Compressed Training for Dual-Wideband Time-Varying Sub-Terahertz Massive MIMO
Compressed Training for Dual-Wideband Time-Varying Sub-Terahertz Massive MIMO
复制标题
DOI：
10.1109/tcomm.2023.3247789
复制
发表时间：
2022-01
影响因子：
8.3
通讯作者：
Tzu-Hsuan Chou;Nicolò Michelusi;D. Love;J. Krogmeier
中科院分区：
文献类型：
--
作者：
Tzu-Hsuan Chou;Nicolò Michelusi;D. Love;J. Krogmeier
6G运营商可能会使用毫米波（mmWave）和亚太赫兹（sub-THz）频段来满足不断增长的无线接入需求。亚太赫兹通信面临着毫米波通信的许多现有挑战，并增加了与更宽的带宽、更多的天线和更恶劣的传播相关的新挑战。值得注意的是，频率和空间宽带（双宽带）效应在太赫兹以下非常显着。本文提出了一种压缩训练框架来估计时变次太赫兹 MIMO-OFDM 信道。构建了一组频率相关的阵列响应矩阵，从而能够通过多个测量向量 (MMV) 从跨子载波的多个观测值中进行信道恢复。使用时间相关性，设计MMV最小二乘法(LS)来基于先前波束支持来估计信道，并将MMV压缩感知(CS)应用于残余信号。我们将此称为 MMV-LS-CS 框架。针对 MMV-LS-CS 框架提出了两阶段 (TS) 和基于 MMV FISTA (M-FISTA) 的算法。利用扩展损耗结构，提出了一种信道细化算法来估计主要路径的路径系数和时间延迟。为了降低计算复杂度并提高波束分辨率，开发了一种使用分层码本的顺序搜索方法。数值结果表明，与最先进的技术相比，MMV-LS-CS 的信道估计精度有所提高。
6G operators may use millimeter wave (mmWave) and sub-terahertz (sub-THz) bands to meet the ever-increasing demand for wireless access. Sub-THz communication comes with many existing challenges of mmWave communication and adds new challenges associated with the wider bandwidths, more antennas, and harsher propagations. Notably, the frequency- and spatial-wideband (dual-wideband) effects are significant at sub-THz. This paper presents a compressed training framework to estimate the time-varying sub-THz MIMO-OFDM channels. A set of frequency-dependent array response matrices are constructed, enabling channel recovery from multiple observations across subcarriers via multiple measurement vectors (MMV). Using the temporal correlation, MMV least squares (LS) is designed to estimate the channel based on the previous beam support, and MMV compressed sensing (CS) is applied to the residual signal. We refer to this as the MMV-LS-CS framework. Two-stage (TS) and MMV FISTA-based (M-FISTA) algorithms are proposed for the MMV-LS-CS framework. Leveraging the spreading loss structure, a channel refinement algorithm is proposed to estimate the path coefficients and time delays of the dominant paths. To reduce the computational complexity and enhance the beam resolution, a sequential search method using hierarchical codebooks is developed. Numerical results demonstrate the improved channel estimation accuracy of MMV-LS-CS over state-of-the-art techniques.