Unmanned aerial vehicle communication perception integrated system beam forming and resource scheduling method
Technical Field
The invention belongs to the technical field of unmanned aerial vehicle communication, and relates to a beam forming and resource scheduling method of an unmanned aerial vehicle communication perception integrated system.
Background
The unmanned aerial vehicle is widely applied to the military and civil fields due to the characteristics of high maneuverability, low cost, strong concealment, easy deployment and the like, and can perform various tasks such as reconnaissance, tracking, accurate guidance, electromagnetic interference, material throwing and the like. Through deploying the communication and perception modules, the unmanned aerial vehicle can be used as a communication and perception integrated platform, and high-precision, flexible target perception and high-efficiency information interaction of multi-machine cooperation are realized. However, the unmanned aerial vehicle communication perception integrated system faces competition of multidimensional resources such as frequency spectrum, power and time slot between communication and perception functions, and interference inside the communication system and among systems, and how to design beam forming and resource allocation strategies to realize system performance optimization is a problem to be solved currently.
At present, the problem of resource allocation of an unmanned aerial vehicle communication perception integrated system is studied in literature, and if literature is based on the signal-to-interference-and-noise ratio limiting condition of a receiving end of a perception system, a resource allocation scheme is designed to optimize the transmission rate of a communication system. It is also studied to design the transmission signal of the sensing system to optimize the signal-to-interference-and-noise ratio of the sensing system under the condition that the communication system can tolerate interference. However, the existing research rarely considers the joint optimization of communication and perception system performance, and the problems of beam forming and bistatic SAR perception trajectory design of the unmanned aerial vehicle multi-input multi-output MIMO communication system, which results in serious limitation of system performance.
Disclosure of Invention
In view of the above, the present invention aims to provide a beam forming and resource scheduling method for an unmanned aerial vehicle communication perception integrated system. Aiming at a system scene comprising 1 main unmanned aerial vehicle, 1 secondary unmanned aerial vehicle, K users and G perception targets, modeling is carried out to minimize communication time, maximize correlation coefficient and minimize unmanned aerial vehicle flight energy consumption as optimization targets, and the combined optimization of unmanned aerial vehicle beam forming, association strategy and flight track is realized.
In order to achieve the above purpose, the present invention provides the following technical solutions:
A beam forming and resource scheduling method of an unmanned aerial vehicle communication perception integrated system comprises the following steps:
S1, modeling an unmanned aerial vehicle communication perception integrated system model; the system model specifically comprises the following steps: the system comprises 1 main unmanned aerial vehicle, 1 secondary unmanned aerial vehicle, K users and G perception targets, wherein the number of transmitting antennas of the main unmanned aerial vehicle is M, and the number of receiving antennas of the users is N; the main unmanned aerial vehicle configures airborne communication equipment, and sends data to communication users based on a multiple-input multiple-output (MIMO) technology; the secondary unmanned aerial vehicle is configured with an airborne radar receiver, and forms a bistatic SAR with the main unmanned aerial vehicle, and receives a target echo signal so as to sense target information; the coordinates of the kth user are expressed as: q k=[xk,yk, where K is equal to or greater than 1 and equal to or less than K, and the g-th perception target coordinates are expressed as: The deployment location of the master drone is expressed as: q c=[xc,yc ]; discretizing the system time into T time slots, wherein the length of each time slot is tau; the position of the secondary drone at the t slot is expressed as: q s(t)=[xs(t),ys (t) ]; the main unmanned aerial vehicle is respectively communicated with K users, the target receives the communication signals of the main unmanned aerial vehicle and then reflects signals, and the secondary unmanned aerial vehicle receives the reflected signals of the target and then perceives the target;
S2, modeling an unmanned aerial vehicle communication channel model;
s3, modeling a communication signal of the unmanned aerial vehicle;
s4, modeling the communication rate and the communication time of the user;
s5, modeling target perception resolution and perception associated variables;
S6, modeling unmanned aerial vehicle signal power constraint and flight energy consumption;
s7, modeling unmanned aerial vehicle resource scheduling and flight trajectory constraint;
S8, determining unmanned aerial vehicle beam forming, association strategy and flight track based on system performance optimization.
