00—Hand-off or reselection arrangements
- H04W36/0005—Control or signalling for completing the hand-off
- H04W36/0011—Control or signalling for completing the hand-off for data sessions of end-to-end connection
- H04W36/0016—Hand-off preparation specially adapted for end-to-end data sessions
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W36/00—Hand-off or reselection arrangements
- H04W36/0005—Control or signalling for completing the hand-off
- H04W36/0083—Determination of parameters used for hand-off, e.g. generation or modification of neighbour cell lists
- H04W36/0085—Hand-off measurements
- H04W36/0094—Definition of hand-off measurement parameters
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W36/00—Hand-off or reselection arrangements
- H04W36/16—Performing reselection for specific purposes
- H04W36/18—Performing reselection for specific purposes for allowing seamless reselection, e.g. soft reselection
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W36/00—Hand-off or reselection arrangements
- H04W36/24—Reselection being triggered by specific parameters
- H04W36/30—Reselection being triggered by specific parameters by measured or perceived connection quality data
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W36/00—Hand-off or reselection arrangements
- H04W36/24—Reselection being triggered by specific parameters
- H04W36/32—Reselection being triggered by specific parameters by location or mobility data, e.g. speed data
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Abstract
The present invention provides the switching method and apparatus for the unmanned aerial vehicle onboard base station predicted based on user trajectory, using the present invention, when mobile terminal enters the overlapping covered of current unmanned aerial vehicle onboard base station and unmanned aerial vehicle onboard base station to be selected, then by the historical track point of mobile terminal and the tracing point of current location, it is determined as the input set of prediction model；Expected trajectory point is calculated based on the regression prediction method in machine learning using prediction model；Using preset calculation formula, judge whether the first expected expected RSRP of Reference Signal Received Power RSRP and second of expected trajectory point meets mobile communication switch decision standard；If it has, then mobile terminal is switched to serving cell to be selected from current service cell.It can be realized using the present invention and quickly decide whether to need to carry out cell switching to mobile terminal, guarantee the communication quality of user.
Description
Technical field
The present invention relates to fields of communication technology, more particularly to cutting for the unmanned aerial vehicle onboard base station predicted based on user trajectory
Change method and apparatus.
Background technique
With the development of unmanned air vehicle technique, unmanned aerial vehicle onboard base station is introduced in the mobile communication network and is increasingly becoming research heat
Point.
In the prior art, Handover Management of Net-Drones for FutureInternet
The Kyung-Nam Park of Platforms, Jin-Hyeok Kang, Byeong-Moon Cho, Kyung-Joon Park and
Hwangnam Kim et al. is described a kind of method switched over using unmanned aerial vehicle onboard base station, is covered by judging in overlapping
User moving speed and direction switch in cover area to realize.
Present invention introduces machine learning methods to be reduced using the unmanned aerial vehicle onboard base station switch method based on trajectory predictions
Handover delay keeps continuity.
Summary of the invention
The purpose of the present invention is to provide the switching method and apparatus for the unmanned aerial vehicle onboard base station predicted based on user trajectory,
It quickly decides whether to need to carry out cell switching to mobile terminal to realize, guarantees the communication quality of user.Specific technical solution
It is as follows:
The invention proposes a kind of switching method of unmanned aerial vehicle onboard base station based on user trajectory prediction, the method packets
It includes:
Whether the switch decision standard based on mobile communication, detection mobile terminal come into current service cell and to be selected
Serving cell it is overlapping covered, wherein current service cell under the current unmanned aerial vehicle onboard base station and it is to be selected nobody
Serving cell to be selected under the airborne base station of machine is neighboring community, and the mobile terminal current home is in the current service cell；
If it has, then the historical track of default first quantity by the mobile terminal before reaching the current location
Point and the tracing point of the current location, are determined as the input set for the prediction model trained in advance；
Using the prediction model, default second quantity of the mobile terminal after reaching the current location is calculated
Expected trajectory point, wherein the prediction model is based on the regression prediction method in machine learning, for being existed according to mobile terminal
Into it is described it is overlapping covered before historical track point and current location tracing point, calculate mobile terminal described in the entrance
Expected trajectory point after overlapping covered；
Judge when the mobile terminal is located at any expected trajectory point, the expected trajectory point corresponding default first
It is expected that Reference Signal Received Power (Reference Signal Received Power, RSRP) and default second expected RSRP
Whether the switch decision standard of the mobile communication is met, wherein the described first expected RSRP refers to when the mobile terminal position
When the expected trajectory point, pass through the current unmanned plane machine of the calculated mobile terminal reporting of preset derivation formula
The expection RSRP of base station is carried, the described second expected RSRP refers to when the mobile terminal is located at the expected trajectory point, passes through institute
Show the expection RSRP of the unmanned aerial vehicle onboard base station to be selected of the calculated mobile terminal reporting of preset derivation formula；
If it has, then the mobile terminal is switched to the serving cell to be selected from the current service cell.
Preferably, the training process of the prediction model includes:
Obtain the corresponding track point set of mobile terminal of default third quantity, wherein the track point set includes each
Mobile terminal enter it is described it is overlapping covered before tracing point and each mobile terminal enter it is described overlapping cover
Tracing point after cover area；
The track point set is inputted into initial predicted model, training obtains the prediction model.
Preferably, default second quantity determines as follows:
Default second quantity is calculated using following formula；
In formula, k is default second quantity；TTT is preset triggering duration；△ T is default first number
Time interval between the historical track point of amount；Ceil function, which is used to return, is more than or equal to the minimum whole of specified expression formula
Number.
Preferably, in the judgement when the mobile terminal is located at any expected trajectory point, the expected trajectory point
Whether corresponding default first expected RSRP and default second expected RSRP meets the switch decision standard of the mobile communication
Before step, the method also includes:
Using following formula, calculate separately when the mobile terminal is located at each expected trajectory point, current unmanned plane
In the first distance for projecting to the mobile terminal of horizontal plane where the mobile terminal and unmanned plane to be selected in the shifting
The second distance for projecting to the mobile terminal of horizontal plane where dynamic terminal；
In formula, i=1,2；As i=1, d1It is the current unmanned plane in horizontal plane where the mobile terminal
Project to the first distance of the mobile terminal, (x1, y1) it is the current unmanned plane in horizontal plane where the mobile terminal
Projected position coordinate；As i=2, d2It is described in projecting to for horizontal plane where the mobile terminal for the unmanned plane to be selected
The second distance of mobile terminal, (x2, y2) it is that the unmanned plane to be selected is sat in the projected position of horizontal plane where the mobile terminal
Mark；(xc, yc) it is any desired guiding trajectory point coordinate；
Using following formula, according to the first distance and the second distance, calculate separately when the mobile terminal position
When each expected trajectory point, the first straight line distance of the current unmanned plane to the mobile terminal and described to be selected
Second straight line distance of the unmanned plane to the mobile terminal；
In formula, i=1,2；As i=1, s1For the current unmanned plane to the mobile terminal first straight line away from
From h1For the vertical range of horizontal plane where the current unmanned plane to the mobile terminal；As i=2, s2It is described to be selected
Second straight line distance of the unmanned plane to the mobile terminal, h2For horizontal plane where the unmanned plane to be selected to the mobile terminal
Vertical range；
It is calculated separately according to the first straight line distance and the second straight line distance when the shifting using following formula
When dynamic terminal is located at each expected trajectory point, the path loss of the first free space of the current unmanned plane and described
The path loss of second free space of unmanned plane to be selected；
FSPLi=20log log (si)+20log log(fMHZ)-27.55
In formula, i=1,2；As i=1, FSPL1For the path damage of the first free space of the current unmanned plane
Consumption；As i=2, FSPL2For the path loss of the second free space of the unmanned plane to be selected；fMHZFor the current unmanned plane
The transmitting frequency range of airborne base station and the unmanned aerial vehicle onboard base station to be selected；
Using following formula, damaged according to the path of the path loss of first free space and second free space
Consumption, calculates separately when the mobile terminal is located at each expected trajectory point, and the current unmanned plane is to the mobile terminal
When the first average path loss for being subject to and the unmanned plane to be selected send signal to the mobile terminal when sending signal by
The second average path loss arrived；
PLi=FSPLi+ηi
In formula, i=1,2；As i=1, PL1When sending signal to the mobile terminal for the current unmanned plane
The first average path loss being subject to, η1For what is formed in the mobile terminal by the aerial current unmanned plane and ground
In the scene of vacant lot, what the current unmanned plane was subject to when sending signal to the mobile terminal presets the first extra path loss
Value；As i=2, PL2The the second average path damage being subject to when sending signal to the mobile terminal for the unmanned plane to be selected
Consumption；η2It is described to be selected in the vacant lot scene that the mobile terminal by the aerial unmanned plane to be selected and ground is formed
The default second extra path loss value that unmanned plane is subject to when sending signal to the mobile terminal；
It is calculated separately using following formula according to first average path loss and second average path loss
When the mobile terminal is located at each expected trajectory point, the current unmanned aerial vehicle onboard base station of the mobile terminal reporting
The first expected RSRP and the mobile terminal reporting the unmanned aerial vehicle onboard base station to be selected the second expected RSRP；
RSRPi=P-PLi
In formula, i=1,2；As i=1, RSRP1For the current unmanned aerial vehicle onboard of the mobile terminal reporting
The expected RSRP of the first of base station；As i=2, RSRP2For the unmanned aerial vehicle onboard base station to be selected of the mobile terminal reporting
Second expected RSRP；P is the transmission power of the current unmanned aerial vehicle onboard base station and the unmanned aerial vehicle onboard base station to be selected.
