Wireless systems operating at mm-wave frequencies require dense antenna arrays to achieve directional gain for overcoming high path loss. Digital mm-wave arrays retain spatial degrees of freedom, but require a dedicated analog to data converter (ADC) per spatial channel, leading to undesirably high receiver complexity, large ADC count, and power consumption. This brief exploits directional sparsity to reduce the number of receivers and ADCs with minimal loss in performance. A multidimensional (MD) linear transformation using transmission lines and a K : 1 combiner is used to reduce the number of ADCs by a factor K. Simulations verify that the proposed method can lead to better than 50% ADC complexity reductions (for K ≥ 2) for linear arrays and more than 75% ADC complexity reduction (for K ≥ 4) for rectangular arrays when sparsity conditions are met. Unlike in analog-digital hybrid beamforming, where a phased-array combines K channels to a single ADC, the proposed method does not lead to loss of spatial degrees of freedom.

中文翻译：

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具有减少 ADC 数量的时空频率复用数字射频阵列接收器


在毫米波频率下运行的无线系统需要密集的天线阵列来实现定向增益，从而克服高路径损耗。数字毫米波阵列保留了空间自由度，但每个空间通道都需要专用的模拟数据转换器 (ADC)，从而导致接收器复杂性过高、ADC 数量较多和功耗较高。本简介利用定向稀疏性来减少接收器和 ADC 的数量，同时将性能损失降至最低。使用传输线和 K : 1 组合器的多维 (MD) 线性变换可将 ADC 数量减少 K 倍。仿真验证所提出的方法可将 ADC 复杂性降低 50% 以上（对于 K ≥ 2 ）对于线性阵列，当满足稀疏条件时，对于矩形阵列，ADC 复杂度降低超过 75%（K ≥ 4）。与模数混合波束形成（相控阵将 K 个通道组合到单个 ADC）不同，所提出的方法不会导致空间自由度的损失。