Two-Dimensional Spreading Codes for Multimedia Services in Optical CDMA Systems

近年來隨著光纖分碼多工技術的日益成熟，以及二維波長跳躍-時間展頻(或稱為波長-時間)編碼技術的蓬勃發展，帶動整個光纖通訊領域的研究風潮。相較於傳統僅使用一個維度的編碼技術，二維波長-時間編碼技術除了可以有效增加系統中可提供之同時使用者數目外，更具有改善系統效能與提供較彈性的設計等優點。因此，本論文將針對使用這種二維編碼技術的設計概念，提出數個應用於光纖分碼多工系統的二維波長-時間碼，並且提供其系統效能的理論分析與推導。 首先，在論文的第一部份提出一個具有較多碼數目與最大相關性函數值為2的新式二維波長-時間碼，稱之為二次同餘載波跳頻質數碼。並將其應用於多碼鍵移光纖分碼多工系統，藉由指定每個用戶多個碼字來進行資料傳輸，以取代傳統光纖分碼多工系統中僅分配每個用戶一個碼字來進行資料傳輸的開關鍵移系統。由於所傳送的每個碼字用來表示帶有數個位元資料的符元，因此不僅可以提高系統的資料傳輸速率，在碼字的保密方面也獲得改善。同時透過理論分析的結果可以發現，多碼鍵移光纖分碼多工系統在系統效能、資料傳輸速率、碼字的保密性與硬體複雜度上提供較佳的折衷解決辦法。 由於人們對於資料、語音及影像等多媒體通訊服務的高度需求，未來的通訊系統能夠同時支援不同的傳輸速度與服務品質的多媒體服務是必然的發展趨勢。因此將針對論文第一部份所提出的二次同餘載波跳頻質數碼，提出”多碼長”的編碼架構，利用指定每個用戶不同碼長的展頻碼來達到提供不同傳輸速率的通訊服務之目的。透過理論分析結果可知使用多碼長展頻碼之光纖分碼多工系統的效能表現，會隨著碼長的減少而獲得改善，相較於傳統使用單一碼長之展頻碼進行資料傳輸的光纖分碼多工系統，對於高傳輸品質需求的服務(如語音、影像等多媒體傳輸服務)具有較高優先權的傳輸特性，因此更適合應用於多媒體光纖分碼多工系統。此外，針對所提出多碼長二次同餘載波跳頻質數碼，探討正規化頻譜效益與碼長之間的關係。分析結果顯示正規化頻譜效益隨著使用短展頻碼的用戶數目的增加而獲得改善，但也同時減少系統中可支援之同時使用者數目。因此必須根據系統效益與可支援之同時使用者數目的重要性，有效率地分配系統中所採用展頻碼的碼長分佈。 除了傳輸速率外，在多媒體通訊服務中另一個必須考量的重要議題為系統的服務品質。在本論文提出數個多碼重多碼長展頻碼的編碼架構，透過使用不同碼重與碼長之展頻碼達到支援系統不同服務品質與多速率傳輸的多媒體應用服務之目的。同時由理論分析的結果可知，多速率傳輸的提供僅能利用調整展頻碼的碼長來達成，然而展頻碼的碼重相較於碼長為決定系統效能的主要因素。此外所設計的展頻碼由於具有多碼長編碼的特性，能夠優先提供高速率與高品質的多媒體傳輸，因此將更適合應用於多媒體光纖分碼多工系統。 最後，本論文提出一個新設計的二維波長-時間碼，稱之為雙極-雙極碼，主要是用來改善傳統使用一維展頻碼的光纖分碼多工系統中之可同時使用者數目與系統效能受限於展頻碼碼長的缺點。同時透過理論分析的結果可知，所提出的二維展頻碼在波長跳躍與時間展頻上均使用雙極碼，相較於僅在波長跳躍使用雙極碼，而在時間展頻上採用單極碼之雙極-單極碼而言，所提出的雙極-雙極碼在和雙極-單極碼有相同碼個數的條件下，具有較佳的系統效能表現。Two-dimensional (2-D) wavelength-hopping time-spreading (or so-called wavelength-time) coding schemes have been studied recently for supporting greater numbers of subscribers and simultaneous users than conventional one-dimensional approaches in optical code-division multiple-access (O-CDMA) systems. In this dissertation, several new families of wavelength-time codes are constructed and analyzed. First, a new family of 2-D wavelength-time codes, so-called quadratic-congruence carrier-hopping prime codes (QC-CHPC) with expanded code cardinality and the maximum cross-correlation function of two (i.e., λc=2) is constructed and analyzed. One application of the large code cardinality of our λc=2 codes is multicode-keying wavelength-time O-CDMA, in which each user is allocated with multiple code matrices, instead of just one code matrix in the conventional on-off keying (OOK) O-CDMA. System throughput is increased because a lower baud rate O-CDMA system can be used to support higher bit-rate transmission since each code matrix is used to represent a "symbol" of several data bits. User code confidentiality is improved because of symbol transmission. The theoretical results show that there is a trade-off between the performance and the number of code matrices per user. It is expected that future communication systems support a variety of services (e.g., data, voice, and video). Users with different bit-rate and quality-of service (QoS) requirements will be accommodated simultaneously. To support multimedia services with different discrete bit-rate requirements, "multiple-length" QC-CHPCs are constructed algebraically in the dissertation. In contrary to conventional single-length codes, our analysis shows that the performance of these multiple-length codes improves as the code length decreases, thus supporting services prioritization in O-CDMA. Moreover, the relationship of the normalized spectral efficiency (NSE) and code lengths of the multiple-length QC-CHPCs is studied. Our results show that the NSE improves as the number of simultaneous users with short code matrices increases, which, however, decreases the total number of simultaneous users in the systems. Thus, the choice of which code-length distribution to use depends on whether system efficiency or total number of the simultaneous users is important. Furthermore, QoS is another important issue to