Further, the step S2 specifically includes: let h k,n,m (t) represent the channel gain of the link between the mth antenna of the main unmanned aerial vehicle with t time slots and the nth antenna of the kth user, comprehensively consider the channel transmission loss and the random fading characteristic, and model as follows:
Wherein ρ 0 represents a channel loss coefficient per unit distance, L represents a deployment height of the main unmanned aerial vehicle, χ k,n,m (t) represents a small-scale MIMO antenna performance gain;
Let H k(t)∈CN×M represent the communication channel matrix between the t-slot master drone and user k, modeled as:
[Hk(t)]n,m=hk,n,m(t)。
Further, the step S3 specifically includes: let x k (t) represent the signal sent by the t-slot master drone to user k, modeled as:
xk(t)=αk(t)Wk(t)ck
where α k (t) ∈ {0,1} represents a user communication variable, α k (t) =1 represents that the master drone communicates with user k in t slots, whereas α k(t)=0;Wk(t)∈CM×N is a communication beamforming matrix of the master drone to user k in t slots, and c k∈CN×1 represents a communication signal of user k.
Further, the step S4 specifically includes: assuming that the t-slot master drone communicates with user k, the received signal power for user k is modeled as:
The interference power received by user k from other antennas is modeled as:
let γ k (t) denote the signal-to-interference-and-noise ratio of user k at time slot t, modeled as:
Wherein σ 2 represents the noise power;
Let R k (t) denote the communication rate of user k at time t slot, modeled as:
Rk(t)=αk(t)B log2(1+γk(t))
Wherein B is the communication bandwidth of the main unmanned aerial vehicle;
Order the The starting time slot representing the communication between the master drone and user k is modeled as:
Order the The end time slot representing the communication between the master drone and user k is modeled as:
let T k denote the duration of communication between the master drone and user k, modeled as:
Let T 0 represent the total duration of the main unmanned aerial vehicle communication, modeled as:
further, the step S5 specifically includes: assuming that the target g is perceived by the t-time-slot secondary unmanned aerial vehicle, the perceived area can be approximately a circular area, and the radius of the perceived area is R;
Let q o (t) represent the coordinates of the t-slot secondary unmanned perception center O, modeled as:
qo(t)=[xo(t),yo(t)]
xo(t)=xs(t)+H tanηsin(θs(t))
yo(t)=ys(t)-H tanηcos(θs(t))
Wherein H represents the flight altitude of the secondary unmanned aerial vehicle, Representing the observation angle of the side-looking SAR receiver of the secondary unmanned aerial vehicle; θ s (t) epsilon (0, 2 pi) represents an included angle between the course of the unmanned aerial vehicle and the X axis for t times in a time slot;
Order the The included angle between the connecting line and the vertical direction between the main unmanned aerial vehicle and the perception center O is modeled as follows:
Let δ r (t) and δ a (t) represent the distance resolution and azimuth resolution of the slot t-aware region, respectively, modeled as:
Wherein c represents the speed of light, λ represents the signal wavelength, and T d represents the SAR coherent integration time;
let ζ k,g represent the correlation coefficient of user k with perceived target g, modeled as:
let ζ represent the sum of correlation coefficients between the user and the perceived target, modeled as:
Order the Representing the matching variable between the user and the target,Indicating that user k matches perception target g, and vice versa,
Let β g (t) ∈ {0,1} be the target perception variable, β g (t) =1 represent that the secondary drone perceives the target g in t slots, whereas β g (t) =0, modeled as:
Wherein ω g (t) ∈ {0,1} represents an indicator variable, and ω g (t) =1 represents that the secondary unmanned plane satisfies the perception target g in t time slots Conversely, ω g (t) =0.
Further, the step S6 specifically includes: assuming that the t-slot main unmanned aerial vehicle communicates with the user k, let P c,k (t) represent the transmission power corresponding to the transmission communication signal of the t-slot main unmanned aerial vehicle, and modeling is as follows:
Pc,k(t)=Tr[Rk(t)]
The communication power of the main unmanned aerial vehicle needs to be lower than the given maximum power The constraint modeling is:
Let E s represent the energy consumed by the secondary unmanned aerial vehicle flight, modeled as:
Wherein, P f (t) represents the propulsion power required by the secondary unmanned aerial vehicle to fly in the time slot t, and is expressed as:
Where k 1,k2 represents the unmanned aerial vehicle flight energy coefficient.
