本研究將標準時間訊號藉著SONET/SDH OC-3 155.52 Mbps同步光纖網路的封包，並且在不影響其它ATM資料的使用下傳送。參考NIST MODEM的架構，將系統分成控制與傳送接收標準時間訊號兩大部份，並自行設計製作“標準時間訊號傳送接收電路”及“控制與狀態監控電路”，利用控制電路讓外界（PC端）可以控制及監控光收發模組的狀態；並藉由傳送電路將標準時間1-PPS的訊號傳送到光收發模組中。利用這個光纖傳送標準時間訊號的系統，在無中繼再生的情況下，可以1310 nm單模光纖傳送標準時間訊號至35公里以上，並可達到35公里時一天的頻率穩定度在2.6E-16 ，及進行各種相關的實驗。此系統的性能可達到與現今以GPS全球衛星定位系統來傳送標準時間信號的實驗室系統相當。

We transport the standard time signal by using the single-mode fiber (SMF) media through the synchronous optical network (SONET)/ synchronous digital hierarchy (SDH) data signal, in which the time signal generated from the atomic clock was inserted into the unused bytes in the overhead of the SONET/SDH OC-3 155 Mb/s frame. Based on the NIST MODEM architecture, which was developed by the National Institute of Standard and Technology in the States, the time transfer system is composed of the control unit of the OC-3 transceiver module and the time-signal transmiting/receiving unit. We design and fabricate the required time-signal transmitting/receiving circuits and the control and monitoring circuits. The personal computer (PC) can read/write and monitor the operation status of the optical transceiver module through the control circuit, and the 1-PPS (pulse per second) time signal can therefore be read/written from/into the transceiver module. The frequency stability of about 2.6E-16 within one day can be achieved for this 1310-nm optical-fiber-based time transfer system over a 35-km SMF link without using electronic regererator. Such stability performance is comparable with that of today’s GPS-based time transfer system.

第 1 章 研究基礎 ………………………………………………………………… 1
1-1. 前言 ………………………………………………………………………… 1
1-2. 現有傳時技術介紹 ………………………………………………………… 1
1-3. NIST MODEM簡介 …………………………………………………………… 2
1-3-1. NIST MODEM架構 ……………………………………………………… 2
1-3-2. NIST MODEM的工作方式 ……………………………………………… 3
1-4. 標準時間與頻率訊號及NIST MODEM信號介紹 …………………………… 4
1-4-1. 5 MHz / 10 MHz標準頻率訊號 ……………………………………… 4
1-4-2. 1-PPS標準時間訊號 …………………………………………………… 5
1-4-3. Tx 1-PPS / Rx 1-PPS ………………………………………………… 5
1-5. 光纖雙向傳時系統的架構 ………………………………………………… 6

第 2 章 光電發收模組簡介與工作設定 ………………………………………… 7
2-1. 光電收發模組性能簡介 …………………………………………………… 8
2-2. P1個別針腳的功用 ……………………………………………………… 9
2-2-1.　LIMO提供讀取與寫入SONET Overhead的方式 …………………… 10
2-3. P2個別針腳功能 ………………………………………………………… 11
2-3-1. Dual Port RAM的設定方式 ………………………………………… 13

第 3 章 電路設計與製作 ……………………………………………………… 16
3-1. 控制電路的設計與製作 ………………………………………………… 16
3-1-1. 控制電路內部設計 …………………………………………………… 17
3-1-2. 控制電路與控制電腦命令 …………………………………………… 18
3-2. 利用控制電路讀寫LIMO Dual Port RAM的測試 ……………………… 18
3-3. LIMO傳送與接收Transport Overhead的接腳測試 …………………… 19
3-3.1 Dual Port RAM 0x08c = 0（預設值） ……………………………… 19
3-3.2 Dual Port RAM 0x08c = 2（接受寫入Transport Overhead） …… 21
3-4. 傳送1-PPS的設計 ………………………………………………………… 22
3-5. 設計傳時電路 …………………………………………………………… 23
3-5-1. 計算Transport Overhead位置的計算模組 ………………………… 23
3-5-2. 傳送標準時間訊號至 LIMO 的傳送模組 …………………………… 25
3-5-3. 接收Transport Overhead標準訊號資料的接收模組 ……………… 28
3-5-4. 傳送電路的整體設計 ………………………………………………… 28

第 4 章 標準時間傳送測試與系統性能分析 ………………………………… 31
4-1. 傳送電路傳送測試 ……………………………………………………… 31
4-2. 不同的傳送設定對傳送延遲的影響 …………………………………… 32
4-3. 短距離（5公尺）單模光纖Loop-back傳送1-PPS訊號測試 …………… 33
4-4. 長距離（30公里）單模光纖Loop-back傳送1-PPS訊號測試 ………… 34
4-5. 傳時系統頻率穩定度（Frequency Stability）的分析方法 ………… 35
4-7. 重疊法計算的頻率穩定度（Overlapping Frequency Stability） … 38
4-8. 修飾法計算的頻率穩定度（Modified Frequency Stability） …… 40

第 5 章 光纖傳時系統實驗 …………………………………………………… 42
5-1. 隔離室中光纖傳時實驗 ………………………………………………… 43
5-2. 溫度對光纖傳時的影響 ………………………………………………… 44
5-3. 溫箱之恆溫狀態傳時量測實驗 ………………………………………… 45

第 6 章 結論 …………………………………………………………………… 50

Reference ………………………………………………………………………… 51

附錄 1 LIMO之Dual Port RAM設定值 ………………………………………… 53
附錄2 控制電路電路圖 ………………………………………………………… 63
附錄2-1自製之控制電路設計圖（8051主控制電路） ………………………… 63
附錄2-2 自製之控制電路設計圖（擴充埠電路） …………………………… 64
附錄2-3 自製之控制電路設計圖（LIMO擴充控制介面主電路） …………… 65
附錄2-4 自製之控制電路設計圖（LIMO擴充控制介面雙向讀取電路） …… 66
附錄2-5 控制電路溫測模組設計圖（主要電路） …………………………… 67
附錄2-6 控制電路溫測模組設計圖（類比電路） …………………………… 68
附錄3 控制電路指令表 ………………………………………………………… 69
附錄4 Dual Port RAM 寫入測試資料 ………………………………………… 76
附錄4-1 Dual Port RAM原始設定 ……………………………………………… 76
附錄4-2 寫入所有Dual Port RAM為0xAA ……………………………………… 78
附錄4-2 Reset後Dual Port RAM資料內容 …………………………………… 80
附錄5 1-PPS傳送接收電路設計圖 ……………………………………………… 82

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