Wireless self-organizing network interruption compensation method and device
阅读说明：本技术 无线自组织网络中断补偿方法及装置 (Wireless self-organizing network interruption compensation method and device ) 是由 喻鹏 李文璟 丰雷 周凡钦 陈成 于 2021-08-30 设计创作，主要内容包括：本发明提供一种无线自组织网络中断补偿方法及装置,该方法包括：任一小区中断后,根据目标区域内所有用户终端重新分配至各基站进行服务的多种分配方式,以及每个基站对天线下倾角、天线方位角和所服务用户终端功率的多种分配方式,确定多个不同的基站服务用户终端的分配方案；从多个不同的分配方案中确定使所有用户终端的加权传输速率最大的分配方案,作为补偿后的分配方案。该方法针对影响用户服务质量和基站功效的关键参数进行调节,比单一参数调节更加灵活。使用用户传输速率来衡量优化效果,能够真实的反映优化带来的改变,且能够优先满足比较重要的业务,在用户密度较高或者较多基站发生中断的场合下,能够尽量满足高优先级用户的服务需求。(The invention provides a method and a device for interruption compensation of a wireless self-organizing network, wherein the method comprises the following steps: after any cell is interrupted, determining a distribution scheme of a plurality of different base station service user terminals according to a plurality of distribution modes of all user terminals in a target area redistributed to each base station for service and a plurality of distribution modes of each base station for antenna downward inclination angles, antenna azimuth angles and power of the service user terminals; an allocation scheme that maximizes the weighted transmission rates of all user terminals is determined from a plurality of different allocation schemes as a compensated allocation scheme. The method adjusts key parameters influencing the service quality of the user and the efficiency of the base station, and is more flexible than single parameter adjustment. The optimization effect is measured by using the user transmission rate, changes caused by optimization can be truly reflected, more important services can be preferentially met, and the service requirements of high-priority users can be met as much as possible on occasions with higher user density or interruption of more base stations.)
1. A method for compensating for interruption of a wireless ad hoc network, comprising:
after any cell in the target area is interrupted, determining a distribution scheme of a plurality of different base stations for serving user terminals according to a plurality of distribution modes of all user terminals in the target area redistributed to each base station in the target area for serving and a plurality of distribution modes of each base station for antenna downward inclination angles, antenna azimuth angles and power of the served user terminals;
determining an allocation scheme that maximizes the weighted transmission rates of all user terminals from among the allocation schemes of the plurality of different base station serving user terminals as a compensated allocation scheme.
2. The method of claim 1, wherein the determining an allocation scheme that maximizes the weighted transmission rates of all user terminals from among the allocation schemes for serving user terminals from the plurality of different base stations further comprises, before the allocation scheme after compensation:
determining the signal-to-noise ratio between the base station and the user according to the channel gain between the base station and the user, the downlink transmission power provided by the base station for the user and the total transmission power of the base station;
and determining the transmission rate of the user according to the signal-to-noise ratio.
3. The method of claim 2, wherein before determining the snr between the base station and the user according to the channel gain between the base station and the user, the downlink transmission power provided by the base station for the user, and the total transmit power of the base station, the method further comprises:
respectively determining horizontal antenna gain and vertical antenna gain according to a horizontal azimuth angle and a vertical azimuth angle between a user and a base station;
determining the total antenna gain between the base station and the user according to the horizontal antenna gain and the vertical antenna gain;
and determining the channel gain between the user and the base station according to the total antenna gain and the user equipment gain.
4. The method according to any of claims 1-3, wherein the determining the allocation scheme that maximizes the weighted transmission rate of all the ues from among the allocation schemes of the ues served by the plurality of different bss further comprises, before the allocation scheme after compensation:
determining a coverage radius of each base station;
for any two base stations m and n, determining the connection relation between the base stations according to the following formula:
determining that the sum of the number of connections between all base stations in any allocation scheme is greater than a preset threshold;
wherein d ism,nIs the distance between base stations m and n, rm、rmThe coverage radius of base stations m and n, respectively.
5. The method of claim 1, wherein the determining an allocation scheme that maximizes the weighted transmission rates of all user terminals from among the allocation schemes for serving user terminals from the plurality of different base stations as the compensated allocation scheme comprises:
taking each distribution scheme as a particle of a particle swarm algorithm, and initializing the value, the particle position and the particle speed of each particle;
calculating the fitness of each particle by taking the weighted transmission rate of the user as a fitness function, and updating the historical optimal position and the global optimal position of each particle;
dividing the particles into advanced particles and common particles according to the fitness, and updating the common particles and the advanced particles;
if the fitness of the updated position of the advanced particles is lower than that of the position before updating, rolling back to the position before updating, generating a chaotic point row based on the current position by adopting a chaotic mapping mode, and selecting a point with the highest fitness as a new position until the updating of all the particles is completed;
repeating the calculation of the fitness of each particle, updating the historical optimal position and the global optimal position of each particle, updating common particles and advanced particles until the iterative process of updating all the particles is completed until the preset iterative times are reached;
and selecting the particles with the maximum fitness function value as the distribution scheme after compensation.