be considered in multimedia applications. One way to adjust QoS in O-CDMA is through weight variations in code matrices, besides changing length. In the dissertation, the constructions of the variable-weight, multiple-length CHPC, Extended CHPC (ECHPC), and mutli-wavelength optical orthogonal code (MWOOC) are proposed and analyzed. Our results show that the performance of these variable- weight, multilength codes could be controlled by matrix length, weight, but bit rate is only controlled by matrix length. Our study also shows that short-length codes generate stronger interference than long-length codes. This supports services prioritization in O-CDMA. Moreover, we also show that code weight is the dominating factor in controlling code performance and, thus, is important in guaranteeing the QoS of those media (e.g., video) that require high bit-rate and real support. Finally, a new family of 2-D wavelength-time codes, so-called bipolar-bipolar codes, is proposed for supporting substantially more subscribers and simultaneous users than conventional 1-D O-CDMA codes in the dissertation. The new codes use bipolar codes for both wavelength hopping and time spreading. As a result, the performance of the bipolar-bipolar coding scheme is better than the bipolar-unipolar coding scheme which uses bipolar codes for wavelength hopping, but unipolar codes for time spreading, while the code cardinality is as good as the latter.1 Introduction 1 2 Wavelength-Time Codes with Maximum Cross-Correlation Function of Two for Multicode-Keying Optical CDMA 4 2.1 Introduction ........................................4 2.2 Quadratic-Congruence Carrier-Hopping Prime Codes ....6 2.3 Analysis of OOK O-CDMA with QC-CHPCs ...............10 2.4 Analysis of Multicode-Keying O-CDMA with QC-CHPCs ..11 2.5 Analysis of Multicode-Keying O-CDMA with Time-Shifted QC-CHPCs ..............................17 2.6 Summary ............................................20 3 Spectral Efficiency Study of QC-CHPCs in Multirate Optical CDMA System 21 3.1 Introduction .......................................21 3.2 Multiple-Length QC-CHPCs ...........................22 3.2.1 Construction Algorithm .......................23 3.2.2 Correlation Properties .......................25 3.3 Performance Analyses ...............................27 3.3.1 Multiple-Length QC-CHPCs in OOK O-CDMA .......28 3.3.2 Multiple-Length QC-CHPCs in Multicode-Keying O-CDMA .......................................31 3.4 Normalized Spectral Efficiency .....................35 3.4.1 Single-Length CHPCs and QC-CHPCs .............37 3.4.2 Multiple-Length QC-CHPCs .....................38 3.5 Summary ............................................41 4 Variable-Weight, Multiplength Optical Codes for Wavelength-Time O-CDMA Multimedia Systems 43 4.1 Introduction .......................................43 4.2 Variable-Weight, Multilength Wavelength-Time Codes..44 4.3 Performance Analysis ...............................47 4.4 Numerical Examples .................................53 4.5 Summary ..............................................55 5 Wavelength-Hopping Time-Spreading O-CDMA with Bipolar Codes 60 5.1 Introduction .......................................60 5.2 Construction of Bipolar-Bipolar Codes ..............61 5.2.1 Cardinality ..................................65 5.3 Performance Analysis ...............................65 5.3.1 Spectral Efficiency ..........................69 5.4 Hardware Implementation ............................71 5.5 Summary ............................................75 6 Conclusions 77 A Proof of Theorem 2.1 79 B Proof of Lemma 3.1 80 C Derivation of Fj'' of the MWOOC 81 D Analysis of Double-Weight, Triple-Length ECHPC 84 E Analysis of Triple-Weight, Triple-Length CHPC 86 F Proof of Lemma 5.1 89 Bibliography 9

