濾波正交分頻多工(F-OFDM)是基於5G毫米波(mmWave)環境所提出的無線通訊系統，由於它會將整個頻寬分成多個稱為「子頻帶」的頻率區域，因此F-OFDM可應用於物聯網(IoT)以同時執行多個功能。每個子頻帶需要通過濾波來抑制頻帶外泄(out-of-band emission)，並防止鄰近通道干擾(ACI)。然而，通道在現實環境中存在一些非理想效應，如載波頻率偏移(CFO)，它可能破壞相鄰子載波之間的正交性，頻率偏移會降低F-OFDM系統的性能準確性，因此符號時序偏移(STO)的偵測和CFO估計變得十分重要。與傳統OFDM相比，我們提出的架構是可規格化的，簡單來說，它可以支援多種不同的規格，且滿足CFO的補償。在本篇論文中，為了降低硬體成本和功率消耗，我們採用了一種混合形式，同時使用數位和類比架構來實現預編碼。並且，我們將多輸入多輸出(MIMO)的F-OFDM基頻處理器與我們合作團隊所設計的「基於波束搜索(beam search)演算法的射頻組合器(RF combiner)」進行了整合。此外，該硬體架構使用TSMC的40奈米製程，並以200 MHz的運行頻率進行合成與實現，對於整體混合預編碼的MIMO F-OFDM系統，最大吞吐量可達到1.13 Gbps。

Filtered Orthogonal Frequency Division Multiplexing (F-OFDM) was proposed for 5G wireless communication systems. Meanwhile, it can be applied to several works since the whole bandwidth is split into small frequency regions, which is called “sub-band”. Each sub-band needs to suppress out-of-emission by filtering and prevent adjacent-channel interference (ACI). However, the channel has some non-ideal effects in the real environment such as carrier frequency offset (CFO). It can destroy the orthogonality between adjacent subcarriers. Frequency offset reduces the accuracy of performance in the FOFDM systems, so it is important to carry out symbol timing offset (STO) detection and CFO estimation. In contrast to traditional OFDM, the architecture which we proposed is reconfigurable. To put it simply, it can support over ten different specifications and also satisfy the recovery of CFO. In this work, to decrease the hardware cost and consumption by power, we adopted a hybrid form to implement precoder and combiner with digital and analog. Then, we integrated the multiple-input multiple-output (MIMO) F-OFDM baseband processor with a baseband combiner and beam search RF combiner designed by our cooperation team. Furthermore, the entire hardware is also synthesized and implemented by TSMC 40nm process with 200 MHz operating frequency. The maximum throughput can reach 1.13 Gbps for overall hybrid-precoding MIMO filtered-OFDM.

摘要
1 Introduction 1
1.1 Modulations of 5G MIMO Systems . . . . . . . . . . . . . . . . . . . . . 1
1.2 Effects of Frequency Offset . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.3 Hybrid Precoding Architecture . . . . . . . . . . . . . . . . . . . . . . . . 4
1.4 Research Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.5 Organization of This Thesis . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.6 Notations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2 Hybrid-Precoding Filtered-OFDM System 7
2.1 MIMO Channel Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.2 Hybrid-Precoding and Combining for mmWave MIMO Systems . . . . . 10
2.2.1 Modified Block SVD Power Method Baseband Precoding [1] . . . 11
2.2.2 Square Root Baseband Combining [2] . . . . . . . . . . . . . . . . 12
2.2.3 RF Precoding and Combining with Beam Search [3] . . . . . . . . 15
2.3 Filtered Orthogonal Frequency Division Multiplexing [4] . . . . . . . . . 18
2.3.1 Transmitter Architecture . . . . . . . . . . . . . . . . . . . . . . . 18
2.3.1.1 Cyclic Prefix (CP) Insertion . . . . . . . . . . . . . . . . 20
2.3.1.2 Up-sampling and Filtering . . . . . . . . . . . . . . . . . 21
2.3.1.3 Up-conversion . . . . . . . . . . . . . . . . . . . . . . . . 25
2.3.2 Receiver Architecture . . . . . . . . . . . . . . . . . . . . . . . . . 27
2.3.2.1 Down-conversion and Filtering . . . . . . . . . . . . . . 27
2.3.2.2 Time Synchronization . . . . . . . . . . . . . . . . . . . 28
2.3.2.3 Channel Estimation . . . . . . . . . . . . . . . . . . . . 31
3 Integrated Architecture of Hybrid-Precoding MIMO F-OFDM with
Synchronization and Simulation Results 33
3.1 Systems of Synchronization . . . . . . . . . . . . . . . . . . . . . . . . . 36
3.2 Synchronization of Fractional Carrier Frequency Offset (FCFO) . . . . . 38
3.3 Synchronization of Integer Carrier Frequency Offset (ICFO) . . . . . . . 40
3.4 Recovery of Carrier Frequency Offset . . . . . . . . . . . . . . . . . . . . 41
3.5 Specifications of Different Numerologies and Parameters . . . . . . . . . 43
3.6 Simulation Results and Analysis . . . . . . . . . . . . . . . . . . . . . . . 46
4 Hardware Architecture 57
4.1 VLSI of Filtered-OFDM . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
4.1.1 Filter Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
4.1.2 STO Detection and CFO Estimation . . . . . . . . . . . . . . . . 61
4.1.3 Numerical Control Oscillator (NCO) . . . . . . . . . . . . . . . . 64
4.1.4 Channel Estimation . . . . . . . . . . . . . . . . . . . . . . . . . . 65
4.2 VLSI of Baseband Combiner . . . . . . . . . . . . . . . . . . . . . . . . . 66
4.3 Timing Schedule . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
4.4 Synthesis Results of Integrated Hardware . . . . . . . . . . . . . . . . . . 68
5 Conclusion 71
References 73

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