6. The method of claim 5, wherein the updating the normal particles and the advanced particles comprises:
determining an inertia factor according to the fitness function and the historical optimal position;
and updating the common particles and the advanced particles according to the inertia factor, the historical optimal position and the global optimal position.
7. The interruption compensation method for the wireless ad hoc network according to claim 5, wherein the generating of the chaotic point sequence based on the current position by using the chaotic mapping method comprises:
tent mapping is carried out according to the particles at the current position, three dimensional parameters of the downward inclination angle and the azimuth angle of the antenna in each particle and the power distribution of a user are mapped to a 0-1 interval according to the following formula:
after iteration for M times, obtaining a chaos sequence
And updating each dimension parameter in the particle k according to the following formula:
wherein [ a ]l,bl]For each dimension of the parameter, xklThe i-dimension parameter of the k-th particle is represented.
8. A wireless ad hoc network outage compensation apparatus, comprising:
the distribution module is used for determining the distribution schemes of a plurality of different base station service user terminals according to a plurality of distribution modes of redistributing all the user terminals in the target area to each base station in the target area for service after any cell in the target area is interrupted and a plurality of distribution modes of each base station for antenna downward inclination angles, antenna azimuth angles and power of the service user terminals;
and a processing module, configured to determine, from the allocation schemes for serving the user terminals by the multiple different base stations, an allocation scheme that maximizes the weighted transmission rates of all the user terminals as a compensated allocation scheme.
9. An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor when executing the program performs the steps of the method for interruption compensation in a wireless ad hoc network according to any one of claims 1 to 7.
10. A non-transitory computer readable storage medium, having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the method for wireless ad hoc network outage compensation according to any of claims 1 to 7.
Technical Field
The present invention relates to the field of wireless communications, and in particular, to a method and an apparatus for compensating for an interruption in a wireless ad hoc network.
Background
With the development of the 5G network, the network will be developed from a simple communication service between a provider and a person to a provider and a connection between an object and a person, so as to provide more diverse informationized services, therefore, more strict requirements are provided for network management and self-optimization, the 5G network must have more extensive sensing capability and self-optimization capability, the reliability and intelligence of the network are improved, the spectrum efficiency is improved, the network sensing of a user is improved, the network occurrence probability is reduced, the intellectualization and automation degree of network operation and maintenance are improved, and the fault self-diagnosis and self-optimization are realized.
The self-organizing network is a network operation and maintenance strategy proposed by 3GPP, mainly comprising three functions of self-configuration, self-healing and self-optimization. The self-configuration function mainly comprises self-configuration of the base station and self-management in the operation process, and automatic management of the base station can be realized in the whole working period of the base station, and the automatic management comprises creation, automatic test, automatic IP address acquisition, automatic configuration of related parameters, adjacent region planning and the like of the base station. The self-configuration function greatly reduces the manual operation and maintenance cost and reduces the expenditure of network infrastructure construction. The self-healing function mainly processes network element faults in the network, and the function firstly analyzes fault information by monitoring equipment in the network in real time when a fault warning occurs, then automatically or manually executes a solution measure, and reports the fault information after the fault processing is finished so as to be used for system learning, namely fault backup and the like. The self-optimization function mainly refers to optimizing network performance by self-adaptively adjusting parameters in network equipment and the like, the optimization of a wireless network mainly comprises parameter optimization and mechanical optimization, and the self-optimization function of the self-organizing network comprises a plurality of technologies.
At present, most of cell outage compensation methods in a wireless ad hoc network are realized based on a single parameter, and mainly include two types of network parameter optimization configuration and mechanical optimization. The optimization of network parameters comprises downlink transmission power, channels and the like, the mechanical optimization comprises the downtilt angle, the azimuth angle and the like of an antenna, and the interruption compensation is realized by adjusting certain parameters of neighbor cells of an interruption cell. However, most schemes only consider one point, so that the applicability is not strong, and a good optimization effect cannot be achieved in a network environment with complicated and various networks in the future. In addition, for the user-intensive area, if the network compensation cannot meet the normal requirements of all users, the current method cannot dynamically adjust the power distribution and mechanical parameters according to the service characteristics, so that important service requirements can be guaranteed preferentially.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides a method and a device for interruption compensation of a wireless self-organizing network.
The invention provides a wireless self-organizing network interruption compensation method, which comprises the following steps: after any cell in the target area is interrupted, determining a distribution scheme of a plurality of different base stations for serving user terminals according to a plurality of distribution modes of all user terminals in the target area redistributed to each base station in the target area for serving and a plurality of distribution modes of each base station for antenna downward inclination angles, antenna azimuth angles and power of the served user terminals; determining an allocation scheme that maximizes the weighted transmission rates of all user terminals from among the allocation schemes of the plurality of different base station serving user terminals as a compensated allocation scheme.