The invention also provides a kind of switching device of unmanned aerial vehicle onboard base station based on user trajectory prediction, described devices
It include: trigger condition judgement unit, trajectory predictions unit, switch decision unit and switching execution unit；
Whether the trigger condition judgement unit detects mobile terminal for the switch decision standard based on mobile communication
Come into the overlapping covered of current service cell and serving cell to be selected, wherein the current unmanned aerial vehicle onboard base station
Under current service cell and unmanned aerial vehicle onboard base station to be selected under serving cell to be selected be neighboring community, the mobile terminal works as
Before belong to the current service cell；
The trajectory predictions unit, if the testing result for user's critical localisation detection unit is described first
RSRP and the 2nd RSRP meets the switch decision standard of mobile communication, then the mobile terminal is reached the present bit
The historical track point of default first quantity before setting and the tracing point of the current location, are determined as the prediction trained in advance
The input set of model；Using the prediction model, it is default after reaching the current location to calculate the mobile terminal
The expected trajectory point of second quantity, wherein the prediction model is based on the regression prediction method in machine learning, for according to shifting
Dynamic terminal enter it is described it is overlapping covered before historical track point and current location tracing point, calculate mobile terminal and exist
Into it is described it is overlapping covered after expected trajectory point；
The switch decision unit is located at calculated of the trajectory predictions unit when the mobile terminal for judging
When the 1 expected trajectory point, whether the expected trajectory point corresponding default first expected RSRP and default second expected RSRP is full
The switch decision standard of the foot mobile communication, wherein the described first expected RSRP refers to when to be located at this pre- for the mobile terminal
When phase tracing point, pass through the current unmanned aerial vehicle onboard base station of the calculated mobile terminal reporting of preset derivation formula
Expection RSRP, the described second expected RSRP refers to when the mobile terminal is located at the expected trajectory point, is preset by described
The calculated mobile terminal reporting of derivation formula the unmanned aerial vehicle onboard base station to be selected expection RSRP；
The switching execution unit, if the judging result for the second judgment unit be the described first expected RSRP and
The second expected RSRP meets the switch decision standard of the mobile communication, then by the mobile terminal from the current service
Cell switches to the serving cell to be selected.
Preferably, the prediction model is by executing as lower unit is default:
Acquiring unit, the corresponding track point set of mobile terminal for obtaining default third quantity, wherein the track
Point set include each mobile terminal enter it is described it is overlapping covered before tracing point and each mobile terminal into
Enter it is described it is overlapping covered after tracing point；
Training unit, for the track point set to be inputted initial predicted model, training obtains the prediction model.
Preferably, default second quantity is determined by executing lower unit such as:
The trajectory predictions unit is also used for following formula and calculates default second quantity；
In formula, k is default second quantity；TTT is preset triggering duration；△ T is default first number
Time interval between the historical track point of amount；Ceil function, which is used to return, is more than or equal to the minimum whole of specified expression formula
Number.
Preferably, the trajectory predictions unit, is also used for following formula, calculates separately when the mobile terminal is located at
When each expected trajectory point, project to the mobile terminal of the current unmanned plane in horizontal plane where the mobile terminal
The second distance for projecting to the mobile terminal of one distance and unmanned plane to be selected in horizontal plane where the mobile terminal；
In formula, i=1,2；As i=1, d1It is the current unmanned plane in horizontal plane where the mobile terminal
Project to the first distance of the mobile terminal, (x1, y1) it is the current unmanned plane in horizontal plane where the mobile terminal
Projected position coordinate；As i=2, d2It is described in projecting to for horizontal plane where the mobile terminal for the unmanned plane to be selected
The second distance of mobile terminal, (x2, y2) it is that the unmanned plane to be selected is sat in the projected position of horizontal plane where the mobile terminal
Mark；(xc, yc) it is any desired guiding trajectory point coordinate；
The trajectory predictions unit, is also used for following formula, according to the first distance and the second distance, divides
Ji Suan not be when the mobile terminal be located at each expected trajectory point, the current unmanned plane to the first of the mobile terminal
The second straight line distance of linear distance and the unmanned plane to be selected to the mobile terminal；
In formula, i=1,2；As i=1, s1For the current unmanned plane to the mobile terminal first straight line away from
From h1For the vertical range of horizontal plane where the current unmanned plane to the mobile terminal；As i=2, s2It is described to be selected
Second straight line distance of the unmanned plane to the mobile terminal, h2For horizontal plane where the unmanned plane to be selected to the mobile terminal
Vertical range；
The trajectory predictions unit, is also used for following formula, directly according to the first straight line distance and described second
Linear distance is calculated separately when the mobile terminal is located at each expected trajectory point, and the first of the current unmanned plane is freely
The path loss of second free space of the path loss in space and the unmanned plane to be selected；
FSPLi=20log log (si)+20log log(fMHZ)-27.55
In formula, i=1,2；As i=1, FSPL1For the path damage of the first free space of the current unmanned plane
Consumption；As i=2, FSPL2For the path loss of the second free space of the unmanned plane to be selected；fMHZFor the current unmanned plane
The transmitting frequency range of airborne base station and the unmanned aerial vehicle onboard base station to be selected；
The trajectory predictions unit, is also used for following formula, according to the path loss of first free space and
The path loss of second free space is calculated separately when the mobile terminal is located at each expected trajectory point, described
The first average path loss that current unmanned plane is subject to when sending from signal to the mobile terminal and the unmanned plane to be selected to
The mobile terminal sends the second average path loss being subject to when signal；
PLi=FSPLi+ηi
In formula, i=1,2；As i=1, PL1When sending signal to the mobile terminal for the current unmanned plane
The first average path loss being subject to, η1For what is formed in the mobile terminal by the aerial current unmanned plane and ground
In the scene of vacant lot, what the current unmanned plane was subject to when sending signal to the mobile terminal presets the first extra path loss
Value；As i=2, PL2The the second average path damage being subject to when sending signal to the mobile terminal for the unmanned plane to be selected
Consumption；η2It is described to be selected in the vacant lot scene that the mobile terminal by the aerial unmanned plane to be selected and ground is formed
The default second extra path loss value that unmanned plane is subject to when sending signal to the mobile terminal；
The trajectory predictions unit, is also used for following formula, according to first average path loss and described
Two average path loss are calculated separately when the mobile terminal is located at each expected trajectory point, the mobile terminal reporting
The current unmanned aerial vehicle onboard base station the first expected RSRP and the mobile terminal reporting the unmanned plane machine to be selected
Carry the second expected RSRP of base station；
RSRPi=P-PLi
In formula, i=1,2；As i=1, RSRP1For the current unmanned aerial vehicle onboard of the mobile terminal reporting
The expected RSRP of the first of base station；As i=2, RSRP2For the unmanned aerial vehicle onboard base station to be selected of the mobile terminal reporting
Second expected RSRP；P is the transmission power of the current unmanned aerial vehicle onboard base station and the unmanned aerial vehicle onboard base station to be selected.
