隨著科技日新月異的快速發展，人們追求更高速且穩定的網路連線品質，也因此第五代行動通訊(5th generation mobile networks)成為了當今的熱門研究項目，也因此發展出了眾多通訊調變方式，其中，為了更有效的利用頻譜效益(Spectral efficiency)以及達成物聯網(Internet of Things, IoT)裝置低功耗(Low Power Consumption)且低成本(Low Cost)的願景，能夠在相同頻譜資源上疊加更多使用者的非正交多重存取(Non-orthogonal multiple access, NOMA)的其中一種技術：稀疏碼多工存取(Sparse Code Multiple Access, SCMA)被視為是極有潛力發展於物聯網系統的通訊技術之一。
雖然SCMA技術被視為是物聯網的潛力技術之一，但是由於解調時需要的高複雜度會增加在下傳時IOT的終端裝置的能源消耗，也為此與IOT的需求相互違背，由於IOT的裝置終端多設置於電源不易供給的位置，多半依靠電池使裝置能正常使，由此可知降低複雜度及電源消耗就成為了重要的課題。本論文引用了低複雜度的稀疏碼多工存取(Low Complexity Sparse Code Multiple Access, LC-SCMA)技術來降低IOT的終端元件對於能量的消耗，同時藉由每個使用者將EVM(Error Vector Magnitude)的資料回傳給基地台，讓基地台有足夠的資訊分配給每個使用者最適合它們的碼本(Codebook)，藉此來提升LC-SCMA傳輸在較符合現今城市當中的瑞利衰落環境通道(Rayleigh fading channel)下的性能表現。

With the rapid development of technology, there is a growing demand for higher-speed and more stable network connectivity. As a result, the fifth generation of mobile networks (5G) has become a hot research topic. Various communication modulation techniques have been developed to improve spectral efficiency and achieve the vision of low power consumption and low cost for Internet of Things (IoT) devices. Non-orthogonal multiple access (NOMA) is one such technique, and Sparse Code Multiple Access (SCMA) is considered a promising communication technology for IoT systems.
While SCMA is regarded as a potential technology for IoT, its high complexity during demodulation increases the energy consumption of IoT devices in downlink transmissions. This contradicts the low power requirements of IoT devices, as many of them are deployed in locations with limited power supply and rely on batteries. Thus, reducing complexity and power consumption have become important considerations. This study utilizes the Low Complexity Sparse Code Multiple Access (LC-SCMA) technique to minimize energy consumption in IoT devices. Additionally, by providing Error Vector Magnitude (EVM) feedback from each user to the base station, the base station can allocate the most suitable codebook to each user, thereby enhancing the performance of LC-SCMA transmission in urban environments characterized by Rayleigh fading channels.

目錄
中文摘要 I
ABSTRACT II
致謝 III
目錄 IV
圖目錄 VI
表目錄 VIII
第 1 章 緒論 1
1.1 前言 1
1.2 研究動機與目的 3
1.3 論文架構 4
第2章 原理介紹 5
2.1正交分頻多工 5
2.2光電調變器：MACH-ZEHNDER MODULATOR(MZM) 8
2.3光學OFDM系統的直接檢測機制 10
2.4 可程式化光學濾波器 13
第3章 非正交多重存取技術 15
3.1非正交多重存取技術 15
3.2功率域非正交多重存取技術 16
3.3稀疏碼多工存取 18
3.3.1 訊息交換演算法 21
3.4低複雜度稀疏碼多工存取 25
3.4.1低複雜度稀疏碼多工存取碼本安排 25
3.4.2低複雜度稀疏碼多工存取星座圖設計 28
3.4.3平行最大事後機率演算法 32
3.4.4 SCMA被動式多重碼本設計 33
3.5利用適應性碼本分配改善表現 36
3.5.1適應性多重碼本分配 37
第4章 實驗設置及結果 42
4.1光纖整合無線網路 42
4.2 實驗架構與參數 43
4.3 實驗結果 46
4.3.1 1.5-m 毫米波無線傳輸 47
4.3.2 1.5-m 毫米波與光纖 B2B 傳輸 51
4.3.3 1.5-m 毫米波與光纖 25km 傳輸 55
第5章 結論 59
參考文獻 60

參考文獻
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