IQ失衡補償和VBLAST補償技術應用於 4 × 4多天線輸入多天線輸出60GHz極化多工暨子載波多工暨正交分頻多工光載微波訊號系統

Abstract

由於現今社會已普及性的使用手持式行動裝置，然而在手持式行動裝置中大量使用多媒體影音應用程式。因此對於高畫質、人機互動、雲端儲存技術上的需求大量增加，高容量無線傳輸服務也隨著需求的日與俱增而日新月異，因此無線通訊網絡技術在近年來蓬勃發展且在產業與學術界中備受關注。在無線通訊技術中，其優點包括可移動性及廣泛的涵蓋範圍，因此網路服務不再受限於地區性束縛，無線通訊網路技術快速的成為人們生活中不可或缺的一部分。然而，隨著高畫質時代、人機互動技術與多媒體設備的更新導致無限資料傳輸需求量不斷的增加，無線通訊系統也需隨之發展更新穎的系統技術。而為了追求高資料傳輸效率，頻寬的需求也大幅增加，進而帶動高頻訊號的發展。而在57-64GHz(V-band)間有著7GHz的免認證連續頻帶可供使用，然而在60GHz訊號在傳統電纜與無線空間的傳輸衰減率極高。近年來，結合光纖通訊與60GHz無線通訊系統概念被提出，同時為了增加頻譜使用效率，多天線輸入多天線輸出技術也被應用在此概念中。 在本文提出全新的4 x 4多輸入多輸出系統架構結合光載微波系統以及天線輸入多天線輸出系統，建立在良好的60GHz光載微波訊號系統與2 x 2多天線輸入多天線系統研究上。本文中使用載波錯頻極化多工技術與子載波多工技術結合，不但能成功地避開傳統極化多工導致的能量衰減問題，且不需額外的極化追蹤元件或保護區間，進而再與4 x 4多天線輸入多天線輸出無線通訊系統結合，同時處理多輸入多輸出光訊號與無線訊號。然而在60GHz光載微波訊號系統中有許多需要克服的問題，例如I/Q不平衡效應與60GHz的無線通道響應與元件不平坦響應。所以在本文中將會把通道響應分成許多子矩陣，以理論與模擬的分析來找出決定系統的關鍵因子，然後期許以天線的空間設計與訊號處理技術來克服系統問題。

In Recent years, the populations of using smart device is dramatically increasing. It brings a rapid development of modern network and wireless communication technology. Higher data rate is coupled with large bandwidth in order to support the change of smart device such as 4K-HD TV, Human-Computer Interaction and cloud service. The free-license V-band (57-64 GHz) is able to provide considerably more bandwidth. However, V-band wireless transmission is limited by high propagation loss in air. Radio-over-fiber (RoF) system combines with fiber communication and V-band wireless communication. Moreover, multi-input multi-output (MIMO) technology can also promote spectral efficiency with transmitting multiple signals within the same bandwidth. There is a power decay issue in traditional Polarization multiplexing division (Polmux) system. Several schemes have been proposed to solve this issue by adding polarization tracking or double guard band. This thesis proposed a brand new frequency offset 60-GHz Polmux-SCM-OFDM-RoF system which can solve the decay issue without adding extra component and guard band. Furthermore, proposed system combines 4 x 4 MIMO optical and MIMO wireless system. This thesis separates the channel response into many sub-matrices. Using fundamental principle to analysis the impact factor of the system and simulated method to verify it. In order to solve the impairment from IQ imbalance and uneven frequency response cause by 4 x 4 60-GHz MIMO-wireless channel, this thesis employing digital signal processing technologies include bit-loading algorithm, I/Q imbalance compensation and VBLAST compensation.