论文标题
基于开关的混合横梁成形收发器设计，用于宽带通信与横梁斜视
Switch-based Hybrid Beamforming Transceiver Design for Wideband Communications with Beam Squint
论文作者
论文摘要
基于频率独立相位变速器（PS-HBF）的杂交波束形成（HBF）收发器体系结构对相位和物理方向敏感，其能力有限，无法补偿梁斜视的有害影响。与PSS相比，开关是独立的，功率/成本效率更高的事实，我们考虑了本文中宽带大规模多输入多输出系统的基于开关的HBF（SW-HBF）。我们首先得出了梁斜视比的封闭式表达，并比较了SW-HBF和PS-HBF架构的预期阵列的收益。结果表明，SW-HBF对梁的斜视效果更强大。然后，我们专注于SW-HBF设计，以最大程度地提高单用户和多源系统中的光谱效率（SE），这些系统都是非Convex混合构成问题。对于前者，通过将禁忌搜索（TS）方法和预测的梯度上升（PGA）组合，我们提出了一种有效的启发式PGA-TS算法来设计模拟波束形式，而数字算法则可以接收封闭形式的解决方案。对于后者，我们基于分数编程和PGA-TS方法开发了两步算法。模拟表明，根据Terahertz通信系统中的SE和能源效率，所提出的SW-HBF方案是有效的，并且可以胜过基于PS的HBF架构。
Hybrid beamforming (HBF) transceiver architectures based on frequency-independent phase shifters (PS-HBF) are sensitive to the phases and physical directions with limited capability to compensate for the detrimental effects of the beam squint. Motivated by the fact that switches are phase-independent and more power/cost efficient than PSs, we consider the switch-based HBF (SW-HBF) for wideband large-scale multiple-input multiple-output systems in this paper. We first derive a closed-form expression of the beam squint ratio and compare the expected array gains of both SW-HBF and PS-HBF architectures. The results show that SW-HBF is more robust to the beam squint effect. We then focus on the SW-HBF designs to maximize the spectral efficiency (SE) in both single-user and multiuser systems, which are both non-convex mixed-integer problems. For the former, by combining the tabu search (TS) method and projected gradient ascend (PGA), we propose an efficient heuristic PGA-TS algorithm to design analog beamformers while the digital ones admit closed-form solutions. For the latter, we develop a two-step algorithm based on fractional programming and the PGA-TS method. Simulations show that the proposed SW-HBF schemes are efficient and can outperform PS-based HBF architectures in terms of both SE and energy efficiency in terahertz communication systems.