Architecture and Performance Analysis on Wireless Local Area Networks with CCK Modulation

在本論文中，首先對所提出的無線區域網路之基頻處理器的基本架構，分為傳送端與接收端兩大部分作完整詳細的介紹與說明。並且針對接收端的互補碼解調變器，提出了一個採用兩階段相關性運算的新解調變架構，以達到降低硬體複雜度與節省功率消耗的目的。 同時，藉由互補碼的正交特性，利用MFSK正交信號檢測的觀念配合應用於同調檢測系統中信號間距離、信號能量與錯誤率的關係，對互補碼解調變系統在AWGN環境下的效益進行理論值的分析。最後，在欲達到降低雜訊放大效應與硬體複雜度的雙重考量下，採用了使用最小均方根（Least Mean Square；LMS）演算法的決策回授等化器（Decision Feedback Equalizer；DFE）以補償在高傳輸速率下由通道所造成的符號間干擾（Intersymbol Interference；ISI）的現象。 本論文所提出的兩階段相關性運算的新解調變架構，在性能的表現上逼近於傳統的解調變架構，同時在硬體上約可降低50%複雜度與平均節省約25%的功率消耗。至於，在硬體複雜度的考量下所採用的LMS演算法的DFE，經模擬證明在室內無線網路的環境下仍有不錯的表現。In this thesis, the architecture of wireless LAN on transmitter and receiver are introduced respectively. A new bi-stage correlation calculation demodulation structure which can achieve the purposes of decreasing the complexity of hardware and reducing the power consumption is proposed. In addition, we utilize the notion of noncoherent detection of MFSK orthogonal system and relation among the symbol energy and distance between the signal points to analyze the performance of CCK modulation in AWGN environment. Finally, in order to reduce the noise enhancement and complexity of hardware, a decision feedback equalizer (DFE) used the least-mean-square (LMS) algorithm is adopted in receiver to compensate the effect of interference (ISI) caused by channel. The proposed new bi-stage correlation calculation demodulation structure in this thesis yields the performance to approach the traditional demodulation structure, and the hardware complexity and power consumption of demodulation structure are reduced. The DFE based on LMS algorithm is performed better under the wireless network environment.1Introduction……………………………………………………1 1.1Background……………………………………………………1 1.2The Standard of the Technique of WLAN………………4 1.3Organization…………………………………………………9 2System Architecture of WLAN………………………………10 2.1Overview……………………………………………………10 2.2Transmitter………………………………………………11 2.2.1The Format of the Transmitter Packet……………11 2.2.2Function Descriptions of Transmitter……………13 2.3Receiver……………………………………………………22 2.3.1Acquisition Stage……………………………………24 2.3.2Data Stage………………………………………………25 2.3.3Function Descriptions of Receiver…………………26 3Bi-Stage Correlation Calculation CCK Demodulation Structure.…36 3.1Complementary Code Keying Modulation………………36 3.1.1The Structure of 11 Mbps CCK Modulation…………38 3.1.2The Structure of 5.5 Mbps CCK Modulation………39 3.2Complementary Code Keying Demodulation……………40 3.2.1The Structure of 11 Mbps CCK Demodulation………40 3.2.2The Structure of 5.5 Mbps CCK Demodulation……42 3.2.3Function Description of Fast Walsh Transform Block…42 3.3New CCK Demodulation Structure — Bi-Stage Correlation Calculation Demodulation Structure………………………45 3.3.1Assigning Numbers to CCK Codewords………………45 3.3.2Orthogonality of the CCK Codewords………………46 3.3.3New Proposed Bi-Stage Correlation Calculation Structure- Modified FWT Structure………………………………………47 3.4Simulation and Summary…………………………………52 4The Performance Analysis of CCK Modulation on WLAN……55 4.1Noncoherent Detection of Orthogonal MFSK……………56 4.2Two Essential Notions of Theoretical Derivation of CCK Performance…62 4.2.1The Relation among the Symbol Energy and Distance between the Symbols…………………………………………………62 4.2.2Modify the Formula of Error Probability of Orthogonal FSK…………66 4.3The Theoretical Derivation of CCK Performance in AWGN Environment…70 5The Techniques of Channel Equalization…………………83 5.1Introduction…………………………………………………83 5.2Channel Model…………………………………………………84 5.3Equalization Techniques……………………………………86 5.3.1Raised Cosine Spectrum Technique………………………86 5.3.2Correlative-Level Coding Technique……………………88 5.3.3Equalizer Technique………………………………………90 5.4Adaptive Equalizer……………………………………………90 5.4.1Types of the Equalizer……………………………………91 5.4.2Criterion……………………………………………………94 5.4.3Algorithm……………………………………………………96 5.5Simulation and Summary……………………………………100 6Conclusion………………………………………………………105 Bibliography……………………………………………………10

