TN249 2003021010激光除锈过程的实时监测技术研究=Real-time monitor- ing technique for laser cleaning rust deposite[刊,中]/徐军(第二炮兵工程学院物理教研室.陕西,西安(710025)),孙振永…//光子学报.—2002,31(9).—1090-1092对...TN249 2003021010激光除锈过程的实时监测技术研究=Real-time monitor- ing technique for laser cleaning rust deposite[刊,中]/徐军(第二炮兵工程学院物理教研室.陕西,西安(710025)),孙振永…//光子学报.—2002,31(9).—1090-1092对激光除锈过程中的实时监测技术进行了实验研究,结果表明:除锈过程中产生的声波强度会随着表面清洁度的变化而发生明显的变化,声波信号包含了除锈过程中的大量信息,可作为激光除锈实时监测的基本信号。图2参9(李瑞琴)展开更多
A new low-cost demodulator for ZigBee receivers satisfying requirements of IEEE802.15.4 standard is presented,which is designed for ISM 2.4 GHz band and based on Zero-IF receivers.This demodulator extracts symbols dir...A new low-cost demodulator for ZigBee receivers satisfying requirements of IEEE802.15.4 standard is presented,which is designed for ISM 2.4 GHz band and based on Zero-IF receivers.This demodulator extracts symbols directly from baseband signal rather than recovering PN code chips,so its structure is simple.Two main techniques are used to improve the performance of demodulator.One is Phase-Axis Crossing Detector(PACD) which detects the phase correlation of baseband signal.The other is symbol synchronization and sampling clock correction algorithm.The result shows that this demodulator performance,Symbol Error Rate(SER) and Packet Error Rate(PER) meet IEEE 802.15.4TM standard requirements and the demodulator can handle frequency offset in excess of 200 kHz,involving a Zero-IF receiver with a Noise Figure(NF) lower than 17 dB,which is easily imple-mented in standard CMOS technology.展开更多
文摘TN249 2003021010激光除锈过程的实时监测技术研究=Real-time monitor- ing technique for laser cleaning rust deposite[刊,中]/徐军(第二炮兵工程学院物理教研室.陕西,西安(710025)),孙振永…//光子学报.—2002,31(9).—1090-1092对激光除锈过程中的实时监测技术进行了实验研究,结果表明:除锈过程中产生的声波强度会随着表面清洁度的变化而发生明显的变化,声波信号包含了除锈过程中的大量信息,可作为激光除锈实时监测的基本信号。图2参9(李瑞琴)
基金Supported by Zhejiang Province Important Sci-Tech Foundation Item (No.2006C11107)
文摘A new low-cost demodulator for ZigBee receivers satisfying requirements of IEEE802.15.4 standard is presented,which is designed for ISM 2.4 GHz band and based on Zero-IF receivers.This demodulator extracts symbols directly from baseband signal rather than recovering PN code chips,so its structure is simple.Two main techniques are used to improve the performance of demodulator.One is Phase-Axis Crossing Detector(PACD) which detects the phase correlation of baseband signal.The other is symbol synchronization and sampling clock correction algorithm.The result shows that this demodulator performance,Symbol Error Rate(SER) and Packet Error Rate(PER) meet IEEE 802.15.4TM standard requirements and the demodulator can handle frequency offset in excess of 200 kHz,involving a Zero-IF receiver with a Noise Figure(NF) lower than 17 dB,which is easily imple-mented in standard CMOS technology.
