有限码长域下针对多用户大规模MIMO系统速率优化的高效功率分配算法  

Efficient Power Allocation Algorithm for Throughput Optimization of Multi-User Massive MIMO Systems in Finite Blocklength Regime

作　　者：胡钰林 肖志成 徐浩 HU Yulin;XIAO Zhicheng;XU Hao(Electronic Information School,Wuhan University,Wuhan 430000,China)

机构地区：[1]武汉大学电子信息学院,武汉430000

出　　处：《电子与信息学报》2025年第1期35-47,共13页Journal of Electronics & Information Technology

基　　金：国家重点研发计划(2023YFE0206600)。

摘　　要：第六代(6G)移动通信网络需要为大规模节点提供高可靠低时延通信(URLLC)服务。为此,该文针对多用户大规模多输入多输出(MIMO)技术辅助的URLLC下行通信场景,基于有限码长(FBL)域理论表征系统性能,以用户速率公平性为目标,提出一种高效的功率分配算法。具体而言,该文首先针对传统MIMO中基于全局奇异值分解(SVD)的线性预编码方案复杂度高、不能兼顾用户公平性等问题,设计基于局部SVD的预编码方案,以相对较低的复杂度实现对MIMO用户间干扰和用户内干扰的有效抑制。其次,该文以功率分配因子为优化变量、以最大化最小用户速率(MMR)为目标构建优化问题。为解决所构建的高维变量耦合非凸问题,该文通过引入辅助变量、分段McCormick包络将目标函数中香农容量相关项凸松弛处理,实现MMR问题重构。进而该文提出基于连续凸近似(SCA)的优化算法有效求解MMR问题。仿真结果验证了所提优化算法的收敛性与准确性,同时也表明所提优化方案相比于现有方案在系统MMR性能和鲁棒性上均具有优势。Objective The 6th Generation(6G)mobile communication network aims to provide Ultra-Reliable and Low Latency Communication(URLLC)services to a large number of nodes.To support URLLC for massive users,Multiple-In-Multiple-Out(MIMO)technology has become a key enabler for improving system performance in 6G.However,URLLC systems typically operate with Finite BlockLength(FBL)codes,which pose unique challenges for resource allocation design due to their deviation from traditional methods in the infinite blocklength regime.Although prior studies have explored resource allocation strategies for MIMO-assisted URLLC,power allocation design that considers user fairness remains unresolved.This paper proposes an efficient power allocation algorithm for multi-user MIMO systems in the FBL regime,addressing the issue of user fairness.Methods This study investigates the MIMO-assisted URLLC downlink communication scenario.The system performance is first characterized based on FBL theory,revealing the achievable rate of MIMO downlink users,which introduces significant nonconvexity compared to the infinite blocklength regime.Given the base station's limited power resources,setting system throughput as the optimization objective fails to ensure user fairness.To address this,a Maximum Minimum Rate(MMR)optimization problem is formulated,with power allocation factors as the optimization variables,subject to a total power constraint.The formulated problem is highly nonconvex due to the nonconvex terms in the objective function.To develop an efficient power allocation design for the MMR problem,a low-complexity precoding strategy is first proposed to mitigate both inter-user and intra-user interference.This precoding strategy,based on the local Singular Value Decomposition(SVD)method,reduces complexity compared with the traditional global SVD precoding strategy and effectively suppresses interference.To address the nonconvexity introduced by the Shannon capacity and channel dispersion terms in the objective function,convex relaxation and a

关 键 词：超可靠低时延通信(URLLC) 多用户MIMO 有限码长(FBL) 连续凸近似(SCA) 

分 类 号：TN929.5[电子电信—通信与信息系统]