Frequency-Selective Analog Beam Probing for Millimeter Wave Communication Systems
Frequency-Selective Analog Beam Probing for Millimeter Wave Communication Systems
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DOI：
10.1109/wcnc45663.2020.9120815
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发表时间：
2020-05
期刊：
影响因子：
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通讯作者：
C. Jans;Xiaohang Song;W. Rave;G. Fettweis
中科院分区：
文献类型：
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作者：
C. Jans;Xiaohang Song;W. Rave;G. Fettweis
本文主要研究毫米波通信系统的初始波束捕获/对准技术。为了检测到达角(AOA)和/或离开角(AOD)，我们提出了一种训练协议，该协议利用毫米波信道的稀疏性同时检测给定码本中的所有波束形成器。通过应用频率选择性波束探测网络，我们可以将码本中的每个波束形成器映射到不同的频率，并且接收器处的频谱分析允许我们推断出有利的波束形成器或AOD。出于实际原因，我们详细阐述了将方向映射到频率映射的思想，即将每个波束形成器映射到特定的导频子载波。在两种不同的硬件设计下，我们研究了为现有的ofdm通信系统旁边的一个额外的射频(RF)链构建这种波束形成器到频率映射的可行性。结果表明，在快时变环境中，由于时间效率高，并行波束训练能够获得比穷举搜索更好的有效传输速率。这对于毫米波通信系统至关重要，这些系统可以访问大型波束形成码本，但由于移动性和高空间分辨率而存在相干时间较短的问题。
This work focuses on the initial beam acquisition/alignment of millimeter wave (mmWave) communication systems. To detect the angle of arrival (AoA) and/or angle of departure (AoD), we propose a training protocol which probes all beamformers from a given codebook simultaneously by exploiting the sparse nature of mmWave channels. By applying a frequency-selective beam probing network, we can map each beamformer from the codebook to different frequencies and a spectral analysis at the receiver allows us to deduce favorable beamformers or AoDs. For practical reasons, we elaborate this idea of steering direction to frequency mapping for an orthogonal frequency division multiplexing (OFDM) communication system, i.e., we map each beamformer to specific pilot subcarriers. Under two different hardware designs, we investigate the feasibility of building such beamformer to frequency mappings for one additional radio frequency (RF) chain next to an existing OFDM communication system. We show that parallel beam training is able to achieve better effective transmission rates than exhaustive search in fast-time varying environments due to high temporal efficiency. This is crucial for mmWave communication systems which have access to large beamforming codebooks but suffer from short coherence times due to mobility and high spatial resolution.