According to an embodiment of the present invention, before determining an allocation scheme that maximizes weighted transmission rates of all user terminals from among allocation schemes for serving the user terminals by the plurality of different base stations, the method further includes: determining the signal-to-noise ratio between a base station and a user according to the channel gain between the user and the base station, the downlink transmission power provided by the base station for the user and the total transmission power of the base station; and determining the transmission rate of the user according to the signal-to-noise ratio.
Before determining the signal-to-noise ratio between the base station and the user according to the channel gain between the user and the base station, the downlink transmission power provided by the base station for the user and the total transmission power of the base station, the method for compensating the interruption of the wireless self-organizing network according to an embodiment of the present invention further comprises: respectively determining horizontal antenna gain and vertical antenna gain according to a horizontal azimuth angle and a vertical azimuth angle between a user and a base station; determining the total antenna gain between the base station and the user according to the horizontal antenna gain and the vertical antenna gain; and determining the channel gain between the user and the base station according to the total antenna gain and the user equipment gain.
According to an embodiment of the present invention, before determining an allocation scheme that maximizes weighted transmission rates of all user terminals from among allocation schemes for serving the user terminals by the plurality of different base stations, the method further includes: determining a coverage radius of each base station; for any two base stations m and n, determining the connection relation between the base stations according to the following formula:
determining that the sum of the number of connections between all base stations in any allocation scheme is greater than a preset threshold;
wherein d ism,nIs the distance between base stations m and n, rm、rmThe coverage radius of base stations m and n, respectively.
According to an embodiment of the present invention, the method for compensating for interruption of a wireless ad hoc network, where the allocation scheme with the largest weighted transmission rate of all the ues is determined from the allocation schemes of the plurality of different ues served by the base station, and the method for compensating for interruption of a wireless ad hoc network includes: taking each distribution scheme as a particle of a particle swarm algorithm, and initializing the value, the particle position and the particle speed of each particle; calculating the fitness of each particle by taking the weighted transmission rate of the user as a fitness function, and updating the historical optimal position and the global optimal position of each particle; dividing the particles into advanced particles and common particles according to the fitness, and updating the common particles and the advanced particles; if the fitness of the updated position of the advanced particles is lower than that of the position before updating, rolling back to the position before updating, generating a chaotic point row based on the current position by adopting a chaotic mapping mode, and selecting a point with the highest fitness as a new position until the updating of all the particles is completed; repeating the calculation of the fitness of each particle, updating the historical optimal position and the global optimal position of each particle, updating common particles and advanced particles until the iterative process of updating all the particles is completed until the preset iterative times are reached; and selecting the particles with the maximum fitness function value as the distribution scheme after compensation.
According to an embodiment of the present invention, the method for compensating for interruption of a wireless ad hoc network, which updates the normal particles and the advanced particles, includes: determining an inertia factor according to the fitness function and the historical optimal position; and updating the common particles and the advanced particles according to the inertia factor, the historical optimal position and the global optimal position.
According to an embodiment of the invention, the method for compensating the interruption of the wireless self-organizing network, which generates the chaos point array based on the current position by adopting a chaos mapping mode, comprises the following steps: tent mapping is carried out according to the particles at the current position, three dimensional parameters of downward inclination angle setting, azimuth angle setting and user power distribution of each particle antenna are mapped to a 0-1 interval according to the following formula:
after iteration for M times, obtaining a chaos sequence
Updating each dimension parameter in the particle k according to the following formula;
wherein [ a ]l,bl]For each dimension of the parameter, xklThe i-dimension parameter of the k-th particle is represented.
The invention also provides a wireless self-organizing network interruption compensation device, which comprises: the distribution module is used for determining the distribution schemes of a plurality of different base station service user terminals according to a plurality of distribution modes of redistributing all the user terminals in the target area to each base station in the target area for service after any cell in the target area is interrupted and a plurality of distribution modes of each base station for antenna downward inclination angles, antenna azimuth angles and power of the service user terminals; a processing module, configured to determine, from the allocation schemes of the plurality of different base stations serving the user terminals, an allocation scheme that maximizes the weighted transmission rates of all the user terminals as a compensated allocation scheme.
The present invention also provides an electronic device, which includes a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the method for compensating for an outage in a wireless ad hoc network as described in any one of the above.
The present invention also provides a non-transitory computer readable storage medium having stored thereon a computer program which, when executed by a processor, performs the steps of the method for wireless ad hoc network outage compensation as described in any one of the above.
The method and the device for the interruption compensation of the wireless self-organizing network comprehensively consider the optimization of wireless parameters and the optimization of mechanical parameters, are suitable for various application scenes, adjust key parameters influencing the service quality of a user and the efficiency of a base station, and are more flexible than single parameter adjustment. The optimization effect is measured by using the user transmission rate, changes caused by optimization can be truly reflected, the services of the users are classified, more important services can be preferentially met, and the service requirements of the users with high priority can be met as much as possible on occasions with high user density or interruption of more base stations.
Drawings
In order to more clearly illustrate the technical solutions of the present invention or the prior art, the drawings needed for the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and those skilled in the art can also obtain other drawings according to the drawings without creative efforts.
