本論文旨在提升無線光通訊傳輸之距離與品質以及傳輸通道之干擾測試，且將本論文架構應用在分波多工雙向傳輸之上，每一波道傳輸速度達到10 G bit/s以上。本論文中，利用傳輸距離5公尺為一測量基準，進行許多重要參數之量測，並量測傳輸距離25公尺之誤碼率；傳輸距離5公尺與25公尺之系統損耗為2.5 dB與9.9 dB，作圖觀測後得傳輸距離與系統損耗呈線性關係。在本論文第四章中進行傳輸距離5公尺與25公尺之誤碼率量測，5公尺(單一波長)單向與雙向傳輸之功率償付值分別為0.12 dB與0.25 dB；25公尺(單一波長)單向與雙向傳輸之功率償付值分別為0.49 dB與0.67 dB；25公尺(分波多工)單向與雙向傳輸之功率償付值分別為0.58 dB與0.75 dB，功率償付值皆在1 dB以內。在本論文第五章中進行無線光通訊傳輸通道測試之量測，在系統傳輸時於傳輸通道間加入玻璃、空氣擾動、雨滴干擾等不同的干擾參數，傳輸通道受干擾其接收功率受到衰減；而穿透玻璃後功率衰減之變化從0.63 dB至4.14 dB不等，但經誤碼率量測後得功率償付值皆在0.3 dB以內；空氣擾動則利用蠟燭燃燒之上升熱空氣以製造空氣擾動，接收功率受衰減從0.1 dB至5.8 dB不等；雨滴干擾，利用自行搭建之裝置製造出下雨的情況，接收功率受影響之功率不足0.3 dB。本論文之實驗架構可靈活的安裝於許多位置提供網路的連結，可供架設在大樓之間傳遞訊息，並可減少光纖的鋪設與設置成本。

This work aims at enhance the transmission distance and quality of free-space optical transmission. The adjacent channels interference testing was also evaluated. Then the proposed scheme was applied in wavelength division multiplexing bidirectional point to point system. The data rate per channel is 10 Gbit/s in pseudo-random binary sequence (PRBS) 2-31 format. In this thesis, the transmission distances were 5m for important parameters measurement, and 25 m for bit error rate performance measurement. The system power losses are 2.5 and 9.9 dB, respectively.
We obtained a linear curve for transmission distance versus system power loss. It is because the bean pattern was still smaller than the photo detector area in distance up to 25 m if the beam has been focused by a convex lens. The measured power penalties for 5 m and 25 m unidirectional transmission are 0.12 and 0.49 dB, respectively, as compared to the back-to-back transmission. The bit error rate (BER) performances for unidirectional and bidirectional transmissions have negligible difference. When adjacent channel interference is considered, the measured power penalties for 25 m unidirectional and bidirectional transmission were increased to 0.58 dB and 0.75 dB, respectively. Nevertheless, all the power values are still under system criterion of 1dB.
In Chapter 5, some possible parameters such as window glass, atmospheric turbulence and raindrops were considered, individually, in 5 m free space transmission. The measured power loss for window glass under different align angles ranges from 0.63 to 4.14 dB; corresponding to BER values of less than 0.3 dB. The power loss for atmospheric turbulence ranges from 0.1 to 5.8 dB when candles were used to fit the temperature gradient. And the artificial raindrops induced 0.3 dB power loss during experiment. The measured results are helpful for real case application for building to building, short-haul optical wireless communication.

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