Aiming at the application of a wireless sensor network to locating miners in underground mine,we design a wireless sensor network location node system,considering the communication performance and the intrinsic safety...Aiming at the application of a wireless sensor network to locating miners in underground mine,we design a wireless sensor network location node system,considering the communication performance and the intrinsic safety. The location node system consists of a mobile node,several fixed nodes,and a sink node,all of whose circuits were designed based on CC2430. A varistor and a RC circuit were used in the reset circuit of a sensor node to guarantee the intrinsic safety by reducing discharge energy,the theoretical analysis of the discharge energy shows that the reset circuit is an intrinsic safety one. The analysis and simulation about the performance of the location node system are discussed,such as network communication delay and packet loss rate,the results show that the highest network communication delay of the system is about 0.11 seconds,and the highest packet loss rate is about 0.13,which assures the location node system has a high reliability,and can locate miners in the underground mine.展开更多
A programmable transversal equalizer for electronic dispersion compensation(EDC) in optical fiber communication systems is developed.Based on the SiGe technology with a cut-off frequency of 80 GHz,the equalizer consis...A programmable transversal equalizer for electronic dispersion compensation(EDC) in optical fiber communication systems is developed.Based on the SiGe technology with a cut-off frequency of 80 GHz,the equalizer consists of 6 seriesparallel amplifiers as delay units and 7 Gilbert variable gain amplifiers as taps,which ensure that the equalizer can work at the bit rate of 10 Gb/s.With different tap gains,the forward voltage gain of the transversal equalizer varies,which demonstrates that the equalizer has various filtering characteristics such as low pass filtering,band pass filtering,band reject filtering,and notch filtering,so it can effectively simulate the inverse transfer function of dispersive channels in optical communications,and can be used for compensating the inter-symbol interference and other nonlinear problems caused by dispersion.The equalizer(including pads) occupies an area of 0.40 mm × 1.08 mm,and its total power dissipation is 400 mW with 3.3 V power supply.展开更多
基金Projects 20070411065 supported by the China Postdoctoral Science Foundation0801028B by the Jiangsu Postdoctoral Science Research Foundation
文摘Aiming at the application of a wireless sensor network to locating miners in underground mine,we design a wireless sensor network location node system,considering the communication performance and the intrinsic safety. The location node system consists of a mobile node,several fixed nodes,and a sink node,all of whose circuits were designed based on CC2430. A varistor and a RC circuit were used in the reset circuit of a sensor node to guarantee the intrinsic safety by reducing discharge energy,the theoretical analysis of the discharge energy shows that the reset circuit is an intrinsic safety one. The analysis and simulation about the performance of the location node system are discussed,such as network communication delay and packet loss rate,the results show that the highest network communication delay of the system is about 0.11 seconds,and the highest packet loss rate is about 0.13,which assures the location node system has a high reliability,and can locate miners in the underground mine.
基金supported by the Natural Science Foundation of Hebei Province (No.F2008000116)
文摘A programmable transversal equalizer for electronic dispersion compensation(EDC) in optical fiber communication systems is developed.Based on the SiGe technology with a cut-off frequency of 80 GHz,the equalizer consists of 6 seriesparallel amplifiers as delay units and 7 Gilbert variable gain amplifiers as taps,which ensure that the equalizer can work at the bit rate of 10 Gb/s.With different tap gains,the forward voltage gain of the transversal equalizer varies,which demonstrates that the equalizer has various filtering characteristics such as low pass filtering,band pass filtering,band reject filtering,and notch filtering,so it can effectively simulate the inverse transfer function of dispersive channels in optical communications,and can be used for compensating the inter-symbol interference and other nonlinear problems caused by dispersion.The equalizer(including pads) occupies an area of 0.40 mm × 1.08 mm,and its total power dissipation is 400 mW with 3.3 V power supply.