The switching method and apparatus of unmanned aerial vehicle onboard base station provided by the invention based on user trajectory prediction, firstly, base
In the switch decision standard of mobile communication, detect whether mobile terminal comes into current service cell and serving cell to be selected
It is overlapping covered, wherein under the current service cell and unmanned aerial vehicle onboard base station to be selected under current unmanned aerial vehicle onboard base station
Serving cell to be selected is neighboring community, and mobile terminal current home is in the current service cell；If it has, then according to mobile whole
The historical track point of default first quantity of the end before reaching current location, it is pre- after current location to calculate mobile terminal
If the expected trajectory point of the second quantity；Next, it is judged that when mobile terminal is located at any expected trajectory point, the expected trajectory point
Whether corresponding default first expected RSRP and default second expected RSRP meets the switch decision standard of mobile communication, wherein
First expected RSRP refer to the mobile terminal reporting predicted when the mobile terminal is located at expected trajectory point it is current nobody
The expection RSRP, the second expected RSRP of the airborne base station of machine refer to that when the mobile terminal is located at expected trajectory point, what is predicted should
The expection RSRP of the unmanned aerial vehicle onboard base station to be selected of mobile terminal reporting；If it has, then by mobile terminal from current service cell
Switch to serving cell to be selected.
In this way, working as mobile terminal by judgement in the case where mobile terminal meets the switch decision standard of mobile communication
Whether meet the switch decision standard of mobile communication when positioned at calculated expected trajectory point and quickly decides whether to need to realize
Cell switching is carried out to mobile terminal, guarantees the communication quality of user.Certainly, it implements any of the products of the present invention or method must not
It is certain to need while reaching all the above advantage.
Detailed description of the invention
It, below will be to embodiment or the prior art in order to illustrate more clearly of the present invention or technical solution in the prior art
Attached drawing needed in description is briefly described, it should be apparent that, the accompanying drawings in the following description is only of the invention
Some embodiments for those of ordinary skill in the art without creative efforts, can also be according to this
A little attached drawings obtain other attached drawings.
Fig. 1 is the flow chart of the switching method of the unmanned aerial vehicle onboard base station of the invention based on user trajectory prediction；
Fig. 2 is application scenarios schematic diagram of the invention；
Fig. 3 is the schematic diagram of the switching device of the unmanned aerial vehicle onboard base station of the invention based on user trajectory prediction.
Specific embodiment
Below in conjunction with the attached drawing in the present invention, the technical solution in the present invention is clearly and completely described, is shown
So, described embodiments are only a part of the embodiments of the present invention, instead of all the embodiments.Based on the reality in the present invention
Example is applied, every other embodiment obtained by those of ordinary skill in the art without making creative efforts all belongs to
In the scope of protection of the invention.
With the fast development of mechanics of communication, using unmanned aerial vehicle onboard base station solve hot spot region covering and access by
More and more concerns are communicated currently, having been realized in using unmanned aerial vehicle onboard base station as aerial access point.In reality
In, there are overlapping covered for the coverage area of two neighboring serving cell.In order to guarantee the communication quality of user and make
With experience, when mobile terminal be moved to two serving cells it is overlapping covered when, need to judge whether to mobile terminal into
The switching of row cell.
Specifically, sentencing in Long Term Evolution (Long Term Evolution, mobile communication) network in known technology
The disconnected detailed process that cell switching whether is carried out to mobile terminal are as follows:
Step 1: judging that mobile terminal corresponds to the RSRP of the base station to be selected corresponding with the mobile terminal RSRP of current base station and is
The no switch decision standard for meeting mobile communication, wherein shown in the switch decision standard such as formula (1) of mobile communication:
RSRP2≥RSRP1+HOM (1)
In formula (1), RSRP2 is the RSRP that the mobile terminal corresponds to base station to be selected；RSRP1 is corresponding for the mobile terminal
The RSRP of current base station；HOM is that preset switching lags difference, can be specifically arranged according to the actual situation.
Step 2: if it has, then, current base station interior in triggering duration (Time Triggered Technology, TTT)
According to predetermined period, repeatedly receives the mobile terminal and correspond to the RSRP of current base station and correspond to base station to be selected with the mobile terminal
RSRP；Judge the mobile terminal correspond to current base station RSRP and the RSRP that the mobile terminal corresponds to base station to be selected whether continue it is full
The switch decision standard of sufficient mobile communication.
Step 3: if it has, then the mobile terminal is switched to base station to be selected from the current service cell under current base station
Under serving cell to be selected.
Wherein, above-mentioned current service cell and serving cell to be selected are the neighboring community for belonging to different base station, current to take
There is the region of overlapping covering in cell of being engaged in and serving cell to be selected, current mobile terminal belongs to current service cell.
As it can be seen that current base station needs persistently receive mobile terminal reporting in TTT in above-mentioned cell switching flow
RSRP simultaneously makes decisions, in this way, extending the duration for waiting cell switching, in fact it could happen that led due to not timely switching cell
The problem of causing conversation loss or poor communications quality.Therefore, the invention proposes the unmanned plane machines predicted based on user trajectory
The switching method for carrying base station can be decided whether quickly to need to carry out cell switching to mobile terminal, guarantee the communication matter of user
Amount.
The invention discloses a kind of switching methods of unmanned aerial vehicle onboard base station based on user trajectory prediction.Referring to Fig. 1, figure
1 is the flow chart of the switching method of the unmanned aerial vehicle onboard base station of the invention based on user trajectory prediction, is included the following steps:
Step 101, the switch decision standard based on mobile communication, it is small whether detection mobile terminal comes into current service
Area and serving cell to be selected it is overlapping covered；If so, executing step 102.
Wherein, under the current service cell and unmanned aerial vehicle onboard base station to be selected under the current unmanned aerial vehicle onboard base station to
Selecting serving cell is neighboring community, and the mobile terminal current home is in the current service cell.
In this step, when mobile terminal is moved to the overlapping covered of current service cell and serving cell to be selected
When, the first Reference Signal Received Power RSRP and the movement for detecting the current unmanned aerial vehicle onboard base station of the mobile terminal reporting are whole
Hold whether the 2nd RSRP of the unmanned aerial vehicle onboard base station to be selected reported meets the switch decision standard of mobile communication, wherein mobile
The switch decision standard of communication can be with reference formula (1).
It should be noted that the detailed process of this step can refer to the prior art, details are not described herein.
Step 102, the historical track point of default first quantity by mobile terminal before reaching current location and work as
The tracing point of front position is determined as the input set for the prediction model trained in advance.
In this step, as the first RSRP and the mobile terminal of the current unmanned aerial vehicle onboard base station of the mobile terminal reporting
When 2nd RSRP of the unmanned aerial vehicle onboard base station to be selected reported meets the switch decision standard of mobile communication, which is existed
The historical track point of default first quantity before reaching current location and the tracing point of current location, are determined as preparatory training
Prediction model input set.
In practical applications, the historical track point of default first quantity before mobile terminal reaches current location and
In the tracing point of current location, the time interval between adjacent two o'clock is △ T；Wherein, presetting the first quantity can be according to reality
Border situation determines.
Step 103, using prediction model, default second quantity of the mobile terminal after reaching the current location is calculated
Expected trajectory point, wherein prediction model is based on the regression prediction method in machine learning, for being entered according to mobile terminal
It is overlapping covered in entrance to calculate mobile terminal for the tracing point of historical track point and current location before overlapping covered
Expected trajectory point later.
Specifically, preset model can according to mobile terminal enter it is overlapping covered before historical track point and work as
The tracing point of front position calculates expected trajectory point of the mobile terminal after entrance is overlapping covered, that is to say, that default
Model can calculate mobile terminal after entrance is overlapping covered by using the regression prediction method in machine learning
Expected trajectory point.
Wherein, prediction model can be neural network, be also possible to be returned by Gaussian Mixture clustering method and Gaussian process
The mixed model of method composition, it is of course also possible to be the mathematical model that other are able to use regression prediction method.It specifically can root
The prediction model used is determined according to actual conditions, the present invention is without restriction to this.
It should be understood that it is exactly the motion track for predicting mobile terminal, root that the expected trajectory point of default second quantity is practical
It is predicted that the motion track gone out, can quickly decide whether to need to switch to mobile terminal into serving cell to be selected.Compared to existing
Technology can just decide whether to need to switch over without waiting for TTT, the to be switched duration such as shorten, improve switching efficiency,
Guarantee the communication quality of user.