Fig. 1 is a schematic flow chart of a method for compensating for interruption of a wireless ad hoc network provided by the present invention;
fig. 2 is a schematic structural diagram of a wireless ad hoc network outage compensation apparatus provided in the present invention;
fig. 3 is a schematic structural diagram of an electronic device provided in the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The method and apparatus for compensating for interruption in a wireless ad hoc network according to the present invention will be described with reference to fig. 1 to 3. Fig. 1 is a schematic flow chart of a method for compensating for an interruption in a wireless ad hoc network provided by the present invention, and as shown in fig. 1, the method for compensating for an interruption in a wireless ad hoc network provided by the present invention includes:
101. after any cell in the target area is interrupted, determining a distribution scheme of a plurality of different base stations for serving the user terminals according to a plurality of distribution modes of all the user terminals in the target area redistributed to each base station in the target area for serving and a plurality of distribution modes of each base station for antenna downward inclination angles, antenna azimuth angles and power of the served user terminals.
When the wireless ad hoc network interruption compensation model is established, key factors influencing the service quality of a user need to be considered, wherein the key factors comprise downlink transmission power provided by a base station to the user and the direction angle and the downward inclination angle of an antenna.
There are several cells in a certain area, where a certain cell is interrupted. Assuming that the number of base stations of a target area cell is M, the number of users is N, wherein the base stations have two states, namely interrupted State or normal operation, and assuming that the State of the base stations is StateiThen, the value of the base station state is:
users in the disrupted cell need to allocate a new base station and users in the uninterrupted cell may also need to tune to the new base station to free up resources.
Using the symbol SijThe state of any user j served by the base station i is represented as follows:
thus corresponding to the new subscriber and base station service allocation result.
And on the basis of the distribution result, adjusting the downward inclination angle and the azimuth angle of the antenna of each base station, and distributing the power of the base station distribution user to obtain different distribution schemes.
102. Determining an allocation scheme that maximizes the weighted transmission rates of all user terminals from among the allocation schemes of the plurality of different base station serving user terminals as a compensated allocation scheme.
The optimization objective of the method is to maximize the weighted transmission rate of all users, assuming a user group with three priorities, N respectively1，N2，N3The corresponding weights are respectively alpha1，α2，α3Then the optimization function is:
wherein the content of the first and second substances,and Cj3Respectively the transmission rates of different priority user groups.
In a preferred embodiment, the objective function may include some or all of the following constraints:
1)indicating that the total number of service relationships equals the total number of users for all base stations and users in the area;
2)meaning that for a user, only one base station can serve at a time;
3)means that for a certain user, the obtained transmission power must be equal to or greater than its minimum received power;
4)the state value is equal to 1, no matter whether the base station is connected with a user or not, the state value is equal to or larger than a connection relation value, if the base station is in an interruption state, the base station cannot be connected with any user, the state value is 0, and the service relation value is 0;
5)indicates the total work that can be provided to the user for any base stationThe sum of the rates is necessarily less than or equal to the maximum power of the base station, where Pi MAXRepresenting the maximum downlink power of the base station;
6)meaning that for a certain base station to user, the signal-to-noise ratio must be greater than or equal to a given value ω.
And solving the maximization of the objective function to obtain a compensated optimal allocation scheme.
The wireless self-organizing network interruption compensation method provided by the invention comprehensively considers the optimization of wireless parameters and the optimization of mechanical parameters, is suitable for various application scenes, adjusts key parameters influencing the service quality of a user and the efficiency of a base station, and is more flexible than single parameter adjustment. The optimization effect is measured by using the user transmission rate, changes caused by optimization can be truly reflected, the services of the users are classified, more important services can be preferentially met, and the service requirements of the users with high priority can be met as much as possible on occasions with high user density or interruption of more base stations.
In one embodiment, before determining, as the compensated allocation scheme, an allocation scheme that maximizes the weighted transmission rates of all the user terminals from among the allocation schemes for serving the user terminals from the plurality of different base stations, the method further includes: determining the signal-to-noise ratio between a base station and a user according to the channel gain between the user and the base station, the downlink transmission power provided by the base station for the user and the total transmission power of the base station; and determining the transmission rate of the user according to the signal-to-noise ratio.
After obtaining the channel gain between the user and the base station, the signal-to-noise ratio between the base station i and the user j can be calculated, and the calculation formula is as follows:
wherein, Pi jRepresents the downlink transmission power, S, provided by the base station i for the user jijIndicating communication between the twoThe relationship is such that,representing the channel gain, P, between the twokThe transmission power of a certain base station is represented by the following calculation formula:
the formula indicates that the transmission power of a certain base station is equal to the sum of the downlink transmission powers received by all the users served by the certain base station.
StatekIndicates the operating state of the base station, N0Is a constant and represents the spectrum density of additive white gaussian noise, and the meaning of the above formula is: the signal-to-noise ratio between a base station i and a user j is equal to the value obtained by multiplying the effective power received by the user by the gain and dividing the effective power transmitted by all other base stations by the sum of Gaussian white noise.
