下一代系统中的单用户交互式波束对准：深度学习观点
On Single-User Interactive Beam Alignment in Next Generation Systems: A Deep Learning Viewpoint
摘要：
毫米波和太赫兹等高频通信存在高路径损耗和强阴影效应，需要波束形成来实现可靠的数据传输。另一方面，在高频率下，信道是稀疏的，并且由很少的空间簇组成。因此，波束对准（BA）策略被用来找到这些信道簇的方向，并调整用于数据传输的波束的宽度。在这项工作中，被认为是一个单用户上行链路的情况下，信道有一个占主导地位的集群。假设用户在固定的持续时间内发送一组BA分组。同时，基站（BS）使用不同的探测波束扫描不同的角度区域。由于BS测量是有噪声的，因此不可能以概率1找到包括用户的到达角（AoA）的窄波束。因此，BS向用户分配窄波束，该窄波束包括具有预定错误概率的用户的AoA，同时最小化所分配波束的预期波束宽度。由于这个有噪声的BA问题的棘手性，这里这个问题被提出作为深度神经网络（DNN）的端到端优化，并且讨论和研究了不同损失函数的影响。据观察，所提出的基于DNN的BA在高SNR下实现了接近于无噪声时的最佳BA的性能，并且对于所有SNR，优于现有技术。
英文摘要：
Communication in high frequencies such as millimeter wave and terahertz suffer from high path-loss and intense shadowing which necessitates beamforming for reliable data transmission. On the other hand, at high frequencies the channels are sparse and consist of few spatial clusters. Therefore, beam alignment (BA) strategies are used to find the direction of these channel clusters and adjust the width of the beam used for data transmission. In this work, a single-user uplink scenario where the channel has one dominant cluster is considered. It is assumed that the user transmits a set of BA packets over a fixed duration. Meanwhile, the base-station (BS) uses different probing beams to scan different angular regions. Since the BS measurements are noisy, it is not possible to find a narrow beam that includes the angle of arrival (AoA) of the user with probability one. Therefore, the BS allocates a narrow beam to the user which includes the AoA of the user with a predetermined error probability while minimizing the expected beamwidth of the allocated beam. Due to intractability of this noisy BA problem, here this problem is posed as an end-to-end optimization of a deep neural network (DNN) and effects of different loss functions are discussed and investigated. It is observed that the proposed DNN based BA, at high SNRs, achieves a performance close to that of the optimal BA when there is no-noise and for all SNRs, outperforms state-of-the-art.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