Step 104, judge that the expected trajectory point is corresponding when the mobile terminal is located at any expected trajectory point
Whether default first expected RSRP and default second expected RSRP meets the switch decision standard of the mobile communication, if so,
Execute step 105.
Wherein, the described first expected RSRP refers to when the mobile terminal is located at the expected trajectory point, by preset
The expection RSRP of the current unmanned aerial vehicle onboard base station of the calculated mobile terminal reporting of derivation formula, described second is pre-
Phase RSRP refers to when the mobile terminal is located at the expected trajectory point, passes through the calculated movement of preset derivation formula
The expection RSRP for the unmanned aerial vehicle onboard base station to be selected that terminal reports.
In this step, the expected trajectory point for calculating default second quantity of the mobile terminal after current location it
Afterwards, judge when the mobile terminal is located at any expected trajectory point, the corresponding first expected RSRP and second of the expected trajectory point
It is expected that whether RSRP meets the switch decision standard of mobile communication, so as to quickly decide whether to need to switch to mobile terminal to
Select serving cell；Wherein, the first expected RSRP and the second expected RSRP can be according to the expected trajectory point meters of mobile terminal
It obtains.
Step 105, the mobile terminal is switched into the serving cell to be selected from the current service cell.
In this step, when mobile terminal is located at any expected trajectory point, the expected trajectory point corresponding default first
It is expected that when RSRP and default second expected RSRP are all satisfied the switch decision standard of mobile communication, by mobile terminal from current service
Cell switches to serving cell to be selected.This way it is not necessary to wait TTT, persistently reported without to current unmanned aerial vehicle onboard base station
First RSRP and the 2nd RSRP, it will be able to quickly determine the need for switching over mobile terminal, improve switching efficiency.
As it can be seen that the switching method of the unmanned aerial vehicle onboard base station provided by the invention based on user trajectory prediction, it can be when shifting
The current location of dynamic terminal be located at current service cell and serving cell to be selected it is overlapping covered when, and mobile terminal satisfaction
In the case where the switch decision standard of mobile communication, by detecting when mobile terminal is located at calculated any expected trajectory point
Whether meet the switch decision standard of mobile communication, quickly decide whether to need to carry out cell switching to mobile terminal to realize,
Guarantee the communication quality of user.
In an alternative embodiment of the invention, to it is shown in FIG. 1 it is of the invention based on user trajectory prediction nobody
Step 102 to step 104 in the switching method of the airborne base station of machine is described in detail:
It should be noted that default second quantity of expected trajectory point can determine have according to △ T and preset TTT
Body, it can be calculated by formula (2):
In formula (2), k is default second quantity；TTT is preset triggering duration；△ T is default first quantity
Historical track point between time interval；Ceil function is used to return to the smallest positive integral for being more than or equal to specified expression formula.
Assuming that current time is t0, the tracing point coordinate of mobile terminal current location is (xt0, yt0), it is contemplated that tracing point it is pre-
If the second quantity is k；Calculating expected trajectory point, specific step is as follows:
The first step determines first input set T of prediction model0, comprising: mobile terminal is before reaching current location
Default first quantity historical track point coordinate (xT1, yT1)、(xT2, yT2) ... and the tracing point coordinate of current location
(xt0, yt0), as shown in formula (3)；
T0={ (xT1,yT1), (xT2,yT2),…,(xt0,yt0)} (3)
Second step will input set T0It is input in prediction model, calculates subsequent time t1Expected trajectory point coordinate
(xt1, yt1), wherein t1=t0+△T。
Third step, judgement are located at expected trajectory point coordinate (x when mobile terminalt1, yt1) when, corresponding default first is expected
Whether RSRP and default second expected RSRP meets the switch decision standard of mobile communication；If it has, then expected trajectory point is sat
Mark (xt1, yt1) it is added to input set T0In, obtain second input set T1, comprising: mobile terminal reaches current location
The historical track point coordinate (x of default first quantity beforeT1, yT1)、(xT2, yT2) ..., the tracing point coordinate of current location
(xt0, yt0) and moment t1Expected trajectory point coordinate (xt1, yt1), as shown in formula (4):
T1={ (xT1,yT1), (xT2,yT2),…,(xt0,yt0),(xt1,yt1)} (4)
4th step will input set T1It is input in prediction model, calculates subsequent time t2Expected trajectory point coordinate
(xt2, yt2), wherein t2=t0+△T+△T。
5th step, judgement are located at expected trajectory point coordinate (x when mobile terminalt2, yt2) when, corresponding default first is expected
Whether RSRP and default second expected RSRP meets the switch decision standard of mobile communication；If it has, then expected trajectory point is sat
Mark (xt2, yt2) it is added to input set T0In, obtain third input set T2, so recycle.
If one of expected trajectory point corresponding default first expected RSRP and default second expected RSRP is unsatisfactory for moving
The switch decision standard of dynamic communication, then stop switching flow, does not carry out cell switching to mobile terminal；If it is determined that k expected rail
Mark point corresponding default first expected RSRP and default second expected RSRP are all satisfied the switch decision standard of mobile communication, then after
It is continuous to execute step 205.
It should be understood that it is exactly the moving rail for predicting mobile terminal in TTT that calculated k a expected trajectory point is practical
Mark just quickly decides whether to need to switch to mobile terminal into serving cell to be selected according to the motion track predicted；Compared to existing
There is technology, can just decide whether to need to switch over without waiting for TTT, the to be switched duration such as shorten, improve switching effect
Rate guarantees the communication quality of user.
In practical applications, the unmanned aerial vehicle onboard base station of the invention based on user trajectory prediction shown in FIG. 1 is being executed
Switching method in step 102 before, need to train preset model.The training process of the prediction model includes:
Obtain the corresponding track point set of mobile terminal of default third quantity, wherein the track point set includes each
Mobile terminal enter it is described it is overlapping covered before tracing point and each mobile terminal enter it is described overlapping cover
Tracing point after cover area；
The track point set is inputted into initial predicted model, training obtains the prediction model.
Specifically, may include the mobile terminal of default third quantity for training the track point set of prediction model
Track point data；For example, when default third quantity is 1000, then, track point set includes every in 1000 mobile terminals
A mobile terminal enter it is overlapping covered before 20 groups of tracing points and it is overlapping covered after 5 groups of tracing points.
Certainly, presetting third quantity and the group number of tracing point can be arranged according to the actual situation.
In this way, the tracing point of historical track point and current location by mobile terminal before entrance is overlapping covered is defeated
Enter into trained prediction model, can output mobile terminal enter it is overlapping covered after expected trajectory point, with
Just it quickly decides whether to need to switch to mobile terminal into serving cell to be selected according to expected trajectory point.
In an alternative embodiment of the invention, corresponding to expected trajectory point in step 103 default first is expected
The calculation method of RSRP and default second expected RSRP are described in detail.Specifically, the process may include steps of:
Step 1 is calculated separately when the mobile terminal is located at each expected trajectory point, currently using formula (5)
Unmanned plane exists in the first distance for projecting to the mobile terminal of horizontal plane where the mobile terminal and unmanned plane to be selected
The second distance for projecting to the mobile terminal of horizontal plane where the mobile terminal；
In formula (5), i=1,2；As i=1, d1It is horizontal where the mobile terminal for the current unmanned plane
The first distance for projecting to the mobile terminal in face, (x1, y1) it is that the current unmanned plane is horizontal where the mobile terminal
The projected position coordinate in face；As i=2, d2For the unmanned plane to be selected projecting in horizontal plane where the mobile terminal
The second distance of the mobile terminal, (x2, y2) it is the unmanned plane to be selected in the projection position of horizontal plane where the mobile terminal
Set coordinate；(xc, yc) it is any desired guiding trajectory point coordinate.