Further, the step S7 specifically includes: any slot master drone communicates with at most one user, the constraint being expressed as:
The communication time slots of the master drone with one user are continuous, and the constraint is expressed as:
Let D k be the data volume that the primary unmanned aerial vehicle needs to transmit to user k, then the primary unmanned aerial vehicle data transmission constraint is expressed as:
Matching K users with G perception targets, wherein each perception target is required to be matched with one user, and the constraint is expressed as:
let d min be the given minimum resolution requirement, then the secondary drone perceived resolution constraint is expressed as:
The time required for the secondary drone's perception of the target g is greater than a given time T g, the constraint being expressed as:
After the secondary unmanned aerial vehicle finishes the perception task, the secondary unmanned aerial vehicle needs to fly back to the starting point, and the constraint is expressed as: q s(0)=qs (T);
Let V max be the maximum flight speed of the secondary unmanned aerial vehicle, then the secondary unmanned aerial vehicle speed constraint is expressed as:
Further, the step S8 specifically includes: the modeling system performance metrics were: t 0,ξ,Es; determining a beam forming matrix W k (t) based on system performance optimization, a primary unmanned aerial vehicle deployment position q c, a secondary unmanned aerial vehicle track q s (t) and an association strategy alpha k (t), And β g (t), yielding:
In the method, in the process of the invention, The method comprises the steps of respectively optimizing a communication beam matrix, a primary unmanned aerial vehicle deployment position, a secondary unmanned aerial vehicle track, a communication association variable, a communication perception matching variable and a perception association variable.
The invention has the beneficial effects that: aiming at a system scene comprising 1 multi-antenna main unmanned aerial vehicle, 1 sub-unmanned aerial vehicle, a plurality of users and a plurality of perception targets, the method models to minimize communication time, maximize correlation coefficient and minimize unmanned aerial vehicle flight energy consumption as optimization targets, and realizes the combined optimization of unmanned aerial vehicle beam forming, correlation strategy and flight track.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objects and other advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the specification.
Drawings
For the purpose of making the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in the following preferred detail with reference to the accompanying drawings, in which:
fig. 1 is a schematic view of a scene of an unmanned aerial vehicle communication perception fusion system;
Fig. 2 is a schematic flow chart of a beam forming and resource scheduling method of an unmanned aerial vehicle communication perception integrated system.
Detailed Description
Other advantages and effects of the present invention will become apparent to those skilled in the art from the following disclosure, which describes the embodiments of the present invention with reference to specific examples. The invention may be practiced or carried out in other embodiments that depart from the specific details, and the details of the present description may be modified or varied from the spirit and scope of the present invention. It should be noted that the illustrations provided in the following embodiments merely illustrate the basic idea of the present invention by way of illustration, and the following embodiments and features in the embodiments may be combined with each other without conflict.
Aiming at a system scene comprising 1 main unmanned aerial vehicle, 1 secondary unmanned aerial vehicle, K users and G perception targets, the invention models the minimum communication time, the maximum correlation coefficient and the minimum unmanned aerial vehicle flight energy consumption as optimization targets, and realizes the combined optimization of unmanned aerial vehicle beam forming, correlation strategy and flight track.
Specifically, the system scene is shown in fig. 1, 1 main unmanned aerial vehicle, 1 secondary unmanned aerial vehicle, K users and G perception targets exist in the scene, the number of transmitting antennas of the main unmanned aerial vehicle is M, the number of receiving antennas of the users is N, and the main unmanned aerial vehicle is configured with airborne communication equipment and can send data to communication users based on a multiple-input multiple-output (MIMO) technology. The secondary unmanned aerial vehicle is configured with an airborne radar receiver, and forms a bistatic SAR with the main unmanned aerial vehicle, and receives a target echo signal so as to sense target information. The main unmanned aerial vehicle is respectively communicated with K users, the target receives the communication signals of the main unmanned aerial vehicle and then reflects signals, and the secondary unmanned aerial vehicle receives the reflected signals of the target and then perceives the target.
