论文标题
宽带子THZ混合质体系统中的真实时延迟约束下的关节延迟相编码
Joint Delay-Phase Precoding Under True-Time Delay Constraints in Wideband Sub-THz Hybrid Massive MIMO Systems
论文作者
论文摘要
在宽带子terahertz（sub-thz）中，大量多输入多输出（MIMO）通信系统，横梁斜视效应表现为阵列增益中的实质性降解。为了减轻上述梁的斜视效果，已经提出了利用真实时间延迟（TTD）和相位变速器（PS）的混合编码方法。但是，现有方法在TTD设备可以生成任何所需的时间延迟值的假设下运行。这些方法随后在固定PS预编码器时设计了TTD预编码器。这项工作为关节TTD和PS预编码器设计提供了一个新颖的优化框架，其中包含了每个TTD设备的逼真时间延迟约束。与以前的方法不同，我们的框架不依赖于无限的时间延迟假设，而是共同优化TTD和PS值以应对实际限制。此外，在我们提出的框架的上下文中，我们数学确定了必须实现预定目标阵列增益的最小TTD设备数量。仿真确认所提出的方法表现出性能提高，保证阵列增益并实现计算效率。
In wideband sub-Terahertz (sub-THz) massive multiple-input multiple-output (MIMO) communication systems, the beam squint effect manifests as a substantial degradation in array gain. To mitigate the aforementioned beam squint effect, a hybrid precoding approach leveraging both true-time delay (TTD) and phase shifters (PS) has been proposed. However, existing methods operate under the assumption that the TTD device can generate any desired time delay value. These methods subsequently design the TTD precoder while fixing the PS precoder. This work presents a novel optimization framework for the joint TTD and PS precoder design, incorporating realistic time delay constraints for each TTD device. Unlike previous methods, our framework does not rely on the unbounded time delay assumption and optimizes the TTD and PS values jointly to cope with the practical limitations. Furthermore, within the context of our proposed framework, we mathematically determine the minimum number of TTD devices necessitated to achieve a predetermined target array gain. Simulations confirm the proposed approach exhibits performance improvement, guarantees array gain, and achieves computational efficiency.