After acquiring the signal-to-noise ratio, the transmission rate can be obtained
Where B is the channel bandwidth.
In one embodiment, before determining the signal-to-noise ratio between the base station and the user according to the channel gain between the user and the base station, the downlink transmission power provided by the base station for the user, and the total transmission power of the base station, the method further includes: respectively determining horizontal antenna gain and vertical antenna gain according to a horizontal azimuth angle and a vertical azimuth angle between a user and a base station; determining the total antenna gain between the base station and the user according to the horizontal antenna gain and the vertical antenna gain; and determining the channel gain between the user and the base station according to the total antenna gain and the user equipment gain.
Key factors affecting base station coverage include dayDown tilt and azimuth of the line, wherein when the antenna is down tiltThe vertical azimuth between base station i and user j is assumed to beThen the calculation formula is:
horizontal azimuth between base station i and user j isThe calculation formula of the horizontal antenna gain is as follows:
wherein, delta3dBRepresenting horizontal half-power lobe width, GmIs a constant.
The vertical azimuth angle between the base station i and the user j isThe calculation formula of the vertical antenna gain is as follows:
wherein ξeAnd SLAvAre all constant, xi3dBVertical half power lobe width.
Obtaining the horizontal azimuth angle between the base station i and the user jAnd vertical azimuthThe total antenna gain between base station i and user j may then be calculatedThe calculation formula is as follows:
obtaining total antenna gainThe channel gain between base station i and user j can then be calculatedThe calculation formula is as follows:
wherein G isuserWhich represents the gain of the user equipment and,represents the path loss between base station i and user j, whereThe calculation formula of (2) is as follows:
wherein f iscRepresenting the carrier frequency and epsilon the excess loss.
In one embodiment, before determining the allocation scheme with the largest weighted transmission rate for all the ues from among the allocation schemes serving ues from the plurality of different base stations as the compensated allocation scheme, the method further includes: determining a coverage radius of each base station; for any two base stations m and n, determining the connection relation between the base stations according to the following formula:
determining that the sum of the number of connections between all base stations in any allocation scheme is greater than a preset threshold;
wherein d ism,nIs the distance between base stations m and n, rm、rmThe coverage radius of base stations m and n, respectively.
That is, there must be a sufficient (preset number) of base stations that are overlapped by the coverage area.
For each base station, there is its coverage radius, and the calculation formula is:
wherein d isiThe farthest service user distance obtained by the path loss formula is represented, and the coverage radius of the base station is equal to the smaller value of the farthest distance corresponding horizontal distance of the service object and the tan value of the height of the base station divided by the downward inclination angle. After the coverage radius of each base station is obtained, the connectivity relationship between any two base stations can be evaluated, as shown in formula (13).
Accordingly, the following constraints can be added when solving equation (3):
i.e. indicating that the number of connections between all base stations needs to be greater than a given value η.
According to the embodiment of the invention, the sum of the number of the connected base stations in any distribution scheme is determined to be larger than the preset threshold value, so that more resources can be ensured to carry out network compensation between the base stations, and the compensation effect is improved.
In one embodiment, the determining, as the compensated allocation scheme, an allocation scheme with the largest weighted transmission rate for all users from among the allocation schemes for serving the user terminals from the plurality of different base stations includes: taking each distribution scheme as a particle of a particle swarm algorithm, and initializing the value, the particle position and the particle speed of each particle; calculating the fitness of each particle by taking the weighted transmission rate of the user as a fitness function, and updating the historical optimal position and the global optimal position of each particle; dividing the particles into advanced particles and common particles according to the fitness, and updating the common particles and the advanced particles; if the fitness of the new position of the advanced particles is lower than that of the position before updating, rolling back to the position before updating, generating a chaotic point list based on the current position by adopting a chaotic mapping mode, and selecting a point with the highest fitness as a new position until the updating of all the particles is completed; repeating the calculation of the fitness of each particle, updating the historical optimal position and the global optimal position of each particle, updating common particles and advanced particles until the iterative process of updating all the particles is completed until the preset iterative times are reached; and selecting the particles with the maximum fitness function value as the distribution scheme after compensation.
The particle swarm optimization belongs to one of evolutionary algorithms, starting from random solutions, an optimal solution is searched through iteration, the quality of the solution is evaluated through fitness, compared with a genetic algorithm, operations of crossing and variation are removed, the global optimization is searched through searching the optimal value searched currently, and the particle swarm optimization algorithm is high in precision and high in convergence speed.
The invention adopts an improved particle swarm optimization algorithm based on chaotic mapping to implement interruption compensation. In order to avoid the algorithm from falling into local optimization, the invention introduces chaotic mapping in the particle position updating. The chaos refers to a random motion state obtained by a deterministic equation, a variable with the chaos state is called a chaos variable, the variable has randomness, ergodicity and regularity, the search can be optimized by utilizing the characteristics of the chaos variable, the local optimization is avoided, and the global search capability of the algorithm is improved.