Specifically, according to desired guiding trajectory point coordinate (xc, yc), and current unmanned plane and unmanned plane to be selected are in mobile terminal
Projection (the x of place horizontal plane1, y1) and (x2, y2), the throwing of current unmanned plane horizontal plane where mobile terminal can be calculated
First distance d of the shadow to mobile terminal1The horizontal plane where mobile terminal projects to the mobile terminal with unmanned plane to be selected
Second distance d2。
With reference to Fig. 2, Fig. 2 is application scenarios schematic diagram of the invention.As shown in Fig. 2, where point B in Fig. 2 by slash
The dash area of composition is the overlapping covered of current service cell and serving cell to be selected, it is believed that point B is movement
The current location of terminal.Point A is historical track point of the mobile terminal before reaching current location point B, the expection of mobile terminal
Tracing point is point C.
As shown in Fig. 2, being illustrated so that expected trajectory point is point C as an example in Fig. 2, point C coordinate is (xc, yc), point C is to working as
Subpoint position coordinates (x of the preceding unmanned plane in horizontal plane where point C1, y1) first distance be d1, point C to unmanned plane to be selected exists
Projected position coordinate (the x of horizontal plane where point C2, y2) second distance be d2。
Step 2 according to the first distance and the second distance, is calculated separately when the movement using formula (6)
When terminal is located at each expected trajectory point, the first straight line distance of the current unmanned plane to the mobile terminal, Yi Jisuo
State unmanned plane to be selected to the mobile terminal second straight line distance；
In formula (6), i=1,2；As i=1, s1First for the current unmanned plane to the mobile terminal is straight
Linear distance, h1For the vertical range of horizontal plane where the current unmanned plane to the mobile terminal；As i=2, s2It is described
Second straight line distance of the unmanned plane to be selected to the mobile terminal, h2For water where the unmanned plane to be selected to the mobile terminal
The vertical range of plane.
Specifically, according to the first distance d for projecting to mobile terminal of current unmanned plane horizontal plane where mobile terminal1
With the second distance d for projecting to the mobile terminal of unmanned plane to be selected horizontal plane where mobile terminal2, and it is current nobody
Vertical range h of the machine to horizontal plane where mobile terminal1With the vertical range of horizontal plane where unmanned plane to be selected to mobile terminal
h2, can calculate current unmanned plane to mobile terminal first straight line distance s1With the second of unmanned plane to be selected to mobile terminal
Linear distance s2。
As shown in Fig. 2, the first straight line distance of current unmanned plane to point C are s1, the second straight line of unmanned plane to be selected to point C
Distance is s2, h1For the vertical range of horizontal plane where current unmanned plane to point C, h2For horizontal plane where unmanned plane to be selected to point C
Vertical range.
Step 3 is calculated separately and is worked as according to the first straight line distance and the second straight line distance using formula (7)
When the mobile terminal is located at each expected trajectory point, the path loss of the first free space of the current unmanned plane, with
And the path loss of the second free space of the unmanned plane to be selected；
FSPLi=20log log (si)+20log log(fMHZ)-27.55 (7)
In formula (7), i=1,2；As i=1, FSPL1For the path of the first free space of the current unmanned plane
Loss；As i=2, FSPL2For the path loss of the second free space of the unmanned plane to be selected；fMHZFor it is described it is current nobody
The transmitting frequency range of the airborne base station of machine and the unmanned aerial vehicle onboard base station to be selected.
Specifically, according to calculated first straight line distance s1With second straight line distance s2And known transmitting frequency range
fMHZ, the path loss FSPL of the first free space of current unmanned plane can be calculated1It is freely empty with the second of unmanned plane to be selected
Between path loss FSPL2。
Step 4, using formula (8), according to the path loss of first free space and second free space
Path loss is calculated separately when the mobile terminal is located at each expected trajectory point, and the current unmanned plane is to the shifting
Dynamic terminal, which sends the first average path loss being subject to when signal and the unmanned plane to be selected and sends to the mobile terminal, to be believed
Number when the second average path loss for being subject to；
PLi=FSPLi+ηi (8)
In formula (8), i=1,2；As i=1, PL1Signal is sent to the mobile terminal for the current unmanned plane
When the first average path loss for being subject to, η1To be formed in the mobile terminal by the aerial current unmanned plane and ground
Vacant lot scene in, default first extra path loss that the current unmanned plane is subject to when sending from signal to the mobile terminal
Value；As i=2, PL2The the second average path damage being subject to when sending signal to the mobile terminal for the unmanned plane to be selected
Consumption；η2It is described to be selected in the vacant lot scene that the mobile terminal by the aerial unmanned plane to be selected and ground is formed
The default second extra path loss value that unmanned plane is subject to when sending signal to the mobile terminal.
It should be noted that when unmanned plane is in different flying heights, when unmanned plane sends signal to mobile terminal by
To extra path loss value be different.In practical applications, can in the case where unmanned plane is in different flying heights,
The extra path loss value that measurement multiple groups unmanned plane is subject to when sending signal to mobile terminal, and multiple groups measured value is counted
Unmanned plane is obtained after processing is in corresponding extra path loss value when different flying heights.It should be understood that default first volume
Outer pathway loss value η1It is to be determined according to the flying height of current unmanned plane, presets the second extra path loss value η2It is basis
What the flying height of unmanned plane to be selected determined；When current unmanned plane is identical with the flying height of unmanned plane to be selected, first is preset
Extra path loss value η1With default second extra path loss value η2It is identical.
Specifically, according to the path loss FSPL of the first free space of calculated current unmanned plane1With it is to be selected nobody
The path loss FSPL of second free space of machine2And known excess loss η, current unmanned plane can be calculated to movement
Terminal sends the first average path loss PL being subject to when signal1It is subject to when sending signal to mobile terminal with unmanned plane to be selected
Second average path loss PL2。
Step 5 is divided using formula (9) according to first average path loss and second average path loss
Ji Suan not be when the mobile terminal be located at each expected trajectory point, the current unmanned plane machine of the mobile terminal reporting
Carry the first expected RSRP of base station and the unmanned aerial vehicle onboard base station to be selected of the mobile terminal reporting second is expected
RSRP；
RSRPi=P-PLi (9)
In formula (9), i=1,2；As i=1, RSRP1For the current unmanned plane machine of the mobile terminal reporting
Carry the first expected RSRP of base station；As i=2, RSRP2For the unmanned aerial vehicle onboard base station to be selected of the mobile terminal reporting
The second expected RSRP；P is the transmission power of the current unmanned aerial vehicle onboard base station and the unmanned aerial vehicle onboard base station to be selected.
The first average path being subject to when specifically, sending signal to mobile terminal according to calculated current unmanned plane damages
Consume PL1The second average path loss PL being subject to when sending signal to mobile terminal with unmanned plane to be selected2And it is known nobody
The transmission power of the airborne base station of machine, when can calculate mobile terminal and being located at expected trajectory point, the current unmanned aerial vehicle onboard that reports
The second expected RSRP of the expected RSRP of the first of base station and unmanned aerial vehicle onboard base station to be selected.
By formula (5) to formula (9) it is found that because the transmission power P of unmanned aerial vehicle onboard base station is identical, the transmitting used is frequently
Section fMHZAlso identical, and the vertical range of unmanned plane to horizontal plane where mobile terminal is constant, so, signal is in transmission process
Suffered free space path loss FSPL is only and unmanned plane is related with the linear distance s of mobile terminal, simultaneously as surrounding
Excess loss η caused by environment is constant, it is known that the average path loss PL that unmanned plane is subject to when sending signal to mobile terminal
Also only related with linear distance s.
In conclusion when mobile terminal is located at any expected trajectory point, it is contemplated that tracing point corresponding default first is expected
The RSRP only first straight line distance s with current unmanned plane and mobile terminal1It is related, preset the second expected RSRP only with it is to be selected nobody
The second straight line distance s of machine and mobile terminal2It is related.
As it can be seen that the switching method of the unmanned aerial vehicle onboard base station provided by the invention based on user trajectory prediction, can move
In the case that dynamic terminal meets the switch decision standard of mobile communication, by judging that the calculated first expected RSRP and second is pre-
Whether phase RSRP meets the switch decision standard of mobile communication, quickly decides whether to need to carry out cell to mobile terminal to realize
Switching；It should be noted that due to the first expected RSRP only first straight line distance s with current unmanned plane and mobile terminal1Have
It closes, presets the second expected RSRP only second straight line distance s with unmanned plane to be selected and mobile terminal2It is related, it therefore, can basis
The first straight line distance s of current unmanned plane and mobile terminal1With the second straight line distance s of unmanned plane to be selected and mobile terminal2, quasi-
The expected RSRP of the first expected RSRP and second is really calculated, enables to accurately rule out and whether needs to carry out mobile terminal
Cell switching, guarantees the communication quality of user.
