基於雙邊多頻帶直接偵測光學正交分頻多工系統之高頻譜效益和高分光比被動光學網路研究

High Spectral Efficiency and High Splitting Ratio PON System based on Double-sided Multiband DDO-OFDM System

沈冠恆

指導教授 ： 馮開明

國立清華大學/電機資訊學院/通訊工程研究所/碩士(2013年)

https://doi.org/10.6843/NTHU.2013.00739

摘要

近年來由於寬頻用戶數大幅的成長及網際網路多媒體的服務需求量的增加，以on-off keying (OOK) 所調變的被動光學系統已無法適用於如此高的傳輸量，新一代被動光學網路除了提供了更高的傳輸量之外，在頻譜的分配上更有彈性、效率，相較於傳統G-PON下傳位元傳輸速率2.5Gb/s，NG-PON的傳輸容量將增加至少40Gb/s而傳輸率增加至1Gb/s以上，更適用於現在如此龐大傳輸量的需求。
在本論文中提出了多頻帶直接偵測正交分頻多工的被動光學網路系統，利用光學OFDM的調變方式增加頻譜效益，配合頻譜適當地配置，在直接接收系統裡只需一次濾波即可解調且可避免subcarrier-signal beat interference (SSBI)的干擾，並擷取出其載波當其上傳之載波，大幅地降低接收端系統的複雜度及成本需求，其傳輸速率達120Gb/s、頻譜效益達2.4b/s/Hz、分光率達1:128的6-band系統，接著做更進一步在不同的頻帶分別用不同的QAM數去調變使其傳輸速率達150Gb/s、頻譜效益達3b/s/Hz，分光率比為1:1024的6-band系統。

關鍵字

被動光學網路 ； 正交分頻多工 ； 高頻譜效益

並列摘要

With the progress of nowadays broadband multi-services, such as video-on-demand, video/photo sharing and interacting games etc., the Internet traffic is increasing drastically. Most currently deployed optical passive networks (PON) which employing on-off keying modulation reveal a great insufficiency of data rate. To solve this problem, OFDM, a very popular scheme, has been applied.
In this paper, we demonstrate 120Gbps double-sided multiband OFDMA-PON by using direct detection to demodulate signal. To avoid signal-signal beating interference (SSBI) in inherent square-law photo detection, we use a simple optical band pass filter to sift out the desired OFDM band without SSBI contamination at optical network unit (ONU) receiver. Furthermore, we proposed and successfully demonstrated a water-filling configuration which downstream data rate achieves 150Gbps on single optical carrier. In the transmissions of short-reach pon (SR-PON, 25km) and long-reach pon (LR-PON, 100km), the splitting ratios achieve 1:180 and 1:1024.
At the upstream transmitter in ONU, to decrease the cost we adopt carrier-reused scheme to generate upstream carrier. The modulation scheme is using QPSK format with coherent detection. Finally, we demonstrated a double-sided multiband direct detect optical OFDM (DDO-OFDM) PON system based on a bidirectional configuration.

並列關鍵字

PON ； OFDM ； high spectral efficiency

參考文獻

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