In the algorithm iteration process, the particles are divided into two types according to the fitness value, wherein one type is an advanced particle, and the other type is a common particle. The advanced particles refer to particles of which the fitness value does not change any more or the change amplitude is small (if the change amplitude is smaller than a preset threshold value or the change amplitude is smaller than a preset proportion) when reaching a certain value in iteration, for common particles, the positions and the speeds are updated and iterated in a conventional mode, for the advanced particles, the positions are updated by a common particle method at first, if the fitness value of a new position is not higher than the current position, the original coordinates are returned, a chaotic point column to be selected is generated in a chaotic mapping mode, a point with the highest fitness is selected as a new coordinate, and the speed of the point does not change any more. The advanced particles search an optimal solution in a local range by a chaotic mapping method, and in an iteration process, the two types of particles are mutually converted and jointly evolved.
According to the idea, the algorithm first initializes the particle swarm, which contains a set of random solutions, with the format Xi＝(x1,x2,...xK) Each solution x in the set of random solutionsiIs a scheme representing the power allocation and the configuration of the downtilt and azimuth for all base stations to the user, assuming K ∈ K, for scheme xkFor example, the content represented is:
when each base station allocates power, it needs to ensure that:
1) the sum of the power distributed by the single base station can not be more than Pi MAX。
2) The power allocated to each user must be guaranteed to be equal to or greater than the gain multiplied by the gain
3) Each base station has a State code StateiIndicating the operating status of the base station and maintaining a service list indicating the subscriber numbers served by the base station, wherein a value of 1 indicates the base stationi serves the corresponding user, and a value of 0 indicates that the base station i does not serve the user, and all users need to be guaranteed to be served in the initial solution set and each iteration process.
4) Each user can only be served by one base station, so if a user has been assigned to a base station, no other base stations provide service to the user.
5) If the status code of a base station is 0, the downtilt, azimuth and service list are all empty.
6) For any base station user pair, its signal-to-noise ratio must be greater than a given value ω.
7) Its coverage radius can be calculated from the service list and the downtilt of the base station and its adjacency to neighboring base stations can be evaluated, where the number of adjacencies must be greater than a given value η.
The above conditions need to be satisfied at all times during the initialization solution set and the iteration process. For each particle, given its initial velocity, Vi＝(v1,v2,...vK) Wherein v iskFor particle xkThe velocity of movement, expressed in the same form as the particle, is as follows:
each particle has a fitness determined by the objective function and is able to know the best location found so far, pbest, and the location x at which it is now locatedkIn addition, all the particles share the position information, so that the best position gbest found by all the particles in the whole group can be known, and the particles determine the next action by the experience of the particles and the best experience in the group.
vk＝ω*vk+c1×rand()×(pbestk-xk)+c2×rand()×(gbest-xk) (17)
The above is an updated formula of the particle velocity,wherein ω vkRepresenting the degree of influence of the velocity in the next step with the velocity of the previous state, w is the inertia factor.
In one embodiment, the updating of the normal particles and the advanced particles includes: determining an inertia factor according to the fitness function and the optimal positions found by all the particles; updating the ordinary particles and the advanced particles according to the inertia factor, the optimal positions found by all the particles and the optimal positions found by history.
The invention adopts an improved particle swarm optimization algorithm based on adaptive weight and chaotic mapping to implement interruption compensation, and in speed updating, the weight w adopted by the traditional particle swarm optimization algorithm is a fixed value and lacks variation.
In the present invention, the inertia factor w is defined as:
where gbest represents the maximum value of the current global fitness. fitkRepresenting the fitness for particle k, the formula is:
wherein, CjI.e. the transmission rate in the model part, and alpha is the weight.
In the conventional particle swarm optimization, c1 and c2 are fixed values respectively indicating the degree of influence of the speed by the maximum value searched by the algorithm and the global maximum value, if c2 is too large in the initial stage of the algorithm, the algorithm tends to the global optimal position too early, so that a local optimal solution is caused, and if c1 is too large in the later stage of the algorithm, the algorithm is difficult to converge, so that c1 should be large in the initial stage and gradually reduced, and c2 should be small in the initial stage and gradually increased in the whole iteration process of the algorithm.
c1×rand()×(pbestk-xk) For self-aware items, a vector pointing from the current point to the best point considered by the particle itself, wherecur represents the current number of iterations, total represents the given total number of iterations, and as the number of iterations increases, c1And will continue to decrease.
c2×rand()×(gbestk-xk) A vector pointing from the current point to the best point in the population for a population-aware item reflects collaborative collaboration and knowledge sharing among particles, whereAs the number of iterations increases, c2Will increase accordingly.
After the velocity of the particle for this iteration is obtained, the position of the particle can be updated, as shown in the following formula:
in summary, the steps of the algorithm can be found as follows:
1) initializing various parameters including total iteration times total, chaos mapping iteration times M and population scale K, and giving an initial population and an initial speed.
2) The fitness of each particle is calculated.
3) The historical best positions pbest for each particle are updated, as well as the global best position gbest.
