卫星无小区大规模 MIMO 上行链路中用于能量效率最大化的联合负载均衡与发射功率控制
Joint Load Balancing and Transmit Power Control for Energy Efficiency Maximization in the Satellite-Cell-Free Massive MIMO Uplink
AI总结：
研究混合卫星无小区大规模 MIMO 系统，利用最大比合并推导上行遍历吞吐量闭式表达式，制定能量效率优化问题，开发改进差分进化框架，有效提升了能量效率和网络吞吐量，为大规模场景提供关联准则。
AI中文摘要：
非地面与地面基础设施的无缝集成是下一代无线网络实现普遍连接的关键推动因素。本文研究了一种混合卫星无小区大规模 MIMO 系统，其中多颗低地球轨道卫星在实际不完美信道状态信息和实际用户关联约束下，与地面接入点共同为用户服务。首先利用最大比合并推导了在空间相关莱斯衰落信道上传输的上行遍历吞吐量的闭式表达式，揭示了用户 - 卫星和用户 - 接入点关联模式对频谱效率和速率公平性的影响。接着制定了联合用户关联和功率控制下的能量效率优化问题，因用户关联变量的二元性该问题本质上是 NP 难的，故开发了改进的差分进化框架在多项式时间内有效探索可行解。数值结果验证了分析并表明所提混合方案显著提高了能量效率和网络吞吐量，为大规模场景提供了实用的用户 - 卫星 - 接入点关联准则，实现了可扩展的性能提升。
英文摘要：
The seamless integration of non-terrestrial and terrestrial infrastructures is a key enabler for ubiquitous connectivity in next-generation (NG) wireless networks. We investigate a hybrid satellite-cell-free Massive MIMO system, where multiple low-Earth-orbit (LEO) satellites jointly serve users in unison with terrestrial access points (APs) under realistic imperfect channel state information and practical user association constraints. We first derive closed-form expressions of the uplink ergodic throughput by exploiting maximum ratio combining (MRC) for transmission over spatially correlated Rician fading channels. Our analysis reveals the characteristic impact of both user-satellite and user-AP association patterns on both the spectral efficiency and rate-fairness achieved. We then formulate an energy efficiency optimization problem under joint user association and power control. Since the problems are inherently NP-hard due to the binary nature of the user-association variables, we develop an improved Differential Evolution (IDE) framework that efficiently explores the feasible solutions in polynomial time. Numerical results validate our analysis and show that the proposed hybrid scheme substantially improves energy efficiency and network throughput. For large-scale scenarios, the DE framework provides practical user-satellite-AP association guidelines, enabling scalable performance gains.
