基于可重构智能表面（RIS）发射机的MIMO系统中服务质量约束下的功率最小化

中文摘要 AI 辅助

本研究探讨采用相移键控（PSK）调制、以可重构智能表面（RIS）作为发射机的虚拟多用户多输入多输出（MU-MIMO）系统，聚焦于在满足服务质量（QoS）约束的前提下最小化发射功率，同时解决相关计算复杂度问题。研究采用离散相移RIS模型，将功率最小化问题分为两种场景建模：一是针对四相相移键控（QPSK）用户数据，采用符号差错概率（SEP）作为QoS准则；二是针对一般M阶相移键控（M-PSK）调制，采用联合边界符号差错概率（UBSEP）定义QoS约束。基于上述建模，提出部分分支定界（PBB）方法，该方法相比全分支定界（FBB）方法可实现更优的复杂度权衡。针对高分辨率RIS这一特殊情况，将离散相移集合近似为连续对应集合，从而将原问题重构为斜流形上的约束优化问题，利用所提二分法求解可降低计算复杂度。数值结果表明，所提方法在不同SEP要求下均能有效最小化发射功率，且能实现功率效率与计算复杂度间的平衡。

英文摘要

This study investigates a virtual multiuser multiple-input multiple-output (MU-MIMO) system with PSK modulation, realized with a reconfigurable intelligent surface (RIS)-based transmitter. The study focuses on minimizing transmit power under quality-of-service (QoS) constraints while addressing the associated computational complexity. A discrete phase-shift RIS model is considered, and the power minimization problem is formulated in two scenarios. First, for QPSK user data, the symbol-error probability (SEP) is adopted as the QoS criterion. Second, for general $M$-PSK modulation, the union-bound SEP (UBSEP) is used to define the QoS constraints. Based on the considered formulations, a partial branch-and-bound (PBB) approach is developed, which improves on full branch-and-bound (FBB) methods in the sense of allowing for favorable complexity performance trade-offs. For the special case of high-resolution RIS, the discrete phase-shift set is approximated by its continuous counterpart, enabling the reformulation of the original problems as constrained optimizations on an oblique manifold, which are solved with reduced computational complexity with the proposed bisection method. Numerical results demonstrate the effectiveness of the proposed approaches in minimizing the transmit power for different SEP requirements and showcase the balance between power efficiency and computational complexity

补充信息

DOI

10.1109/TCOMM.2025.3621247