The method of using multiplexing technique to realize the optically powered multiple detection system is presented. As this system adopted novel time and pulse width multiplexing techniques, reliable separation and er...The method of using multiplexing technique to realize the optically powered multiple detection system is presented. As this system adopted novel time and pulse width multiplexing techniques, reliable separation and error code correcting techniques, it realizes optically powered multiple channel and parameters detection, and successfully applied in the oil tanks for temperature, pressure, liquid level and reserve measurings.展开更多
A new training symbol weighted by pseudo-noise(PN) sequence is designed and an efficient timing and fre-quency offset estimation scheme for orthogonal frequency division multiplexing(OFDM) systems is proposed. The tim...A new training symbol weighted by pseudo-noise(PN) sequence is designed and an efficient timing and fre-quency offset estimation scheme for orthogonal frequency division multiplexing(OFDM) systems is proposed. The timing synchronization is accomplished by using the piecewise symmetric conjugate of the primitive training symbol and the good autocorrelation of PN weighted factor. The frequency synchronization is finished by utilizing the training symbol whose PN weighted factor is removed after the timing synchronization. Compared with conventional schemes, the pro-posed scheme can achieve a smaller mean square error and provide a wider frequency acquisition range.展开更多
Multiplexing techniques have always been one of the important components of optical communication research.These techniques can transmit multiple signals in a shared information channel and can greatly increase the ma...Multiplexing techniques have always been one of the important components of optical communication research.These techniques can transmit multiple signals in a shared information channel and can greatly increase the maximum capacity of an information channel.The Dirac-vortex cavity is a type of photonic crystal surface emission system,and its characteristics of miniaturization and high stability make it very suitable for on-chip optical system.In this paper,we realized dual-channel emission of the Dirac-vortex cavity,which is achieved by modulating the size and phase of hexagonal holes in the hexagon lattice.The characteristics of dual-channel emission are investigated by numerical simulation,and the dual-channel emission rules are summarized.The double Diracvortex cavity model is not only explored for its multiplexing capability but also as an alternative scheme for the application of Dirac-vortex cavity in multiplex communication systems.展开更多
基金This subject is subsidized by Hebei Education Commission
文摘The method of using multiplexing technique to realize the optically powered multiple detection system is presented. As this system adopted novel time and pulse width multiplexing techniques, reliable separation and error code correcting techniques, it realizes optically powered multiple channel and parameters detection, and successfully applied in the oil tanks for temperature, pressure, liquid level and reserve measurings.
基金Supported by the National High Technology Research and Development Program of China ( "863" Program, No.2006AA01Z270)Natural Science Foun-dation of Shaanxi Province (No. 2007F07)+1 种基金Natural Science Foundation of Guangdong Province (No. U0635003)National "111" Program of Intro-ducing Talents of Discipline to Universities (No. B08038)
文摘A new training symbol weighted by pseudo-noise(PN) sequence is designed and an efficient timing and fre-quency offset estimation scheme for orthogonal frequency division multiplexing(OFDM) systems is proposed. The timing synchronization is accomplished by using the piecewise symmetric conjugate of the primitive training symbol and the good autocorrelation of PN weighted factor. The frequency synchronization is finished by utilizing the training symbol whose PN weighted factor is removed after the timing synchronization. Compared with conventional schemes, the pro-posed scheme can achieve a smaller mean square error and provide a wider frequency acquisition range.
基金National Natural Science Foundation of China(12404423,62375007,62405012)Natural Science Foundation of Beijing Municipality(1232024)Applied Basic Research Fund of School of Physics and Optoelectronic Engineering,Beijing University of Technology(ABRFSPOE03).
文摘Multiplexing techniques have always been one of the important components of optical communication research.These techniques can transmit multiple signals in a shared information channel and can greatly increase the maximum capacity of an information channel.The Dirac-vortex cavity is a type of photonic crystal surface emission system,and its characteristics of miniaturization and high stability make it very suitable for on-chip optical system.In this paper,we realized dual-channel emission of the Dirac-vortex cavity,which is achieved by modulating the size and phase of hexagonal holes in the hexagon lattice.The characteristics of dual-channel emission are investigated by numerical simulation,and the dual-channel emission rules are summarized.The double Diracvortex cavity model is not only explored for its multiplexing capability but also as an alternative scheme for the application of Dirac-vortex cavity in multiplex communication systems.
