適用於二維天線陣列多輸入多輸出毫米波系統混合預編碼追蹤之張量處理器設計及實現

Design and Implementation of Tensor Processor for Hybrid Precoding Tracking in Millimeter Wave 3D-MIMO Systems

吳宗璘(Tsung-Lin Wu)

指導教授 ： 黃元豪

國立清華大學/電機資訊學院/通訊工程研究所/碩士(2021年)

摘要

在第五代行動通訊中，毫米波多輸入多輸出系統被應用來滿足高資料產出量的需求，然而當有大量天線的時候，全數位預編碼的RF鏈在輸入多輸出系統中造成大量的成本，所以混合式預編碼的架構就被用在巨量天線的多輸入多輸出系統來減少RF鏈的數量。傳送在毫米波的訊號有大量的路徑耗損，所以三維多輸入多輸出系統被應用來組成有水平及垂直方向自由度的波束以及中更多能量，張量將可能是一個好的代數工具來表示三維的通道。此篇論文提出一種基於張量的混合式預編碼追蹤演算法來增加頻譜效率，張量分解及正交的特性可以使通道對角化，為了在連續時間的通道中追蹤預編碼，所以將原本的高維度奇異值分解(Higher-order singular value decomposition)由高維正交遞迴(Higher-order orthogonal iteration)取代。此篇論文用QuaDRiGa 通道模型來模擬所提出的演算法，模擬結果顯示所提出的演算法的頻譜效率在SNR低的區域有比較好的表現以及所提出的演算法適合在稀疏性較高的通道被使用。我們也提出了一個硬體架構支援64根傳送天線被實現在FPGA-xcvu19p-fsvb3824-1-e，這個混合式預編碼的處理器的時脈頻率為83.33 MHz，資料產出量可達到每秒 33.280/16.640/11.093 k 個預編碼當演算法遞迴1/2/3次得時候，此資料產出量可以達到通道同調時間的需求。

關鍵字

預編碼 ； 張量 ； 毫米波 ； 多輸入多輸出 ； 追蹤

並列摘要

The millimeter-wave (mmWave) multiple-input multiple-output (MIMO) systems are applied to satisfy the high-throughput requirement in the fifth-generation communication. However, the RF chains of fully digital precoding cost a lot in MIMO systems when the number of antennas becomes massive. The architectures of hybrid precoding are used in massive MIMO systems to reduce the RF chain number. The signals in mmWave have significant path loss, so a three-dimensional (3D) MIMO is applied to form beams in two dimensions to gain more power. Tensor may be a suitable algebraic object to represent a 3D-MIMO channel.
This thesis proposed a tensor-based hybrid precoding tracking algorithm for 3D-MIMO systems to improve spectral efficiency. The tensor decomposition and all-orthogonal property can diagonalize the 3D-MIMO channel. To track the precoder in continuous-time channels, we replace higher-order singular value decomposition (HOSVD) with higher-order orthogonal iteration (HOOI). This thesis simulates the proposed hybrid precoding with the QuaDRiGa channel model in different scenarios. Simulation results show that the spectral efficiency of the tensor-based hybrid precoding tracking is improved in the low SNR regions, and the tensor-based hybrid precoder is suitable for sparse channels.
In addition, we propose the architecture of the proposed hybrid precoding tracking. This architecture supports 64 antennas and is implemented on FPGA-xcvu19p-fsvb3824-1-e. The hybrid precoding processor can operate with 83.33MHz clock speed. The throughput can achieve 33.280/16.640/11.093 k precoders per second for the number of iteration is 1/2/3, respectively, to satisfy the coherence time requirement.

並列關鍵字

precoding ； tensor ； millimeter wave ； multiple-input multiple-output ； tracking

參考文獻

[1] S. K. Yong and C.-C. Chong, “An overview of multigigabit wireless through millimeter wave technology: potentials and technical challenges, ”EURASIP Journalon Wireless Communications and Networking, vol. 2007, no. 1, pp. 1–10, 2006.

[2] S. Sun, T. S. Rappaport, R. W. Heath, A. Nix, and S. Rangan, “Mimo formillimeter-wave wireless communications: beamforming, spatial multiplexing, orboth?” IEEE Communications Magazine, vol. 52, no. 12, pp. 110–121, 2014.

[3] D. Zhang, P. Pan, R. You, and H. Wang, “Svd-based low-complexity hybrid pre-coding for millimeter-wave mimo systems,” IEEE Communications Letters, vol. 22,no. 10, pp. 2176–2179, 2018.

[4] F. Sohrabi and W. Yu, “Hybrid digital and analog beamforming design for large-scale antenna arrays,” IEEE Journal of Selected Topics in Signal Processing, vol. 10,no. 3, pp. 501–513, 2016.

[5] T. G. Kolda and B. W. Bader, “Tensor decompositions and applications,” SIAMReview, vol. 51, no. 3, pp. 455–500, 2009.