The invention also discloses a kind of switching devices of unmanned aerial vehicle onboard base station based on user trajectory prediction.Referring to Fig. 3,
Fig. 3 is the schematic diagram of the switching device of the unmanned aerial vehicle onboard base station of the invention based on user trajectory prediction, and described device includes:
Trigger condition judgement unit 301, trajectory predictions unit 302, switch decision unit 303 and switching execution unit 304；
The trigger condition judgement unit 301, for the switch decision standard based on mobile communication, detecting mobile terminal is
It is no to come into the overlapping covered of current service cell and serving cell to be selected, wherein the current unmanned aerial vehicle onboard base
The serving cell to be selected under current service cell and unmanned aerial vehicle onboard base station to be selected under standing is neighboring community, the mobile terminal
Current home is in the current service cell；
The trajectory predictions unit 302, for by the mobile terminal before reaching the current location default the
The historical track point of one quantity and the tracing point of the current location, are determined as the input set of prediction model trained in advance
It closes；Using the prediction model, the pre- of default second quantity of the mobile terminal after reaching the current location is calculated
Phase tracing point, wherein the prediction model is based on the regression prediction method in machine learning, for being entered according to mobile terminal
It is described it is overlapping covered before historical track point and current location tracing point, calculate mobile terminal enter the overlapping
Expected trajectory point after overlay area；
The switch decision unit 303 is calculated for judging when the mobile terminal is located at the trajectory predictions unit
Any expected trajectory point when, the expected trajectory point corresponding default first expected RSRP and default second expected RSRP are
The no switch decision standard for meeting the mobile communication, wherein the described first expected RSRP refers to when the mobile terminal is located at
When the expected trajectory point, pass through the current unmanned aerial vehicle onboard of the calculated mobile terminal reporting of preset derivation formula
The expection RSRP of base station, described second, which is expected RSRP, refers to when the mobile terminal is located at the expected trajectory point, by described
The expection RSRP of the unmanned aerial vehicle onboard base station to be selected of the preset calculated mobile terminal reporting of derivation formula；
The switching execution unit 304, if the judging result for the second judgment unit is described first expected
The RSRP and second expected RSRP meets the switch decision standard of the mobile communication, then works as the mobile terminal from described
Preceding serving cell switches to the serving cell to be selected.
In one preferred embodiment of the invention, the prediction model is by executing as lower unit is default:
Acquiring unit, the corresponding track point set of mobile terminal for obtaining default third quantity, wherein the track
Point set include each mobile terminal enter it is described it is overlapping covered before tracing point and each mobile terminal into
Enter it is described it is overlapping covered after tracing point；
Training unit, for the track point set to be inputted initial predicted model, training obtains the prediction model.
In another preferred embodiment of the invention, default second quantity is determined by executing lower unit such as:
The trajectory predictions unit is also used for following formula and calculates default second quantity；
In formula, k is default second quantity；TTT is preset triggering duration；△ T is default first number
Time interval between the historical track point of amount；Ceil function, which is used to return, is more than or equal to the minimum whole of specified expression formula
Number.
In another preferred embodiment of the invention,
The trajectory predictions unit, is also used for following formula, calculates separately when the mobile terminal is positioned at each described
When expected trajectory point, current unmanned plane horizontal plane where the mobile terminal project to the first of the mobile terminal away from
From and unmanned plane to be selected horizontal plane where the mobile terminal the second distance for projecting to the mobile terminal；
In formula, i=1,2；As i=1, d1It is the current unmanned plane in horizontal plane where the mobile terminal
Project to the first distance of the mobile terminal, (x1, y1) it is the current unmanned plane in horizontal plane where the mobile terminal
Projected position coordinate；As i=2, d2It is described in projecting to for horizontal plane where the mobile terminal for the unmanned plane to be selected
The second distance of mobile terminal, (x2, y2) it is that the unmanned plane to be selected is sat in the projected position of horizontal plane where the mobile terminal
Mark；(xc, yc) it is any desired guiding trajectory point coordinate；
The trajectory predictions unit, is also used for following formula, according to the first distance and the second distance, divides
Ji Suan not be when the mobile terminal be located at each expected trajectory point, the current unmanned plane to the first of the mobile terminal
The second straight line distance of linear distance and the unmanned plane to be selected to the mobile terminal；
In formula, i=1,2；As i=1, s1For the current unmanned plane to the mobile terminal first straight line away from
From h1For the vertical range of horizontal plane where the current unmanned plane to the mobile terminal；As i=2, s2It is described to be selected
Second straight line distance of the unmanned plane to the mobile terminal, h2For horizontal plane where the unmanned plane to be selected to the mobile terminal
Vertical range；
The trajectory predictions unit, is also used for following formula, directly according to the first straight line distance and described second
Linear distance is calculated separately when the mobile terminal is located at each expected trajectory point, and the first of the current unmanned plane is freely
The path loss of second free space of the path loss in space and the unmanned plane to be selected；
FSPLi=20log log (si)+20log log(fMHZ)-27.55
In formula, i=1,2；As i=1, FSPL1For the path damage of the first free space of the current unmanned plane
Consumption；As i=2, FSPL2For the path loss of the second free space of the unmanned plane to be selected；fMHZFor the current unmanned plane
The transmitting frequency range of airborne base station and the unmanned aerial vehicle onboard base station to be selected；
The trajectory predictions unit, is also used for following formula, according to the path loss of first free space and
The path loss of second free space is calculated separately when the mobile terminal is located at each expected trajectory point, described
The first average path loss that current unmanned plane is subject to when sending from signal to the mobile terminal and the unmanned plane to be selected to
The mobile terminal sends the second average path loss being subject to when signal；
PLi=FSPLi+ηi
In formula, i=1,2；As i=1, PL1When sending signal to the mobile terminal for the current unmanned plane
The first average path loss being subject to, η1For what is formed in the mobile terminal by the aerial current unmanned plane and ground
In the scene of vacant lot, what the current unmanned plane was subject to when sending signal to the mobile terminal presets the first extra path loss
Value；As i=2, PL2The the second average path damage being subject to when sending signal to the mobile terminal for the unmanned plane to be selected
Consumption；η2It is described to be selected in the vacant lot scene that the mobile terminal by the aerial unmanned plane to be selected and ground is formed
The default second extra path loss value that unmanned plane is subject to when sending signal to the mobile terminal；
The trajectory predictions unit, is also used for following formula, according to first average path loss and described
Two average path loss are calculated separately when the mobile terminal is located at each expected trajectory point, the mobile terminal reporting
The current unmanned aerial vehicle onboard base station the first expected RSRP and the mobile terminal reporting the unmanned plane machine to be selected
Carry the second expected RSRP of base station；
RSRPi=P-PLi
In formula, i=1,2；As i=1, RSRP1For the current unmanned aerial vehicle onboard of the mobile terminal reporting
The expected RSRP of the first of base station；As i=2, RSRP2For the unmanned aerial vehicle onboard base station to be selected of the mobile terminal reporting
Second expected RSRP；P is the transmission power of the current unmanned aerial vehicle onboard base station and the unmanned aerial vehicle onboard base station to be selected.
As it can be seen that the switching device of the unmanned aerial vehicle onboard base station provided by the invention based on user trajectory prediction, it can be when shifting
The current location of dynamic terminal be located at current service cell and serving cell to be selected it is overlapping covered when, and mobile terminal satisfaction
In the case where the switch decision standard of mobile communication, the anticipated movement track of mobile terminal is calculated, and then is judged when mobile whole
Whether end meets the switch decision standard of mobile communication when being located at anticipated movement track, quickly decide whether to need to shifting to realize
Dynamic terminal carries out cell switching, guarantees the communication quality of user.
It should be noted that, in this document, relational terms such as first and second and the like are used merely to a reality
Body or operation are distinguished with another entity or operation, are deposited without necessarily requiring or implying between these entities or operation
In any actual relationship or order or sequence.Moreover, the terms "include", "comprise" or its any other variant are intended to
Non-exclusive inclusion, so that the process, method, article or equipment including a series of elements is not only wanted including those
Element, but also including other elements that are not explicitly listed, or further include for this process, method, article or equipment
Intrinsic element.In the absence of more restrictions, the element limited by sentence "including a ...", it is not excluded that
There is also other identical elements in process, method, article or equipment including the element.
