Joint optimization of user association and resource allocation in cache-enabled terrestrial-satellite integrating network

作     者：Shuang NI Junyu LIU Min SHENG Jiandong LI Xiaona ZHAO Shuang NI;Junyu LIU;Min SHENG;Jiandong LI;Xiaona ZHAO

作者机构：State Key Laboratory of Integrated Service NetworksXidian University 

出 版 物：《Science China(Information Sciences)》 (中国科学:信息科学(英文版))

年 卷 期：2021年第64卷第8期

页      面：90-103页

核心收录：

学科分类：0810[工学-信息与通信工程] 0808[工学-电气工程] 08[工学] 0804[工学-仪器科学与技术] 080402[工学-测试计量技术及仪器] 0812[工学-计算机科学与技术（可授工学、理学学位）] 

基　　金：supported in part by National Natural Science Foundation of China (Grant Nos. 61725103, 61701363, 61931005, U19B2025) Young Elite Scientists Sponsorship Program by CAST Fundamental Research Funds for the Central Universities 

主　　题：terrestrial-satellite integrating network content caching user association resource allocation satellite backhaul 

摘      要：Although low earth orbit(LEO) satellites can provide high-capacity backhaul to serve the terrestrial network, the performance of terrestrial-satellite communication systems is critically influenced by the coupling of user association and resource allocation in this integrating system, where user association includes small-cell base station(SBS)-user association and SBS-satellite association. In this work, we consider a cache-enabled terrestrial-satellite integrating network, in which LEO satellites provide backhaul for cacheenabled SBSs to serve ground users. Targeting at maximizing the downlink sum rate of the system and the number of accessed ground users, we formulate an optimization problem where user association and resource allocation of both terrestrial and satellite networks are joint optimized. Owing to the coupling relationship and integer programming nature of this optimization problem, we use Lagrangian relaxation to decouple and decompose it into two subproblems. We propose a user-division matching(UDM) algorithm by dividing all users into multiple user groups, which skillfully solves the first subproblem with multi-objectives. Afterward,to depict the nature of multi-connectivity sufficiently, the second subproblem is converted into a many-toone matching game and solved by a modified Gale-Shapely(MGS) algorithm, which is highly efficient for different satellite constellations. Simulation results demonstrate the proposed algorithms can significantly improve the downlink sum rate of the system by 28.5–120.7 compared to the benchmark algorithms in the typical settings and balance the tradeoff between the downlink sum rate of the system and the number of accessed ground users. Moreover, it also shows that 1% system performance loss can be obtained by the proposed method compared to the optimal solution.