基于非稳态MAB的LEO卫星跳波束时隙分配算法

Time-slot allocation algorithm for LEO satellite beam hopping based on non-stationary MAB

针对低地球轨道(LEO)卫星系统中的跳波束资源分配算法不能适应小区业务动态变化等问题,提出了一种基于非稳态多臂赌博机(MAB)的LEO卫星跳波束时隙分配算法。首先,以系统二阶差分容量最小化为优化目标,建立了时隙分配和波束等级匹配的联合优化问题。其次,由于该问题非凸且难以直接求解,基于有效小区和有效关键小区的概念提出波束等级组合方案生成算法,从而生成所有可能的波束等级组合方案。接下来,提出了基于非稳态MAB模型的动态时隙分配方案,在最优波束等级组合方案下完成时隙分配与波束等级匹配的联合优化。最后,计算机仿真结果表明,所提算法在多种小区业务分布的情况下,系统平均冗余度均不超过20%;相比于其他对比方案,所提算法在保持较高的系统吞吐量的同时,还可以将波束平均重访时间控制在300 ms左右。

Aiming at the problem of inadequate adaptation to dynamic changes in cell services in the resource allocation algorithm for hopping beams in low earth orbit(LEO)satellite systems,a time-slot allocation algorithm for LEO satellite beam hopping based on a non-stationary multi-armed bandit(MAB)was proposed.Firstly,the joint optimization problem of slot allocation and beam grading matching was established,with the minimization of the system’s second-order differential capacity as the optimization objective.Secondly,due to the non-convexity and difficulty in direct solution of this problem,a beam grading combination scheme generation algorithm was proposed based on the concept of effective cells and effective critical cells,which generated all possible beam grading combination schemes.Next,a dynamic slot allocation scheme based on the non-stationary MAB model was proposed,and joint optimization of slot allocation and beam grading matching was completed under the optimal beam grading combination scheme.Finally,the computer simulation results show that the average redundancy of the proposed algorithm is less than 20%in the case of multiple cell service distributions.In addition,compared with other schemes,the proposed algorithm can control the average beam revisit time to about 300 ms while maintaining high system throughput.