Each embodiment in this specification is all made of relevant mode and describes, same and similar portion between each embodiment
Dividing may refer to each other, and each embodiment focuses on the differences from other embodiments.Especially for device reality
For applying example, since it is substantially similar to the method embodiment, so being described relatively simple, related place is referring to embodiment of the method
Part explanation.
The foregoing is merely illustrative of the preferred embodiments of the present invention, is not intended to limit the scope of the present invention.It is all
Any modification, equivalent replacement, improvement and so within the spirit and principles in the present invention, are all contained in protection scope of the present invention
It is interior.
Claims (6)
1. a kind of switching method of the unmanned aerial vehicle onboard base station based on user trajectory prediction, which is characterized in that the described method includes:
Whether the switch decision standard based on mobile communication, detection mobile terminal come into current service cell and service to be selected
Cell it is overlapping covered, wherein current service cell and unmanned aerial vehicle onboard base to be selected under current unmanned aerial vehicle onboard base station
Serving cell to be selected under standing is neighboring community, and the mobile terminal current home is in the current service cell；
If it has, then historical track point and the institute of default first quantity by the mobile terminal before reaching current location
The tracing point for stating current location is determined as the input set for the prediction model trained in advance；
Using the prediction model, the pre- of default second quantity of the mobile terminal after reaching the current location is calculated
Phase tracing point, wherein the prediction model is based on the regression prediction method in machine learning, for being entered according to mobile terminal
It is described it is overlapping covered before historical track point and current location tracing point, calculate mobile terminal enter the overlapping
Expected trajectory point after overlay area；
Judge when the mobile terminal is located at any expected trajectory point, the expected trajectory point corresponding default first is expected
Whether Reference Signal Received Power RSRP and default second expected RSRP meets the switch decision standard of the mobile communication,
In, the described first expected RSRP refers to when the mobile terminal is located at the expected trajectory point, passes through preset derivation formula meter
The expection RSRP of the current unmanned aerial vehicle onboard base station of the mobile terminal reporting calculated, described second, which is expected RSRP, refers to
When the mobile terminal is located at the expected trajectory point, by the preset calculated mobile terminal of derivation formula
The expection RSRP of the unmanned aerial vehicle onboard base station to be selected of report；
If it has, then the mobile terminal is switched to the serving cell to be selected from the current service cell；
Wherein, in the judgement when the mobile terminal is located at any expected trajectory point, the expected trajectory point is corresponding
The step of whether the default first expected RSRP and default second expected RSRP meet the switch decision standard of the mobile communication it
Before, the method also includes:
Using following formula, calculate separately when the mobile terminal is located at each expected trajectory point, current unmanned plane is in institute
The first distance for projecting to the mobile terminal of horizontal plane where stating mobile terminal and unmanned plane to be selected are described mobile whole
The second distance for projecting to the mobile terminal of horizontal plane where end；
In formula, i=1,2；As i=1, d1For the current unmanned plane horizontal plane where the mobile terminal projection
To the first distance of the mobile terminal, (x1, y1) it is projection of the current unmanned plane in horizontal plane where the mobile terminal
Position coordinates；As i=2, d2The movement is projected in horizontal plane where the mobile terminal for the unmanned plane to be selected
The second distance of terminal, (x2, y2) it is projected position coordinate of the unmanned plane to be selected in horizontal plane where the mobile terminal；
(xc, yc) it is any desired guiding trajectory point coordinate；
Using following formula, according to the first distance and the second distance, calculate separately when the mobile terminal is located at respectively
When the expected trajectory point, the first straight line distance of the current unmanned plane to the mobile terminal and it is described it is to be selected nobody
Second straight line distance of the machine to the mobile terminal；
In formula, i=1,2；As i=1, s1For the first straight line distance of the current unmanned plane to the mobile terminal, h1
For the vertical range of horizontal plane where the current unmanned plane to the mobile terminal；As i=2, s2For it is described it is to be selected nobody
Second straight line distance of the machine to the mobile terminal, h2For hanging down for horizontal plane where the unmanned plane to be selected to the mobile terminal
Straight distance；
Using following formula, according to the first straight line distance and the second straight line distance, calculate separately when described mobile whole
When end is located at each expected trajectory point, the path loss of the first free space of the current unmanned plane and described to be selected
The path loss of second free space of unmanned plane；
FSPLi=20loglog (si)+20loglog(fMHZ)-27.55
In formula, i=1,2；As i=1, FSPL1For the path loss of the first free space of the current unmanned plane；Work as i
When=2, FSPL2For the path loss of the second free space of the unmanned plane to be selected；fMHZFor the current unmanned aerial vehicle onboard base
It stands and the transmitting frequency range of the unmanned aerial vehicle onboard base station to be selected；
Using following formula, according to the path loss of the path loss of first free space and second free space,
It calculates separately when the mobile terminal is located at each expected trajectory point, the current unmanned plane is sent to the mobile terminal
What the first average path loss and the unmanned plane to be selected being subject to when signal were subject to when sending signal to the mobile terminal
Second average path loss；
PLi=FSPLi+ηi
In formula, i=1,2；As i=1, PL1The current unmanned plane is subject to when sending signal to the mobile terminal
First average path loss, η1For in the vacant lot that the mobile terminal by the aerial current unmanned plane and ground is formed
Jing Zhong, the default first extra path loss value that the current unmanned plane is subject to when sending signal to the mobile terminal；Work as i=
When 2, PL2The second average path loss being subject to when sending signal to the mobile terminal for the unmanned plane to be selected；η2For by
In the vacant lot scene that the mobile terminal of the aerial unmanned plane to be selected and ground is formed, the unmanned plane to be selected is to described
Mobile terminal sends the default second extra path loss value being subject to when signal；
It calculates separately according to first average path loss and second average path loss using following formula and works as institute
When stating mobile terminal and being located at each expected trajectory point, the of the current unmanned aerial vehicle onboard base station of the mobile terminal reporting
The expected RSRP of the second of the unmanned aerial vehicle onboard base station to be selected of one expected RSRP and the mobile terminal reporting；
RSRPi=P-PLi
In formula, i=1,2；As i=1, RSRP1For the current unmanned aerial vehicle onboard base station of the mobile terminal reporting
First expected RSRP；As i=2, RSRP2Second for the unmanned aerial vehicle onboard base station to be selected of the mobile terminal reporting is pre-
Phase RSRP；P is the transmission power of the current unmanned aerial vehicle onboard base station and the unmanned aerial vehicle onboard base station to be selected.
2. the method according to claim 1, wherein the training process of the prediction model includes:
Obtain the corresponding track point set of mobile terminal of default third quantity, wherein the track point set includes each movement
Terminal enter it is described it is overlapping covered before tracing point and each mobile terminal enter the overlapping coverage areas
Tracing point after domain；
The track point set is inputted into initial predicted model, training obtains the prediction model.
3. the method according to claim 1, wherein default second quantity determines as follows:
Default second quantity is calculated using following formula；
In formula, k is default second quantity；TTT is preset triggering duration；△ T is default first quantity
Time interval between historical track point；Ceil function is used to return to the smallest positive integral for being more than or equal to specified expression formula.