4) The method comprises the steps of dividing particles into two types according to fitness, namely common particles and advanced particles, updating speed and position of the common particles, trying to update the position of the advanced particles in a common particle mode, rolling back to an original position if the new position fitness is lower than the current position, generating a chaotic point array based on the current position in a chaotic mapping mode, and selecting a point with highest fitness as a new position without changing the speed. In this way the entire population of particles is updated.
5) If the current iteration number cur > v, ending the algorithm and outputting the optimal scheme, otherwise returning to the step 2). As shown in the following table:
the interrupt compensation method of the wireless self-organizing network of the embodiment of the invention adopts an interrupt compensation method of an improved particle swarm algorithm based on self-adaptive weight and chaotic mapping, and comprises the following steps: the current optimal distribution scheme is searched by a heuristic method, the algorithm is prevented from falling into local optimization by adopting a self-adaptive weight and chaotic mapping method, and the optimization effect is ensured.
In one embodiment, the generating of the chaotic point column based on the current position by using the chaotic mapping method includes: tent mapping is carried out according to the particles at the current position, three dimensional parameters of downward inclination angle setting, azimuth angle setting and user power distribution of each particle antenna are mapped to a 0-1 interval according to the following formula:
after iteration for M times, obtaining a chaos sequence
Updating each dimension parameter in the particle k according to the following formula;
wherein [ a ]l,bl]For each dimension of the parameter, xklThe i-dimension parameter of the k-th particle is represented.
The chaos mapping mode adopted by the embodiment of the invention is Tent mapping, and the formula is as follows:
according to Tent mapping, the chaotic point column of the particle k can be obtained through the following steps:
1) particle x is expressed according to equation (21)kThe parameters of the three dimensions in (1) are mapped, the third dimension is a distribution scheme, and the mapping method is the same.
The variables are mapped to the interval 0 to 1 by the above formula.
2) Using equation (21) to convert cxklIterate M times to obtain chaos sequence
3) Each dimension in particle k is updated as in equation (22).
4) The particles x can be obtained through a chaotic sequencekIn the chaos point column after Tent mapping, it should be noted that, because there is a constraint relationship, points that do not meet the constraint need to be filtered and deleted after mapping:
the following describes the wireless ad hoc network interruption compensation apparatus provided by the present invention, and the wireless ad hoc network interruption compensation apparatus described below and the wireless ad hoc network interruption compensation method described above may be referred to in correspondence with each other.
Fig. 2 is a schematic structural diagram of a wireless ad hoc network outage compensation apparatus provided in the present invention, as shown in fig. 2, the wireless ad hoc network outage compensation apparatus includes: an allocation module 201 and a processing module 202. The allocation module 201 is configured to determine, after an interruption in any cell in the target area, allocation schemes for serving the user terminals by a plurality of different base stations according to a plurality of allocation manners in which all the user terminals in the target area are reallocated to each base station in the target area for service, and a plurality of allocation manners in which each base station allocates the downtilt angle of the antenna, the azimuth angle of the antenna, and the power of the served user terminal; the processing module 202 is configured to determine, from the allocation schemes of the plurality of different base stations serving the user terminals, an allocation scheme that maximizes the weighted transmission rate of all the user terminals as a compensated allocation scheme.
In an apparatus embodiment, the processing module 202 is further configured to determine, from among the allocation schemes of the plurality of different base stations serving the user terminals, an allocation scheme that maximizes the weighted transmission rates of all the user terminals, as a compensated allocation scheme before: determining the signal-to-noise ratio between the base station and the user according to the channel gain between the base station and the user, the downlink transmission power provided by the base station for the user and the total transmission power of the base station; and determining the transmission rate of the user according to the signal-to-noise ratio.
In an embodiment of the apparatus, the processing module 202 is further configured to, before determining the signal-to-noise ratio between the base station and the user according to a channel gain between the base station and the user, a downlink transmission power provided by the base station for the user, and a total transmission power of the base station: respectively determining horizontal antenna gain and vertical antenna gain according to a horizontal azimuth angle and a vertical azimuth angle between a user and a base station; determining the total antenna gain between the base station and the user according to the horizontal antenna gain and the vertical antenna gain; and determining the channel gain between the user and the base station according to the total antenna gain and the user equipment gain.
In an apparatus embodiment, the processing module 202 is further configured to determine, from among the allocation schemes of the plurality of different base stations serving the user terminals, an allocation scheme that maximizes the weighted transmission rates of all the user terminals, as a compensated allocation scheme before: determining a coverage radius of each base station; for any two base stations m and n, determining the connection relation between the base stations according to the following formula:
determining that the sum of the number of connections between all base stations in any allocation scheme is greater than a preset threshold;
wherein d ism,nIs the distance between base stations m and n, rm、rmThe coverage radius of base stations m and n, respectively.
