共查询到19条相似文献,搜索用时 109 毫秒
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对QAM解调技术进行了介绍,设计了一种新的QAM解调器,支持16QAM解调和64QAM解调,可应用于手机电视终端,硬件实现简单,节省了系统总体成本. 相似文献
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光纤光栅传感系统模型及其关联解调理论 总被引:3,自引:3,他引:0
提出了光纤光栅传感系统的反射式与透射式物理模型,阐述了其运作机制。引进关联概念,定义了信号关联函数,初步建立了光纤光栅传感系统的关联解调理论。根据该关联解调理论,提出了解调系统的新式分类方法,进而分析、阐述了线性解调、类δ解调和干涉解调3类典型的关联解调系统。 相似文献
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为了进一步研究2PSK非相干解调方案在完整的调制解调系统中的实用性,设计了基于差分相干解调的2DPSK和基于非相干解调的2PSK两种调制解调系统,利用Matlab/Simulink下的系统级设计工具DSP Builder,对两种调制解调系统进行建模与仿真,仿真结果验证了设计的正确性.将两种系统在逻辑资源为百万门的Cyclone II系列FPGA芯片EP2C35F672C6上进行实现,对两种系统的硬件实现性能进行对比分析,结果显示,基于非相干解调的2PSK调制解调系统在资源占用率和处理速度方面具有更优良的性能. 相似文献
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光纤光栅传感器信号解调方法的研究 总被引:4,自引:1,他引:4
分别介绍了几种典型解调方法的工作原理、性能和特点,给出了其工作原理图,并对各种解调方法的优缺点进行了论述.提出了一种基于CCD的光纤光栅传感解调系统,该系统采用反射式成像系统,用CCD作为探测器,并利用可编程逻辑器件FPGA设计驱动电路和信号处理电路,实现了一种体积小、结构简单、解调速度快、可以实时测量的波长解调系统,为光纤光栅解调技术的实际应用和光纤光栅传感解调系统的设计提供了理论依据. 相似文献
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本文针对计算机串行异步通讯解调电路中所存在的问题,提出了一种自动跟踪解调方法,即接收方在解调时可不必设置波特率,而自动适应发送方的调制信号,并对其进行解调,从而提高了解调的准确性和兼容性,同时简化和省去了有关的解调电路,并以kansascity标准(以下简称K.C标准)为例,论述了其工作原理和设计方法。 相似文献
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QPSK中频全数字解调器的研究与FPGA实现 总被引:1,自引:0,他引:1
基于QPSK调制方式的高效率、低误码率、频谱性能好等特点,本文采用可编程逻辑器件CycloneⅡEP2C70F896C6N成功地实现了QPSK全数字解调的电路的设计。分别在MATLAB软件和Quartus Ⅱ9.0软件中进行了解调器中的核心模块的设计和仿真,同时在各个模块仿真成功的情况下,对整体电路进行了仿真。输入端的信号都为20MHz的中频已调信号,最后准确解调出基带信号。通过比较Quartus II仿真结果和MATLAB仿真结果,解调出来的结果是一致的,这也说明了所设计的解调模块是正确的。在信噪比为10dB时,误码率达到10-3,显然电路的设计能够达到要求的性能指标。 相似文献
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给出了高频RFID标签芯片解调电路的设计。设计工艺采用中芯国际(SMIC)2P3M 0.35μm混合信号CMOS技术,并给出了spectre仿真环境下的仿真结果。晶体管级仿真和版图后仿真结果表明所设计电路满足高频RFID标签芯片解调要求。 相似文献
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A. Arcidiacono S. de Vita 《International Journal of Satellite Communications and Networking》1988,6(2):189-196
This paper analyzes the critical areas in optical communications systems, placing particular emphasis on the modulation/demodulation techniques used in the ISL communications subsystem design for the ESA/PSDE programme. A 4-PPM/QPM demodulator has been designed, and problems of implementing the system at high data rates have been addressed. Maximum likelihood demodulation techniques and slot and frame synchronization were used. An attempt was made to devise a way to achieve synchronization tracking without using unique words along data patterns. Finally, for the optical ISL the use of coding is suggested as a way to relax link budget requirements. Coding could reduce problems caused by pointing subsystem instabilities. The use of on-board soft decoding without system bandwidth expansion is also foreseen. 相似文献
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卫星移动通信系统星间链路设计 总被引:2,自引:0,他引:2
通过对现有的卫星移动通信系统星间链路的分析发现 ,不但卫星移动通信系统星间链路的指向具有周期性变化的特性 ,而且星间链路的相对距离也在周期性变化。这种星间链路指向的周期性规律变化 ,为星间通信链路的搜索建立以及星间通信设备的设计制造提供了研究的方向和理论依据。对星间链路的误码率的分析 ,主要探讨了由于卫星星体振动而引起的通信误码与振动的标准偏差 (幅度 )、通信所使用的光波波长、发射到接收的距离以及激光波束半径之间的关系 ,为实际星间链路的设计打下了坚实的理论基础。 相似文献
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Werner M. Delucchi C. Vogel H.-J. Maral G. De Ridder J.-J. 《Selected Areas in Communications, IEEE Journal on》1997,15(1):69-82
An asynchronous transfer mode (ATM)-based concept for the routing of information in a low Earth orbit/medium Earth orbit (LEO/MEO) satellite system including intersatellite links (ISLs) is proposed. Specific emphasis is laid on the design of an ATM-based routing scheme for the ISL part of the system. The approach is to prepare a virtual topology by means of virtual path connections (VPCs) connecting all pairs of end nodes in the ISL subnetwork for a complete period in advance, similar to implementing a set of (time dependent) routing tables. The search for available end-to-end routes within the ISL network is based on a modified Dijkstra (1959) shortest path algorithm (M-DSPA) capable of coping with the time-variant topology. With respect to the deterministic time variance of the considered ISL topologies, an analysis of optimization aspects for the selection of a path at call setup time is presented. The performance of the path search in combination with a specific optimization procedure is-by means of extensive simulations-evaluated for example LEO and MEO ISL topologies, respectively 相似文献
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针对支持多协议的13.56 MHz RFID读卡器芯片解调电路的设计,给出一些关键电路的设计考虑.从读卡器结构入手,先介绍了支持多种协议的读卡器芯片解调电路的设计难点,然后对解调电路设计中的关键部分,提出了设计方法.最后,对流片结果进行了验证. 相似文献
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A. Puccio E. Saggese C. Soprano 《International Journal of Satellite Communications and Networking》1988,6(2):107-117
The intersatellite link (ISL) concept has been under evaluation for many years. It has been the subject of various European Space Agency studies, one of which is summarized here.1 The study was aimed at:
- 1 outlining a reference scenario for satellite communications in the period 1996–2005, when a new satellite generation (Eutelsat III) is expected to be operational in Europe;
- 2 analysing, within the above scenario, the opportunities for an ISL implementation;
- 3 performing a deep system analysis of the selected study cases in order to give the requirements for the first ISL generation;
- 4 evaluating a micro/millimetre wave implementation of the ISL;
- 5 evaluating an optical implementation of the ISL;
- 6 evaluating the technical and economic viability of an ISL and suggesting the best technique to be used in the first ISL generation.