For the above system scenario, the method for beam forming and resource scheduling of the unmanned aerial vehicle communication perception integrated system provided by the invention is shown in fig. 2, and specifically includes:
1) Modeling an unmanned aerial vehicle communication perception integrated system model;
modeling an unmanned aerial vehicle communication perception integrated system model, wherein the system comprises 1 main unmanned aerial vehicle, 1 secondary unmanned aerial vehicle, K users and G perception targets, the number of transmitting antennas of the main unmanned aerial vehicle is M, and the number of receiving antennas of the users is N; the main unmanned plane is configured with an onboard communication device, and can send data to a communication user based on a multiple-input multiple-output (MIMO) technology; the secondary unmanned aerial vehicle is configured with an airborne radar receiver, and forms a bistatic SAR with the main unmanned aerial vehicle, and receives a target echo signal so as to sense target information;
The coordinates of the kth user are expressed as: q k=[xk,yk, wherein K is more than or equal to 1 and less than or equal to K, and the g-th perception target coordinates are as follows: G is more than or equal to 1 and less than or equal to G; the deployment location of the master drone is expressed as: q c=[xc,yc ]; discretizing the system time into T time slots, wherein the length of each time slot is tau; the position of the secondary drone at the t slot is expressed as: q s(t)=[xs(t),ys (t) ]; the main unmanned aerial vehicle is respectively communicated with K users, the target receives the communication signals of the main unmanned aerial vehicle and then reflects signals, and the secondary unmanned aerial vehicle receives the reflected signals of the target and then perceives the target.
2) Modeling an unmanned aerial vehicle communication channel model;
Modeling an unmanned aerial vehicle communication channel model, specifically comprising:
let h k,n,m (t) represent the channel gain of the link between the mth antenna of the main unmanned aerial vehicle with t time slots and the nth antenna of the kth user, comprehensively consider the channel transmission loss and the random fading characteristics, and can be modeled as follows:
Wherein ρ 0 represents the channel loss coefficient of unit distance, L represents the deployment height of the main unmanned aerial vehicle, χ k,n,m (t) represents the performance gain of the small-scale MIMO antenna, and the complex Gaussian distribution random variable with the mean value of 0 and the variance of 1 is modeled;
Let H k(t)∈CN×M denote the communication channel matrix between the t-slot master drone and user k, which can be modeled as:
[Hk(t)]n,m=hk,n,m(t)
3) Modeling the unmanned aerial vehicle communication signal;
Modeling unmanned aerial vehicle communication signals, specifically includes:
Let x k (t) represent the signal sent by the t-slot master drone to user k, which can be modeled as:
xk(t)=αk(t)Wk(t)ck
Wherein α k (t) ∈ {0,1} represents a user communication variable, α k (t) =1 represents that the master unmanned aerial vehicle communicates with user k in t time slots, whereas α k(t)=0;Wk(t)∈CM×N is a communication beamforming matrix of the master unmanned aerial vehicle to user k in t time slots, c k∈CN×1 is a communication signal of user k, and can be modeled as:
4) Modeling user communication rate and communication time;
modeling the communication rate and communication time of a user specifically includes:
assuming that the t-slot master drone communicates with user k, the received signal power for user k can be modeled as:
The interference power received by user k from other antennas can be modeled as:
let γ k (t) denote the signal-to-interference-and-noise ratio of user k at time t, which can be modeled as:
Wherein σ 2 represents the noise power;
Let R k (t) denote the communication rate of user k at time t, which can be modeled as:
Rk(t)=αk(t)B log2(1+γk(t))
B is the communication bandwidth of the main unmanned aerial vehicle;
Order the The starting time slot representing the communication of the master drone with user k can be modeled as:
Order the The end time slot representing the communication of the master drone with user k can be modeled as:
Let T k denote the duration of the communication between the master drone and user k, which can be modeled as:
Let T 0 denote the total duration of the primary drone communication, which can be modeled as:
5) Modeling target perception resolution and perception associated variables;
Modeling target perception resolution and perception associated variables specifically comprises:
Assuming that the target g is perceived by the t-time-slot secondary unmanned aerial vehicle, the perceived area can be approximately a circular area, and the radius of the perceived area is R;
Let q o (t) represent the coordinates of the t-slot secondary unmanned perception center O, which can be modeled as:
qo(t)=[xo(t),yo(t)]
