請用此 Handle URI 來引用此文件:
http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/77692
標題: | 雙模雷射二極體第五代移動毫米波無線光纖接取網路 Dual-Mode Laser Diode Based 5th Generation Mobile Millimeter-Wave Over Fiber Access Network |
作者: | Cheng-Ting Tsai 蔡政庭 |
指導教授: | 林恭如(Gong-Ru Lin) |
關鍵字: | 第五代行動通訊網路,毫米波光纖整合系統,注入鎖定,無色雷射二極體,垂直共振腔面射型雷射,平方功率波包檢測,毫米波中心載波抑制, 5G mobile network,Millimeter-wave over fiber,Injection-locking,Colorless laser diode,VCSEL,Square-law power envelope detection,Central carrier suppression, |
出版年 : | 2017 |
學位: | 博士 |
摘要: | 目前,以毫米波載波為傳輸媒介之毫米波光纖整合系統可建構與發展高適應性與高傳輸速率之行動接取網路給予未來第五代行動通訊系統使用,其使用了雙模光載波搭訊號,並於光接收端利用外差式偵測技術全光升頻所搭載基頻訊號至毫米波頻段以供無線傳輸使用。此論文中,我們將以單模與雙模注入鎖定式無色雷射二極體與垂直共振腔面射型雷射產生雙模光源以建構頻段為38與60 GHz之毫米波光纖整合系統。
第一部分,我們將探討正交分頻多工訊號直調於注入鎖定式無色雷射二極體之傳輸性能。我們發現若要優化預放大正交分頻多工訊號的傳輸性能,無色雷射二極體之偏壓電流與注入鎖定功率必須同時提升以達到截波的避免、相對強度雜訊的抑制與調變頻寬的拓展。我們亦從正交分頻多工訊號經光纖傳輸後之接收功率模型發現,光纖色散所引起的能量衰減效應與無色雷射二極體的偏壓電流呈現正相關。因此我們在研究中使用了子載波預補償技術來抵抗因偏壓電流提升而增強的能量衰減效應,進而使256進制正交分頻多工訊號可以40 Gbit/s之傳輸速率傳輸於25公里單模光纖,且功率代償僅為4.2 dB。 其次,我們發現當無色雷射二極體被雙模注入鎖定時,其產生之三階非線性互調失真可被大幅度的抑制,並輸出高品質的雙模光源以建構頻段為60 GHz之毫米波光纖整合系統,成功攜帶傳輸速率為6 Gbit/s之16進制正交分頻多工訊號於4公里單模光纖與3公尺自由空間傳輸。另一方面,我們引用單模注入鎖定式的無色雷射二極體作為下行光源,並於遠端節點與可調式雷射進行耦合產生非同調雙模光源,並在產生過程中達成單載波調變,以能免除能量衰減效應對全光升頻後的訊號造成影響。於無線接收端我們使用平方功率波包檢測技術使毫米波頻段訊號能以自我降頻方式穩定降至基頻。最後在Volterra與功率預補償技術的幫助下,非同調雙模光源可成功攜帶傳輸速率為16.5 Gbit/s之32進制正交分頻多工訊號於11個高密度分波多工通道中進行50公里單模光纖與3公尺自由空間傳輸。 最後,我們利用破壞性干涉拍頻的方式偵測雙模垂直共振腔面射型雷射所建構之正交極化雙模光載波,使拍頻產生之38 GHz毫米波中心載波可被抑制達33.3 dB,使攜帶之正交分頻多工訊號於電放大過程中獲得更多增益,最後載單載波調變的幫助下成功攜帶位元率為12 Gbit/s之16進制正交分頻多工訊號進行50公里單模光纖與4公尺自由空間傳輸。為使毫米波中心載波抑制效果提升,我們進一步利用破壞性干涉拍頻的方式偵測以單模注入鎖定垂直共振腔面射型為基礎建構之四模光載波,其可抑制拍頻產生之毫米波中心載波達>38 dB,並且使其攜帶速率為12 Gbit/s之16進制正交分頻多工訊號可成功傳輸於50公里單模光纖與4公尺自由空間。 Fusion of 5th generation (5G) mobile network with millimeter-wave over fiber (MMWoF) systems for increasing available bands and promoting transmission capacity has become one of the adaptive emerging communication networks, which delivers the MMW carrier over optical fiber by using a dual-mode light source for optoelectrically converting the carried data to MMW band with heterodyne detection. In this thesis, the directly modulated colorless laser diode (CLD) and vertical-cavity surface-emitting laser (VCSEL) are employed under single-mode and dual-mode injection-locking to generate the dual-mode optical carrier for the MMWoF system at 38 and 60 GHz. First of all, the direct modulation of the injection-locked CLD with the pre-amplified quadrature amplitude modulation orthogonal frequency division multiplexing (QAM-OFDM) data is demonstrated. Optimizing the pre-amplified QAM-OFDM data must be concurrently raised the bias current and injection power of the CLD to avoid the waveform clipping, suppress the relative intensity noise, and enlarge the modulation bandwidth. The simulation of the receiving power for the fiber transmitted QAM-OFDM data indicates that the chromatic dispersion induced RF power fading is enhanced with increasing the bias current, which can be pre-compensated by using the OFDM subcarrier pre-leveling. At an optimized bias current, injection-power, and pre-leveling slope, the injection-locked CLD can successfully transmit the pre-amplified 256-QAM OFDM data at 40 Gbit/s over 25-km single-mode fiber (SMF) with a receiving power penalty of 4.2 dB. Under dual-mode injection-locking, the CLD can output the dual-mode carrier with the suppressed third-order intermodulation distortion for the 60-GHz MMWoF system, which can deliver the 6-Gbit/s 16-QAM OFDM data over 4-km SMF and 3-m free-space. The mutually incoherent dual-mode optical carrier is employed to implement the local-oscillator-free long-reach MMWoF system, which is remotely generated by coupling the down-stream transmitted CLD under single-mode injection-locking with the localized tunable laser. This operation also achieves the optical single-carrier modulation to release the RF power fading effect after heterodyne detection. The square-law power envelope detection is used at the wireless receiving end to avoid the MMW carrier frequency fluctuation induced down-conversion instability. Introducing the Volterra compensation and pre-emphasis techniques to compensate the 2nd-order noises and SNR response allows the 16.5-Gbit/s 32-QAM OFDM data that can be delivered over 50-km SMF and 3-m free-space in 11 DWDM channels. The MMW central carrier suppression is achieved by destructively interfered beating the dual-mode VCSEL, which suppresses the generated MMW central carrier at 38 GHz by 33.3 dB, improving the gain competition of the carried QAM-OFDM data. With the help of optical single-carrier modulation, the carried 16-QAM OFDM data at 12 Gbit/s can be transmitted over 50-km SMF and 4-m free-space. By destructively interfered beating the even and the odd modes of the quad-mode optical carriers that is encoded by single-mode injection-locking the VCSEL, the MMW central carrier at 40 GHz can be suppressed by >38 dB, which can deliver the 16-QAM OFDM data at 12 Gbit/s over 50 km in SMF and 10 m in free-space. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/77692 |
DOI: | 10.6342/NTU201703388 |
全文授權: | 未授權 |
顯示於系所單位: | 光電工程學研究所 |
文件中的檔案:
檔案 | 大小 | 格式 | |
---|---|---|---|
ntu-106-D01941024-1.pdf 目前未授權公開取用 | 7.54 MB | Adobe PDF |
系統中的文件,除了特別指名其著作權條款之外,均受到著作權保護,並且保留所有的權利。