AI 中文总结
研究毫米波大规模 MIMO 混合波束赋形中 QoS 感知问题，通过基带波束赋形减轻 CSI 不确定性，利用有效信道不确定性区域及割集法迭代方案控制 RF 波束形成器，检测消除不可行数据流，大量仿真验证了方法的有效性。
AI 中文摘要
在毫米波频段，支持每个流的服务质量（QoS）的混合波束赋形（HB）在 5G/6G 网络中不可或缺。HB 包含基带和射频（RF）波束赋形，需要无误差的信道状态信息（CSI），但实际中 CSI 存在误差。因此，需要高效、可行、稳健且具备 QoS 感知的 HB。为此，通过基带波束赋形减轻 CSI 不确定性，并利用信道特征向量估计来控制 RF 波束形成器。考虑有效信道的不确定性区域，因其小于信道本身的不确定性区域，满足 QoS 约束所需发射功率更低。还检测并消除不可行数据流。基于割集法的基带波束赋形迭代方案满足每个流的均方误差（MSE）约束，考虑有限数量的约束而非无限多个。在低复杂度方案中，推导了检查每个流可行性的简单充分条件，在基带预编码器处对有效信道进行对角化，并在基带组合器处使用最小 MSE 合并。大量仿真验证了公式和理论推导。
英文摘要
Hybrid beamforming (HB) with quality-of-service (QoS) provisioning per stream in millimeter waves is indispensable in 5G/6G networks. HB includes baseband and radio frequency (RF) beamforming, and requires error-free channel state information (CSI), which is erroneous in practice. So there is a need for efficient, feasible, robust, and QoS-aware HB. To achieve this, we mitigate CSI uncertainty via baseband beamforming, and we steer the RF beamformer by using the estimates of the channel's eigenvectors. In doing so, we consider the effective channel's uncertainty region instead of the uncertainty region of the channel itself, as the former is smaller than the latter, requiring less transmit power to satisfy the QoS constraint. We also detect and eliminate the infeasible data streams. Our iterative scheme (which is based on the cutting-set method) for baseband beamforming satisfies the mean-squared error (MSE) constraint per stream, where a limited number of constraints are considered instead of infinitely many constraints. In our low-complexity scheme, we derive a simple sufficient condition to check the feasibility of each stream, we diagonalize the effective channel at the baseband precoder, and we use minimum MSE combining at the baseband combiner. Extensive simulations validate our formulations and theoretical derivations.
Comments14 pages, 10 figures, 46 references, journal paper published in IEEE TWC
Journal refIEEE Transactions on Wireless Communications 23, no. 2 (2023): 1520-1534
