面向卫星物联网的柔性多址接入技术  

Flexible Multiple Access Technology for Satellite Internet of Things

作　　者：庞明亮 王朝炜[1,3] 吴彤 陈佳彬 黄赛 江帆 张君毅 PANG Mingliang;WANG Chaowei;WU Tong;CHEN Jiabin;HUANG Sai;JIANG Fan;ZHANG Junyi(School of Electronic Engineering,Beijing University of Posts and Telecommunications,Beijing 100876,China;China Satellite Network Application Co.,Ltd.,Beijing 100029,China;Key Laboratory of Universal Wireless Communications,Ministry of Education,Beijing 100876,China;School of Communication and Information Engineering,Xi’an University of Posts and Telecommunications,Xi’an 710121,China)

机构地区：[1]北京邮电大学电子工程学院,北京100876 [2]中国星网网络应用研究院有限公司,北京100029 [3]泛网无线通信教育部重点实验室,北京100876 [4]西安邮电大学通信与信息工程学院,西安710121

出　　处：《电子与信息学报》2024年第6期2497-2505,共9页Journal of Electronics & Information Technology

基　　金：重庆市自然科学基金创新发展联合基金(CSTB2023NSCQ-LZX0118);北京邮电大学博士生创新基金(CX2023139)。

摘　　要：基于时隙ALOHA(S-ALOHA)的免授权上行随机接入能够显著降低卫星物联网(IoT)中的接入时延和复杂度。然而,随着物联网用户数量的增加,S-ALOHA碰撞概率会显著增加,从而影响系统性能。该文针对卫星物联网中存在海量设备上行接入的场景,专注于研究物联网终端的功率资源控制,以实现最大化系统和速率的目标。具体而言,该文提出基于S-ALOHA的柔性多址接入。当系统中存在碰撞时,采用非正交多址技术进行传输,从而避免了用户信息反复重传的问题,降低了传输时延。为了在终端功率受限的情况下实现系统和速率的最大化,该文将序列决策问题建模为马尔可夫决策过程,并采用优势演员-评论家算法(A2C)进行求解。仿真结果表明,所提出的柔性多址接入技术能够在海量物联网终端的场景下有效保证终端的接入成功率。同时,基于A2C的资源分配算法相较于传统的资源分配算法表现更为优越。Access latency and complexity in the satellite Internet of Things(IoT)are significantly reduced by the grant-free uplink random access based on Slotted ALOHA(S-ALOHA).However,with the increase of the number of IoT users,the collision probability of S-ALOHA is markedly increased,thereby impacting the performance of the system.This paper addresses the scenario of massive device uplink access in satellite IoT,focusing on the investigation of power resource control for IoT terminals to achieve maximization of system rate.A flexible multiple access scheme based on S-ALOHA is proposed.In the presence of collisions in the system,transmission is carried out using non-orthogonal multiple access technology,which mitigates the issue of repeated transmission of user information and reduces transmission latency.The sequential decision problem of maximizing system rate under the constraint of terminal power is modeled as a Markov process,and the Advantage Actor-Critic(A2C)method is employed to solve it.The simulation results indicate that the success rate of terminal access in scenarios with a massive number of IoT terminals is effectively ensured by the proposed flexible multiple access technology.Additionally,the resource allocation algorithm based on A2C is shown to outperform traditional resource allocation algorithms.

关 键 词：卫星物联网 柔性多址接入 资源分配 A2C 

分 类 号：TN927[电子电信—通信与信息系统]