4. a kind of switching device of the unmanned aerial vehicle onboard base station based on user trajectory prediction, which is characterized in that described device includes:
Trigger condition judgement unit, trajectory predictions unit, switch decision unit and switching execution unit；
Whether the trigger condition judgement unit detects mobile terminal for the switch decision standard based on mobile communication
Into the overlapping covered of current service cell and serving cell to be selected, wherein current under current unmanned aerial vehicle onboard base station
Serving cell to be selected under serving cell and unmanned aerial vehicle onboard base station to be selected is neighboring community, the mobile terminal current home in
The current service cell；
The trajectory predictions unit, the history for default first quantity by the mobile terminal before reaching current location
Tracing point and the tracing point of the current location are determined as the input set for the prediction model trained in advance；Using described pre-
Model is surveyed, the expected trajectory point of default second quantity of the mobile terminal after reaching the current location is calculated, wherein
The prediction model is based on the regression prediction method in machine learning, for entering the overlapping coverage areas according to mobile terminal
The tracing point of historical track point and current location before domain, calculate mobile terminal enter it is described it is overlapping covered after
Expected trajectory point；
The switch decision unit is located at the calculated any institute of the trajectory predictions unit when the mobile terminal for judging
When stating expected trajectory point, whether the expected trajectory point corresponding default first expected RSRP and default second expected RSRP meets institute
State the switch decision standard of mobile communication, wherein the described first expected RSRP refers to when the mobile terminal is located at the expection rail
When mark point, pass through the pre- of the current unmanned aerial vehicle onboard base station of the calculated mobile terminal reporting of preset derivation formula
Phase RSRP, the second expected RSRP refer to when the mobile terminal is located at the expected trajectory point, preset is pushed away by described
Lead the expection RSRP of the unmanned aerial vehicle onboard base station to be selected of the calculated mobile terminal reporting of formula；
The switching execution unit, if the judging result for the switch decision unit is the described first expected RSRP and described
Second expected RSRP meets the switch decision standard of the mobile communication, then by the mobile terminal from the current service cell
Switch to the serving cell to be selected；
Wherein, the trajectory predictions unit, is also used for following formula, calculates separately when the mobile terminal is positioned at each described
When expected trajectory point, current unmanned plane horizontal plane where the mobile terminal project to the first of the mobile terminal away from
From and unmanned plane to be selected horizontal plane where the mobile terminal the second distance for projecting to the mobile terminal；
In formula, i=1,2；As i=1, d1For the current unmanned plane horizontal plane where the mobile terminal projection
To the first distance of the mobile terminal, (x1, y1) it is projection of the current unmanned plane in horizontal plane where the mobile terminal
Position coordinates；As i=2, d2The movement is projected in horizontal plane where the mobile terminal for the unmanned plane to be selected
The second distance of terminal, (x2, y2) it is projected position coordinate of the unmanned plane to be selected in horizontal plane where the mobile terminal；
(xc, yc) it is any desired guiding trajectory point coordinate；
The trajectory predictions unit, is also used for following formula, according to the first distance and the second distance, counts respectively
Calculate the first straight line of the current unmanned plane to the mobile terminal when the mobile terminal is located at each expected trajectory point
The second straight line distance of distance and the unmanned plane to be selected to the mobile terminal；
In formula, i=1,2；As i=1, s1For the first straight line distance of the current unmanned plane to the mobile terminal, h1
For the vertical range of horizontal plane where the current unmanned plane to the mobile terminal；As i=2, s2For it is described it is to be selected nobody
Second straight line distance of the machine to the mobile terminal, h2For hanging down for horizontal plane where the unmanned plane to be selected to the mobile terminal
Straight distance；
The trajectory predictions unit, is also used for following formula, according to the first straight line distance and the second straight line away from
From calculating separately when the mobile terminal is located at each expected trajectory point, the first free space of the current unmanned plane
Path loss and the unmanned plane to be selected the second free space path loss；
FSPLi=20loglog (si)+20loglog(fMHZ)-27.55
In formula, i=1,2；As i=1, FSPL1For the path loss of the first free space of the current unmanned plane；Work as i
When=2, FSPL2For the path loss of the second free space of the unmanned plane to be selected；fMHZFor the current unmanned aerial vehicle onboard base
It stands and the transmitting frequency range of the unmanned aerial vehicle onboard base station to be selected；
The trajectory predictions unit, is also used for following formula, according to the path loss of first free space and described
The path loss of second free space is calculated separately when the mobile terminal is located at each expected trajectory point, described current
The first average path loss for being subject to and the unmanned plane to be selected are to described when unmanned plane sends signal to the mobile terminal
Mobile terminal sends the second average path loss being subject to when signal；
PLi=FSPLi+ηi
In formula, i=1,2；As i=1, PL1The current unmanned plane is subject to when sending signal to the mobile terminal
First average path loss, η1For in the vacant lot that the mobile terminal by the aerial current unmanned plane and ground is formed
Jing Zhong, the default first extra path loss value that the current unmanned plane is subject to when sending signal to the mobile terminal；Work as i=
When 2, PL2The second average path loss being subject to when sending signal to the mobile terminal for the unmanned plane to be selected；η2For by
In the vacant lot scene that the mobile terminal of the aerial unmanned plane to be selected and ground is formed, the unmanned plane to be selected is to described
Mobile terminal sends the default second extra path loss value being subject to when signal；
The trajectory predictions unit, is also used for following formula, according to first average path loss and described second flat
Equal path loss is calculated separately when the mobile terminal is located at each expected trajectory point, the institute of the mobile terminal reporting
State the first expected RSRP of current unmanned aerial vehicle onboard base station and the unmanned aerial vehicle onboard base to be selected of the mobile terminal reporting
The expected RSRP of second to stand；
RSRPi=P-PLi
In formula, i=1,2；As i=1, RSRP1For the current unmanned aerial vehicle onboard base station of the mobile terminal reporting
First expected RSRP；As i=2, RSRP2Second for the unmanned aerial vehicle onboard base station to be selected of the mobile terminal reporting is pre-
Phase RSRP；P is the transmission power of the current unmanned aerial vehicle onboard base station and the unmanned aerial vehicle onboard base station to be selected.
5. device according to claim 4, which is characterized in that the prediction model is by executing as lower unit is default:
Acquiring unit, the corresponding track point set of mobile terminal for obtaining default third quantity, wherein the track point set
Close include each mobile terminal enter it is described it is overlapping covered before tracing point and each mobile terminal enter institute
State it is overlapping covered after tracing point；
Training unit, for the track point set to be inputted initial predicted model, training obtains the prediction model.
6. device according to claim 4, which is characterized in that default second quantity is by executing as lower unit is true
It is fixed:
The trajectory predictions unit is also used for following formula and calculates default second quantity；
In formula, k is default second quantity；TTT is preset triggering duration；△ T is default first quantity
Time interval between historical track point；Ceil function is used to return to the smallest positive integral for being more than or equal to specified expression formula.
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| EP4210394A1 (en) * | 2018-05-10 | 2023-07-12 | Beijing Xiaomi Mobile Software Co., Ltd. | Method for receiving reported flight path information, and base station for receiving said information |
| CN109314898B (en) * | 2018-08-07 | 2021-03-23 | 北京小米移动软件有限公司 | Method and device for transmitting flight information |
| CN109286435B (en) * | 2018-11-01 | 2021-11-23 | 上海歌尔泰克机器人有限公司 | Data transmission method, device and system |
| CN109743210B (en) * | 2019-01-25 | 2020-04-17 | 电子科技大学 | Unmanned aerial vehicle network multi-user access control method based on deep reinforcement learning |
| EP3966598A4 (en) * | 2019-05-07 | 2022-12-21 | Nokia Technologies OY | Privacy management |
| CN110430537B (en) * | 2019-07-30 | 2021-03-23 | 北京信成未来科技有限公司 | Unmanned aerial vehicle cellular communication base station selection method based on position information |
| CN110471448A (en) * | 2019-08-28 | 2019-11-19 | 中国联合网络通信集团有限公司 | A kind of unmanned plane during flying method and device |
| CN112449383A (en) * | 2019-08-28 | 2021-03-05 | 索尼公司 | Apparatus, method and storage medium for wireless communication system |
| CN112954749B (en) * | 2019-12-11 | 2022-05-10 | 华为技术有限公司 | Network switching method and electronic equipment |
| CN113133069A (en) * | 2020-01-10 | 2021-07-16 | 上海大唐移动通信设备有限公司 | Method and device for determining target cell, electronic equipment and storage medium |
| CN111343680B (en) * | 2020-03-02 | 2022-04-01 | 东南大学 | Switching time delay reduction method based on reference signal received power prediction |
| WO2021203389A1 (en) * | 2020-04-09 | 2021-10-14 | Oppo广东移动通信有限公司 | Communication method and apparatus, device, and storage medium |
| CN111954276B (en) * | 2020-08-14 | 2022-05-24 | 北京邮电大学 | Switching parameter setting method for unmanned aerial vehicle base station network |
| CN112965369B (en) * | 2021-01-29 | 2022-02-01 | 电子科技大学 | Distributed deployment method of three-dimensional wireless communication network of unmanned aerial vehicle |
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