In an apparatus embodiment, the processing module 202 is further configured to: taking each distribution scheme as a particle of a particle swarm algorithm, and initializing the value, the particle position and the particle speed of each particle; calculating the fitness of each particle by taking the weighted transmission rate of the user as a fitness function, and updating the historical optimal position and the global optimal position of each particle; dividing the particles into advanced particles and common particles according to the fitness, and updating the common particles and the advanced particles; if the fitness of the updated position of the advanced particles is lower than that of the position before updating, rolling back to the position before updating, generating a chaotic point row based on the current position by adopting a chaotic mapping mode, and selecting a point with the highest fitness as a new position until the updating of all the particles is completed; repeating the calculation of the fitness of each particle, updating the historical optimal position and the global optimal position of each particle, updating common particles and advanced particles until the iterative process of updating all the particles is completed until the preset iterative times are reached; and selecting the particles with the maximum fitness function value as the distribution scheme after compensation.
In an apparatus embodiment, the processing module 202 is further configured to: determining an inertia factor according to the fitness function and the historical optimal position; and updating the common particles and the advanced particles according to the inertia factor, the historical optimal position and the global optimal position.
In an apparatus embodiment, the processing module 202 is further configured to: tent mapping is carried out according to the particles at the current position, three dimensional parameters of the downward inclination angle and the azimuth angle of the antenna in each particle and the power distribution of a user are mapped to a 0-1 interval according to the following formula:
after iteration for M times, obtaining a chaos sequence
Updating each dimension parameter in the particle k according to the following formula;
wherein [ a ]l,bl]For each dimension of the parameter, xklThe i-dimension parameter of the k-th particle is represented.
The device embodiment provided in the embodiments of the present invention is for implementing the above method embodiments, and for details of the process and the details, reference is made to the above method embodiments, which are not described herein again.
The wireless self-organizing network interruption compensation device provided by the embodiment of the invention comprehensively considers the optimization of wireless parameters and the optimization of mechanical parameters, is suitable for various application scenes, adjusts key parameters influencing the service quality of a user and the effect of a base station, and is more flexible than single parameter adjustment. The optimization effect is measured by using the user transmission rate, changes caused by optimization can be truly reflected, the services of the users are classified, more important services can be preferentially met, and the service requirements of the users with high priority can be met as much as possible on occasions with high user density or interruption of more base stations.
Fig. 3 is a schematic structural diagram of an electronic device provided in the present invention, and as shown in fig. 3, the electronic device may include: a processor (processor)301, a communication Interface (communication Interface)302, a memory (memory)303 and a communication bus 304, wherein the processor 301, the communication Interface 302 and the memory 303 complete communication with each other through the communication bus 304. Processor 301 may invoke logic instructions in memory 303 to perform a wireless ad hoc network outage compensation method comprising: after any cell in the target area is interrupted, determining a distribution scheme of a plurality of different base stations for serving user terminals according to a plurality of distribution modes of all user terminals in the target area redistributed to each base station in the target area for serving and a plurality of distribution modes of each base station for antenna downward inclination angles, antenna azimuth angles and power of the served user terminals; determining an allocation scheme that maximizes the weighted transmission rates of all user terminals from the plurality of different allocation schemes as a compensated allocation scheme.
In addition, the logic instructions in the memory 303 may be implemented in the form of software functional units and stored in a computer readable storage medium when the logic instructions are sold or used as independent products. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.
In another aspect, the present invention also provides a computer program product, the computer program product comprising a computer program stored on a non-transitory computer-readable storage medium, the computer program comprising program instructions, which when executed by a computer, enable the computer to perform the method for compensating for interruption of a wireless ad hoc network provided by the above methods, the method comprising: after any cell in the target area is interrupted, determining a distribution scheme of a plurality of different base stations for serving user terminals according to a plurality of distribution modes of all user terminals in the target area redistributed to each base station in the target area for serving and a plurality of distribution modes of each base station for antenna downward inclination angles, antenna azimuth angles and power of the served user terminals; determining an allocation scheme that maximizes the weighted transmission rates of all user terminals from among the allocation schemes of the plurality of different base station serving user terminals as a compensated allocation scheme.
In yet another aspect, the present invention also provides a non-transitory computer-readable storage medium, on which a computer program is stored, the computer program being implemented by a processor to perform the method for compensating for interruption of a wireless ad hoc network provided in the foregoing embodiments, the method including: after any cell in the target area is interrupted, determining a distribution scheme of a plurality of different base stations for serving user terminals according to a plurality of distribution modes of all user terminals in the target area redistributed to each base station in the target area for serving and a plurality of distribution modes of each base station for antenna downward inclination angles, antenna azimuth angles and power of the served user terminals; determining an allocation scheme that maximizes the weighted transmission rates of all user terminals from among the allocation schemes of the plurality of different base station serving user terminals as a compensated allocation scheme.
The above-described embodiments of the apparatus are merely illustrative, and the units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.
Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware. With this understanding in mind, the above-described technical solutions may be embodied in the form of a software product, which can be stored in a computer-readable storage medium such as ROM/RAM, magnetic disk, optical disk, etc., and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the methods described in the embodiments or some parts of the embodiments.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.