CN-122001443-A - Large-scale MIMO low-orbit satellite communication user scheduling method and system based on simulated bifurcation algorithm

CN122001443ACN 122001443 ACN122001443 ACN 122001443ACN-122001443-A

Abstract

The invention provides a large-scale MIMO low-orbit satellite communication user scheduling method and system based on a simulated bifurcation algorithm. The satellite base station acquires the statistical channel state information of each user, and adopts a low-complexity maximum ratio combining receiver to carry out uplink user scheduling by taking the maximum traversal and the maximum speed as targets under the condition of meeting the resource number requirements of each user. In order to facilitate solving, the original user scheduling problem is approximated to an equality constraint quadratic combination optimization problem, the equality constraint problem is further converted into an unconstrained problem by using an augmented Lagrangian function, and updating of Lagrangian multipliers and penalty factors is embedded into a simulation bifurcation algorithm to solve the unconstrained quadratic combination optimization problem. The invention can obtain a better balance between complexity and performance, and greatly improves the uplink and speed of the large-scale MIMO low-orbit satellite communication system on the basis of guaranteeing the number of resources required by each user.

Inventors

LU ANAN
ZHAO LISHUAI
SUN CHEN
GAO XIQI

Assignees

东南大学

Dates

Publication Date: 20260508
Application Date: 20260108

Claims (10)

1. The large-scale MIMO low-orbit satellite communication user scheduling method based on the simulated bifurcation algorithm is characterized by comprising the following steps of: acquiring statistical channel state information of each user; Establishing an equality constraint quadratic combination optimization problem of user scheduling by using the statistical channel state information of each user, wherein the optimization variables comprise a user scheduling matrix, the equality constraint comprises a constraint of the number of resources required by each user, the optimization target is constructed based on maximized traversal and speed, the optimization variables are decoupled from a logarithmic function by introducing auxiliary variables, and the problem is further converted into the equality constraint quadratic combination optimization problem by bringing the optimal value, the design weight coefficient and the approximate signal-to-interference-and-noise ratio of the auxiliary variables; the method comprises the steps of establishing an equation constraint quadratic combination optimization problem by means of a simulation bifurcation algorithm to obtain a user scheduling matrix, converting the equation constraint quadratic combination optimization problem into an unconstrained problem by means of an augmented Lagrange function, solving the unconstrained problem by means of the simulation bifurcation algorithm, embedding updating of Lagrange multipliers and penalty factors corresponding to the equation constraints into the simulation bifurcation algorithm, and updating values of the Lagrange multipliers and the penalty factors according to preset frequencies.
2. The method for scheduling large-scale MIMO low-orbit satellite communication users based on the analog bifurcation algorithm according to claim 1, wherein the satellite base station obtains statistical channel state information of each user by using the received pilot frequency or according to the base station and the user position, and the statistical channel state information includes an array response vector of each user and channel gain between each user and the satellite on each resource.
3. The method for scheduling large-scale MIMO low-orbit satellite communication users based on the analog bifurcation algorithm according to claim 1, wherein the satellite base station uses a maximum ratio combining receiver based on statistical channel state information to combine resources Upper user Uplink reachable traversal rate Approximately as Wherein , Representing a user Occupying resources Otherwise , Representing the transmit power of each user, Which represents the power of the noise and, Is a resource Upper user Rice variable corresponding to channel gain Is a mean square value of (c) and, , 、 Respectively represent users 、 Is used to determine the array response vector of (a), Representing the conjugate transpose.
4. The method for massive MIMO low-orbit satellite communication user schedule based on the simulated bifurcation algorithm according to claim 3, wherein said decoupling the optimization variable from the logarithmic function by introducing the auxiliary variable comprises decoupling the optimization objective Equivalent to Wherein And The number of users and the number of resources are respectively, In order to introduce the auxiliary variable(s), , Representing the user scheduling matrix, wherein after substituting the optimal value of the auxiliary variable, the optimization target is simplified into 。
5. The method for scheduling large-scale MIMO low-orbit satellite communication users based on the simulated bifurcation algorithm according to claim 1, wherein the equation constraint quadratic combination optimization problem is that ; Wherein the method comprises the steps of And The number of users and the number of resources are respectively, Representing a user scheduling matrix of the user, Representing a user Occupying resources Otherwise , Representing a user The number of resources required is the number of resources, A set of users is represented and, , , Representing the transmit power of each user, Which represents the power of the noise and, Is a resource Upper user Rice variable corresponding to channel gain Is a mean square value of (c) and, , 、 Respectively represent users 、 Is used to determine the array response vector of (a), Representing the conjugate transpose.
6. The method for scheduling large-scale MIMO low-orbit satellite communication users based on the simulated bifurcation algorithm according to claim 1, wherein the augmented lagrangian function is Wherein , , , , Representation and representation The item of interest is a non-related item, The transpose is represented by the number, Representing a user Occupying resources Otherwise , And The number of users and the number of resources are respectively, , , A diagonal matrix is represented and, , , , Representing the transmit power of each user, Which represents the power of the noise and, Is a resource Upper user Rice variable corresponding to channel gain Is a mean square value of (c) and, , 、 Respectively represent users 、 Is used to determine the array response vector of (a), Represents the conjugate transpose of the object, , And Each representing 1 of each element Dimension vector The vector of dimensions is used to determine, The product of the Hadamard is represented, , Representing dimension as Is arranged in a matrix of units of (a), , , , And Respectively represent the first The equations constrain the corresponding lagrangian multipliers and penalty factors, Representing a user The number of resources required.
7. The method for massive MIMO low-orbit satellite communication user scheduling based on the simulated bifurcation algorithm according to claim 1, wherein the step of solving the established equality constraint quadratic combination optimization problem using the simulated bifurcation algorithm comprises: a) Introducing Lagrangian multipliers and penalty factors according to the equality constraint of each user, and performing optimization variable value range conversion to obtain an augmented Lagrangian function; b) Initializing the position and momentum of each spin to cause ; C) Order the Wherein And The current iteration number and the maximum iteration number of the analog bifurcation algorithm are respectively represented, Representing the analog bifurcation algorithm No. 1 The key parameter for controlling the update of the momentum is taken as a value in the next iteration, and the position and the momentum of each spin are updated to make ; D) If it is Then the Lagrangian multiplier and penalty factor are updated, where A positive integer representing the update frequency of the control Lagrangian multiplier and penalty factor in the analog bifurcation algorithm; e) If it is And c) jumping to the step c), otherwise outputting the sign function value of the position.
8. A massive MIMO low-orbit satellite communication user scheduling system based on a simulated bifurcation algorithm, configured to implement a massive MIMO low-orbit satellite communication user scheduling method based on a simulated bifurcation algorithm according to any one of claims 1-7, comprising: the user scheduling problem constructing and converting module is used for acquiring the statistical channel state information of each user and establishing an equality constraint quadratic form combination optimization problem of user scheduling by utilizing the statistical channel state information of each user; And the user scheduling problem solving module is used for solving the established equation constraint quadratic combination optimization problem by using the simulated bifurcation algorithm to obtain a user scheduling matrix.
9. An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, characterized in that the computer program when executed by the processor implements the steps of the massive MIMO low-orbit satellite communication user scheduling method based on the analog bifurcation algorithm according to any one of claims 1-7.
10. A computer program product comprising a computer program, characterized in that the computer program when executed by a processor implements the steps of the massive MIMO low-orbit satellite communication user scheduling method based on the simulated bifurcation algorithm according to any one of claims 1-7.

