波長信號的解調是實現光纖光柵傳感網絡的關鍵，基于現有的光纖光柵傳感器解調方法，提出一種基于FPGA的雙匹配光纖光柵解調方法，此系統是一種高速率、高精度、低成本的解調系統，并且通過引入雙匹配光柵有效地克服了雙值問題同時擴大了檢測范圍。分析了光纖光柵的測溫原理并給出了該方案軟硬件設計，綜合考慮系統的解調精度和FPGA的處理速度給出了基于拉格朗日的曲線擬合算法。
Abstract:
Sensor is one of the most important application of the fiber grating. Wavelength signal demodulating is the key techniques to carry out fiber grating sensing network， based on several existing methods of fiber grating sensor demodulatIOn inadequate， a two-match fiber grating demodulatIOn method was presented. This system is a high-speed， high precision， low-cost demodulatIOn system. And by introducing a two-match grating effectively overcomes the problem of double value while expands the scope of testing. This paper analyzes the principle of fiber Bragg grating temperature and gives the software and hardware design of the program. Considering the system of demodulatIOn accuracy and processing speed of FPGA，this paper gives the curve fitting algorithm based on Lagrange.
針對傳統集成電路（ASIC）功能固定、升級困難等缺點，利用FPGA實現了擴頻通信芯片STEL-2000A的核心功能。使用ISE提供的DDS IP核實現NCO模塊，在下變頻模塊調用了硬核乘法器并引入CIC濾波器進行低通濾波，給出了DQPSK解調的原理和實現方法，推導出一種簡便的引入?仔/4固定相移的實現方法。采用模塊化的設計方法使用VHDL語言編寫出源程序，在Virtex-II Pro 開發板上成功實現了整個系統。測試結果表明該系統正確實現了STEL-2000A的核心功能。
Abstract:
To overcome drawbacks of ASIC such as fixed functionality and upgrade difficulty, FPGA was used to realize the core functions of STEL-2000A. This paper used the DDS IP core provided by ISE to realize the NCO module, called hard core multiplier and implemented CIC filter in the down converter, described the principle and implementation detail of the demodulatIOn of DQPSK, and derived a simple method to introduce a fixed phase shift of ?仔/4. The VHDL source code was designed by modularity method , and the complete system was successfully implemented on Virtex-II Pro development board. Test results indicate that this system successfully realize the core function of the STEL-2000A.
為了在CDMA系統中更好地應用QDPSK數字調制方式，在分析四相相對移相（QDPSK)信號調制解調原理的基礎上，設計了一種QDPSK調制解調電路，它包括串并轉換、差分編碼、四相載波產生和選相、相干解調、差分譯碼和并串轉換電路。在MAX+PLUSⅡ軟件平臺上，進行了編譯和波形仿真。綜合后下載到復雜可編程邏輯器件EPM7128SLC84-15中，測試結果表明，調制電路能正確選相，解調電路輸出數據與QDPSK調制輸入數據完全一致，達到了預期的設計要求。
Abstract:
In order to realize the better application of digital modulation mode QDPSK in the CDMA system， a sort of QDPSK modulation-demodulatIOn circuit was designed based on the analysis of QDPSK signal modulation-demodulatIOn principles. It included serial/parallel conversion circuit, differential encoding circuit, four-phase carrier wave produced and phase chosen circuit, coherent demodulatIOn circuit, difference decoding circuit and parallel/serial conversion circuit. And it was compiled and simulated on the MAX+PLUSⅡ software platform,and downloaded into the CPLD of EPM7128SLC84-15.The test result shows that the modulation circuit can exactly choose the phase，and the output data of the demodulator circuit is the same as the input data of the QDPSK modulate. The circuit achieves the prospective requirement of the design.
波長信號的解調是實現光纖光柵傳感網絡的關鍵，基于現有的光纖光柵傳感器解調方法，提出一種基于FPGA的雙匹配光纖光柵解調方法，此系統是一種高速率、高精度、低成本的解調系統，并且通過引入雙匹配光柵有效地克服了雙值問題同時擴大了檢測范圍。分析了光纖光柵的測溫原理并給出了該方案軟硬件設計，綜合考慮系統的解調精度和FPGA的處理速度給出了基于拉格朗日的曲線擬合算法。
Abstract:
Sensor is one of the most important application of the fiber grating. Wavelength signal demodulating is the key techniques to carry out fiber grating sensing network， based on several existing methods of fiber grating sensor demodulatIOn inadequate， a two-match fiber grating demodulatIOn method was presented. This system is a high-speed， high precision， low-cost demodulatIOn system. And by introducing a two-match grating effectively overcomes the problem of double value while expands the scope of testing. This paper analyzes the principle of fiber Bragg grating temperature and gives the software and hardware design of the program. Considering the system of demodulatIOn accuracy and processing speed of FPGA，this paper gives the curve fitting algorithm based on Lagrange.
The Hilbert Transform is an important component in communication systems, e.g. for single sideband modulation/demodulatIOn, amplitude and phase detection, etc. It can be formulated as filtering operation which makes it possible to approximate the Hilbert Transform with a digital filter. Due to the non-causal and infinite impulse response of that filter, it is not that easy to get a good approximation with low hardware resource usage. Therefore, different filters with different complexities have been implemented.
The detailed discussion can be found in "Digital Hilbert Transformers or FPGA-based Phase-Locked Loops" (http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=4629940).
The design is fully pipelined for maximum throughput.
This is a superheterodyne reciever simulation, created in MATLAB - Simulink. The purpose is to study the effect of perturbations on the imaginary frequence and on the intermmediate frequence, in the context of incoherent demodulatIOn.
有多徑信道、多普勒頻移，瑞利、RICE(萊斯)信道等仿真，QPSK調制和解調等，交織編碼。程序經過本人測試，絕對可用，并附上本人測試說明和仿真圖像結果-I collected information on 2, how-path channel, Doppler frequency shift, Rayleigh, RICE (Rice) channel, such as simulation, QPSK modulation and demodulatIOn, etc., Interleaved Coded. After I tested the procedure is absolutely available, along with my test images and simulation results indicate.
調制解調課程設計 16QAM調制解調代碼。包括星座圖，頻譜分析，誤碼率分析。-16QAM modulation and demodulatIOn curriculum design code modulation and demodulatIOn. Including constellation, spectrum analysis, bit error rate analysis.
Optical communication technology has been extensively developed over the
last 50 years, since the proposed idea by Kao and Hockham [1]. However, only
during the last 15 years have the concepts of communication foundation, that
is, the modulation and demodulatIOn techniques, been applied. This is pos-
sible due to processing signals using real and imaginary components in the
baseband in the digital domain. The baseband signals can be recovered from
the optical passband region using polarization and phase diversity tech-
niques, as well as technology that was developed in the mid-1980s.
T
his book covers basic communications theory and practical imple-
mentation of transmitters and receivers. In so doing, I focus on dig-
ital modulation, demodulatIOn methods, probabilities, detection of
digital signals, and spread spectrum system design and analysis. This book
was written for those who want a good understanding of the basic prin-
ciples of digital wireless communication systems, including spread spec-
trum techniques. This book also provides a good intuitive and practical
approach to digital communications. Therefore it is a valuable resource for
anyoneinvolvedinwirelesscommunicationsandtransceiverdesignfordig-
ital communications. The reader will gain a broad understanding of basic
communication principles for transceiver design, digital communications,
and spread spectrum, along with examples of many types of commercial
and military data link systems.