Wherein ,xo(t)=xs(t)+H tanηsin(θs(t)),yo(t)=ys(t)-H tanηcos(θs(t)),H is the secondary unmanned aerial vehicle flight altitude, Viewing an observation angle of the SAR receiver for the secondary unmanned aerial vehicle side; θ s (t) ∈ (0, 2 pi) represents the angle between the heading of the unmanned aerial vehicle and the X axis for t times in a time slot, and can be modeled as follows:
where v (t) represents the speed of the secondary unmanned aerial vehicle at time slot t, and can be modeled as
Order theThe included angle between the connecting line and the vertical direction between the main unmanned plane and the perception center O can be modeled as follows:
Let δ r (t) and δ a (t) represent the distance resolution and azimuth resolution, respectively, of the perceived region of the slot t, which can be modeled as:
Wherein c is the speed of light, lambda is the signal wavelength, and T d is SAR coherent integration time;
Let ζ k,g represent the correlation coefficient of user k with perceived target g, which can be modeled as:
Let ζ represent the sum of the correlation coefficients between the user and the perceived target, which can be modeled as:
Order the Representing the matching variable between the user and the target,Indicating that user k matches perception target g, and vice versa,
Let β g (t) ∈ {0,1} be the target perception variable, β g (t) =1 represent that the secondary drone perceives the target g in t slots, whereas β g (t) =0 can be modeled as:
wherein ω g (t) ∈ {0,1} is an indicator variable, and ω g (t) =1 indicates that the secondary unmanned plane satisfies the perception target g in t time slots Conversely, ω g (t) =0.
6) Modeling unmanned aerial vehicle signal power constraint and flight energy consumption;
Modeling unmanned aerial vehicle signal power constraint and flight energy consumption specifically includes:
assuming that the t-slot master drone communicates with the user k, let P c,k (t) represent the transmission power corresponding to the transmission communication signal of the t-slot master drone, which can be modeled as:
Pc,k(t)=Tr[Rk(t)]
Wherein,
The communication power of the main unmanned aerial vehicle needs to be lower than the given maximum powerThe constraint can be modeled as:
Let E s represent the energy consumed by the secondary unmanned aerial vehicle flight, which can be modeled as:
Wherein, P f (t) represents the propulsion power required by the secondary unmanned aerial vehicle to fly in the time slot t, which can be expressed as:
Wherein k 1,k2 is the unmanned aerial vehicle flight energy coefficient.
7) Modeling unmanned aerial vehicle resource scheduling and flight trajectory constraint;
Modeling unmanned aerial vehicle resource scheduling and flight trajectory constraint specifically includes:
any slot master drone communicates with at most one user, the constraint can be expressed as:
the communication time slots of the master drone with one user are continuous, and the constraint can be expressed as:
Let D k be the data volume that the primary drone needs to transmit to user k, then the primary drone data transmission constraint may be expressed as:
matching K users with G perception targets, wherein each perception target needs to be matched with one user, and the constraint can be expressed as follows:
Let d min be the given minimum resolution requirement, then the secondary drone perceived resolution constraint can be expressed as:
The time required for the secondary drone's perception of target g is greater than a given time T g, and the constraint can be expressed as:
After the secondary unmanned aerial vehicle finishes the perception task, the secondary unmanned aerial vehicle needs to fly back to the starting point, and the constraint can be expressed as: q s(0)=qs (T);
Let V max be the maximum flight speed of the secondary unmanned aerial vehicle, the secondary unmanned aerial vehicle speed constraint may be expressed as:
8) Determining unmanned aerial vehicle beam forming, association strategy and flight track based on system performance optimization;
Determining unmanned aerial vehicle beam forming, association strategy and flight trajectory based on system performance optimization, specifically comprising:
The modeling system performance metrics were: t 0,ξ,Es; determining a beam forming matrix W k (t) based on system performance optimization, a primary unmanned aerial vehicle deployment position q c, a secondary unmanned aerial vehicle track q s (t) and an association strategy alpha k (t), And β g (t), yielding:
Wherein, The method comprises the steps of respectively optimizing a communication beam matrix, a primary unmanned aerial vehicle deployment position, a secondary unmanned aerial vehicle track, a communication association variable, a communication perception matching variable and a perception association variable.
Finally, it is noted that the above embodiments are only for illustrating the technical solution of the present invention and not for limiting the same, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications and equivalents may be made thereto without departing from the spirit and scope of the present invention, which is intended to be covered by the claims of the present invention.