Description

Large-scale MIMO low-orbit satellite communication user scheduling method and system based on simulated bifurcation algorithm Technical Field The invention belongs to the technical field of communication, and relates to a large-scale MIMO low-orbit satellite communication user scheduling method and system based on a simulated bifurcation algorithm. Background The rapid development of low-orbit satellite communication systems makes it possible to realize stable and wide-area communication connection in areas where the ground wireless network is difficult to deploy or cover with high costs, such as ocean, desert, high altitude, remote mountain areas and the like. With the increasing demands of the Internet of things, emergency communication, global Internet access and the like, the realization of global seamless global coverage has become an important target of wireless communication evolution, and the key position of low-orbit satellite communication in the future space-earth integrated network is further highlighted. In order to cope with challenges of access and high-rate data transmission of mass user equipment in the future, introducing a large-scale Multiple-Input Multiple-Output (MIMO) technology into a low-orbit satellite communication system has become a key research direction for improving spectrum efficiency. The large-scale antenna array can significantly improve the degree of freedom and anti-interference capability of the system through beam forming and spatial multiplexing, but the actual performance of the large-scale antenna array is highly dependent on the channel characteristics among users, in particular the channel correlation. Under the scene of high correlation, the interference among users is aggravated, which leads to the decrease of the space multiplexing gain and seriously affects the throughput of the system. Therefore, in a large-scale MIMO low-orbit satellite communication system, how to select a subset of users with proper channel conditions and small mutual interference from many users for simultaneous service through effective user scheduling is critical to maximizing the throughput of the system and guaranteeing the service quality (Quality of Service, qoS) of the users, and is also one of the core problems in system design and optimization. The existing user scheduling method mainly comprises an exhaustion method, a greedy selection method, a genetic algorithm and the like. The exhaustive method can ensure that a globally optimal scheduling scheme is found by traversing all possible user combinations, however, the computational complexity of the scheduling scheme increases exponentially with the number of users, and the scheduling scheme is difficult to be applied when an actual system, particularly the user scale is large, and is generally only used for theoretical verification or performance benchmark comparison of small-scale scenes. The greedy selection method sequentially considers the interference of the current scheduling user to the scheduled user and distributes the user to the resource which maximizes the overall performance gain, and the calculation complexity is remarkably reduced, but each step is only based on the local optimal decision, so that the adjustment cannot be traced, the finally obtained solution is often in local optimal, the scheduling quality cannot be ensured, and the performance is obviously reduced in the scene of complex inter-user interference structure. Intelligent optimization algorithms such as genetic algorithm and the like define fitness function evaluation scheduling schemes by simulating natural evolution process, and iterate and evolve population by means of operations such as selection, crossing, variation and the like. The method can explore global characteristics of a solution space to a certain extent, but because performance evaluation needs to be carried out on a large number of individuals in a population in each iteration, the computational complexity is generally higher than that of a greedy selection method, the quality of the solution still depends on parameter setting and iteration times seriously, and theoretical performance guarantee cannot be provided. Therefore, how to design a scheduling method that can better trade-off complexity and performance in a massive MIMO low-orbit satellite communication system is of great importance. Disclosure of Invention Aiming at a large-scale MIMO low-orbit satellite communication system, the invention provides a large-scale MIMO low-orbit satellite communication user scheduling method and system based on a simulation bifurcation algorithm, aiming at improving traversal and speed under the constraint of meeting the requirement of the number of resources of each user, and can better realize the balance between complexity and performance. In order to achieve the above purpose, in a first aspect, the present invention provides a large-scale MIMO low-orbit satellite communication user sche