In order to ensure stable,correct and real-time high-speed transmission of indoor visible light communication(VLC),the key modulation and demodulation technologies of orthogonal frequency division multiplexing(OFDM) a...In order to ensure stable,correct and real-time high-speed transmission of indoor visible light communication(VLC),the key modulation and demodulation technologies of orthogonal frequency division multiplexing(OFDM) are studied in this paper. The time-domain synchronization,frequency synchronization and channel equalization of receiver are analyzed and optimized by utilizing short and long training preamble. Moreover,field programmable gate array(FPGA) development board(Xilinx Kintex-7) and Verilog hardware description language are used to realize the design of proposed OFDM-VLC system. Simulation and experiment both verify the feasibility of the hardware designs of this system. The proposed OFDM-based VLC system can process signal in real-time,which can be used in actual VLC application systems.展开更多
提出了一种在数字通信中对接收到未知BPSK或QPSK制式信号进行自动识别的新方法.该方法通过使未知制式信号进入差分处理系统后所得数据进行统计与分析,进而完成对调制信号制式的识别.本文针对加性白噪声信道情况,对这种方法的识别率进行...提出了一种在数字通信中对接收到未知BPSK或QPSK制式信号进行自动识别的新方法.该方法通过使未知制式信号进入差分处理系统后所得数据进行统计与分析,进而完成对调制信号制式的识别.本文针对加性白噪声信道情况,对这种方法的识别率进行了仿真与分析,仿真结果表明:该新方法在信噪比不低于11 d B时正确识别率不低于95%.最后对该识别方法的FPGA设计与实现进行了研究,结果表明这种方法在工程实践中具有很好的实用价值.展开更多
航天飞行器飞行的焰尾对信号的影响很大,针对这个问题,测控系统提出了具有很强抗干扰能力的调频遥测信号。调频遥测信号相干解调需要用到反三角计算,介绍了一种基于FPGA相干解调方法即坐标旋转计算(Coordinate Rotation Digital Compute...航天飞行器飞行的焰尾对信号的影响很大,针对这个问题,测控系统提出了具有很强抗干扰能力的调频遥测信号。调频遥测信号相干解调需要用到反三角计算,介绍了一种基于FPGA相干解调方法即坐标旋转计算(Coordinate Rotation Digital Computer,CORDIC)硬件鉴频算法,同时通过仿真对理论值、计算值与硬件算法的性能进行了比较。结果表明这种算法的性能接近理论值,适用于调频遥测解调。展开更多
介绍了基于UHF Class 1 Generation2协议标准的RFID系统的调制、解调算法。在FPGA上实现了调制器和解调器,调制器可根据用户需要选择DSB-ASK、SSB-ASK或PR-ASK调制方式,解调器能同时解调2ASK和BPSK信号。使用QuartusⅡ与MATLAB联合仿真...介绍了基于UHF Class 1 Generation2协议标准的RFID系统的调制、解调算法。在FPGA上实现了调制器和解调器,调制器可根据用户需要选择DSB-ASK、SSB-ASK或PR-ASK调制方式,解调器能同时解调2ASK和BPSK信号。使用QuartusⅡ与MATLAB联合仿真,结果表明设计的RFID调制器和解调器是正确的。展开更多
基金supported by the National High Technology Research and Development Program of China(863 Program)(No.2015AA033303)the National Key Basic Research Program of China(973 program)(No.2013CB329204)+1 种基金the National Nature Science Foundation of China(Nos.61178051,61321063 and 61335010)the Science and Technology Project of Guangdong Province in China(No.2014B010120004)
文摘In order to ensure stable,correct and real-time high-speed transmission of indoor visible light communication(VLC),the key modulation and demodulation technologies of orthogonal frequency division multiplexing(OFDM) are studied in this paper. The time-domain synchronization,frequency synchronization and channel equalization of receiver are analyzed and optimized by utilizing short and long training preamble. Moreover,field programmable gate array(FPGA) development board(Xilinx Kintex-7) and Verilog hardware description language are used to realize the design of proposed OFDM-VLC system. Simulation and experiment both verify the feasibility of the hardware designs of this system. The proposed OFDM-based VLC system can process signal in real-time,which can be used in actual VLC application systems.
文摘提出了一种在数字通信中对接收到未知BPSK或QPSK制式信号进行自动识别的新方法.该方法通过使未知制式信号进入差分处理系统后所得数据进行统计与分析,进而完成对调制信号制式的识别.本文针对加性白噪声信道情况,对这种方法的识别率进行了仿真与分析,仿真结果表明:该新方法在信噪比不低于11 d B时正确识别率不低于95%.最后对该识别方法的FPGA设计与实现进行了研究,结果表明这种方法在工程实践中具有很好的实用价值.
文摘航天飞行器飞行的焰尾对信号的影响很大,针对这个问题,测控系统提出了具有很强抗干扰能力的调频遥测信号。调频遥测信号相干解调需要用到反三角计算,介绍了一种基于FPGA相干解调方法即坐标旋转计算(Coordinate Rotation Digital Computer,CORDIC)硬件鉴频算法,同时通过仿真对理论值、计算值与硬件算法的性能进行了比较。结果表明这种算法的性能接近理论值,适用于调频遥测解调。
文摘介绍了基于UHF Class 1 Generation2协议标准的RFID系统的调制、解调算法。在FPGA上实现了调制器和解调器,调制器可根据用户需要选择DSB-ASK、SSB-ASK或PR-ASK调制方式,解调器能同时解调2ASK和BPSK信号。使用QuartusⅡ与MATLAB联合仿真,结果表明设计的RFID调制器和解调器是正确的。