手機藍牙機械手臂

[[abstract]]本研究主要在探討如何將手機、藍牙模組、arduino及機械手臂等硬體與app inventor 2程式及arduino的C程式等軟體整合在一起，使機械手臂能以自動與人工兼具的方式完成物件抓取的功能。系統整合是一件困難的事，透過本研究可以初步了解其中的奧秘，並熟悉各領域的基本知識。在研究的過程中，除了致力於分析設計外，也進行了很多零件及組合測試，了解其性能與誤差，然後在最後的階段據此進行補償校正，使系統成功的完成了抓物的功能。本研究所採用之機械手臂，雖然表面上只有四個自由度，但事實上，它仍應屬於五個自由度的範疇。因為其中一個自由度，即爪子俯仰方向的控制，係巧妙的以四連桿機構的操縱取代了伺服馬達的控制，使其方向永遠指向前方，因此少了一個需要操心的自由度，從而大幅簡化了連桿分析及控制上的複雜度

The+Formability+Index+and+Quality+Evaluation+of+Ca-pectin+Hydrogel+Beads

Low methoxyl pectin and calcium ion have high-viscosity coacervation and are used to prepare jam and hydrogel product. Recently, the microencapsulation technique is quite popular for the production of a compound of pectin and calcium ion and is often used in the health-care, biotech and pharmaceutical field. The compound is usually used as tablet binder, coating agent, drug encapsule, drug delivery carrier, improvement of control release and so on. In this study, we use the low methoxyl pectin as the material to study the formability and quality index of Ca-pectin hydrogel bead treated by different pectin concentrations (2.5, 5.0 and 7.5 %), calcium chloride concentrations (0.05, 0.1, 0.5 and 1.0 M) and curing times (0.5, 5.0 and 20.0 min). The research result showed that the overall wet and dry hydrogel bead have increasing trend in higher completeness, higher hardness, and decreasing trend in less shrinkage, smaller particle size, lower water content and lower swelling capacity along with the increasing in the pectin concentration, calcium ion concentration and curing time. In the thermograms, the increase in the pectin concentration, calcium ion concentration and curing time lead to an increase in the onset temperature (To), peak temperature (Tp) and enthalpy (ΔH). The increased air flow (0~3 L/min) in the compressor would cause the particle size (2.70mm~0.32mm) and swelling capacity (-8.45%~9.0%) of the Ca-hydrogel to decrease. Moreover, there was more shrinking on the surface with more combination of pectin and calcium.低甲氧基果膠與鈣會形成高黏度的凝膠作用，常供果醬及凝膠產品之製備；“鈣化果膠複合物”是保健、生技、製藥界近年十分熱門之微膠囊化技術及材料；其常被應用於錠劑之結著、包覆劑；藥物包埋、輸送及釋放改善等研究。本實驗以低甲氧基果膠為材料，探討果膠（2.5、5.0、7.5%）、氯化鈣（0.05、0.1、0.5、1.0 M）濃度及不同固化時間（0.5、5、20 min）對果膠鈣晶球成型性及各項粒子品質因子分析；實驗結果如下：果膠鈣晶球成型性隨果膠及氯化鈣濃度提高及固化時間延長，整體濕、乾球粒之外型完整性較佳，收縮少；粒徑較小，硬度提高，含水量及膨潤力降低，熱性質項目有較高之起始溫度（To），尖峰溫度（Tp）及熱焓值（ΔH）。另外利用空壓機搭配流量計提高空氣流速（0～3L/min），可製得濕球粒之粒徑（2.70～0.32mm）、膨潤力（-8.45～9.0%），成型較佳之晶球粒子；另隨果膠－鈣結合愈多其外表微細構造有較多收縮之紋路