A CMOS dual-band low noise amplifer (LNA) design is presented.The purpose of th is work is intended to substitute only one LNA for two individual LNA's in dual -band transceivers for applications such as wireless ...A CMOS dual-band low noise amplifer (LNA) design is presented.The purpose of th is work is intended to substitute only one LNA for two individual LNA's in dual -band transceivers for applications such as wireless local area network complying with both IEEE 802.11a and 802.11b/g.Dua l-band simultaneous input power and noise matching and load shaping are discuss ed.The chip is implemented in 0.25μm CMOS mixed and RF process.The measured pe rformance is summarized and discussed.展开更多
In this paper,we present a method for localization of a rail autonomous pesticide spraying and sampling robot working in greenhouse using an absolute localization system.Design and implementation of the localization s...In this paper,we present a method for localization of a rail autonomous pesticide spraying and sampling robot working in greenhouse using an absolute localization system.Design and implementation of the localization system comes from the usage of beacon systems each of which is composed of an RF single receiver and an ultrasonic transmitter.The RF single receiver gets the synchronization signal from the mobile robot,and the ultrasonic transmitter sends ultrasonic signal,thus the distance from the beacon to the ultrasonic receiver can be measured.The position of a beacon in coordinate system of robot can be calculated according to distance information from the beacons to two ultrasonic receivers which are mounted on the robot.Based on the coordinate transformation,the position of a mobile robot can be calculated from the beacon＇s absolute position information in the global coordinate system.Experiments demonstrate the effectiveness of the proposed method in real world applications.展开更多
We consider an iterative phase synchronization scheme based on maximum a posteriori probability algorithm.In classical approaches,the phase noise estimation model considers one sample per symbol at the channel and rec...We consider an iterative phase synchronization scheme based on maximum a posteriori probability algorithm.In classical approaches,the phase noise estimation model considers one sample per symbol at the channel and receiver.However,information theoretic studies suggested use of more than one sample per symbol at the channel and receiver for achieving higher performance.In this article,a soft-information aided iterative receiver is derived,which uses off-the-shelf blocks for detection and demodulation by keeping the complexity of the receiver acceptable.We consider here two samples per symbols at the channel and receiver in a pragmatic paradigm.It is shown that phase noise estimation can be significantly improved at the expense of modest processing overhead.Simulation results are presented for low-density parity check coded quadrature amplitude modulations.Our results show a significant performance improvement for strong phase noise values compared to classical receiver approaches.展开更多
This paper describes a CMOS low noise amplifier （LNA） plus the quadrature mixers intended for use in the front-end of portable global positioning system （GPS） receivers. The LNA makes use of an inductively degener...This paper describes a CMOS low noise amplifier （LNA） plus the quadrature mixers intended for use in the front-end of portable global positioning system （GPS） receivers. The LNA makes use of an inductively degenerated input stage and power-constrained simultaneous noise and input matching techniques. The quadrature mixers are based on a Gil- bert cell type. The circuits are implemented in a TSMC 0.18μm RF CMOS process. Measurement results show that a voltage conversion gain of 35dB is achieved with a cascade noise and an input return loss of - 22.3dB. The fully differential figure of 2.4dB,an input ldB compression point of - 22dBm, circuits only draw 5.4mW from a 1.8V supply.展开更多
A new receiver is proposed, which uses the fiber optical parametric amplifier(FOPA) in optical code division multiple access(OCDMA) over free space optic(FSO) communication system. The noise tolerance as the performan...A new receiver is proposed, which uses the fiber optical parametric amplifier(FOPA) in optical code division multiple access(OCDMA) over free space optic(FSO) communication system. The noise tolerance as the performance index in this receiver is derived. The receiver can not only improve the noise tolerance but also change the pump data conveniently for adapting to the length variation of the coding sequence under a complex and fast-changing weather condition. The influence of different factors on the noise tolerance is analyzed, and a significant improvement of about 18.77 d B for the noise tolerance can be achieved when the pump power and the length of coding sequence are 5 W and 256, respectively.展开更多
文摘A CMOS dual-band low noise amplifer (LNA) design is presented.The purpose of th is work is intended to substitute only one LNA for two individual LNA's in dual -band transceivers for applications such as wireless local area network complying with both IEEE 802.11a and 802.11b/g.Dua l-band simultaneous input power and noise matching and load shaping are discuss ed.The chip is implemented in 0.25μm CMOS mixed and RF process.The measured pe rformance is summarized and discussed.
基金supported by the MKE(The Ministry of Knowledge Economy),Korea,under the ITRC(Information Technology Research Center)support program supervised by the NIPA(National IT Industry Promotion Agency)(NIPA-2010-C1090-1021-0010)
文摘In this paper,we present a method for localization of a rail autonomous pesticide spraying and sampling robot working in greenhouse using an absolute localization system.Design and implementation of the localization system comes from the usage of beacon systems each of which is composed of an RF single receiver and an ultrasonic transmitter.The RF single receiver gets the synchronization signal from the mobile robot,and the ultrasonic transmitter sends ultrasonic signal,thus the distance from the beacon to the ultrasonic receiver can be measured.The position of a beacon in coordinate system of robot can be calculated according to distance information from the beacons to two ultrasonic receivers which are mounted on the robot.Based on the coordinate transformation,the position of a mobile robot can be calculated from the beacon＇s absolute position information in the global coordinate system.Experiments demonstrate the effectiveness of the proposed method in real world applications.
文摘We consider an iterative phase synchronization scheme based on maximum a posteriori probability algorithm.In classical approaches,the phase noise estimation model considers one sample per symbol at the channel and receiver.However,information theoretic studies suggested use of more than one sample per symbol at the channel and receiver for achieving higher performance.In this article,a soft-information aided iterative receiver is derived,which uses off-the-shelf blocks for detection and demodulation by keeping the complexity of the receiver acceptable.We consider here two samples per symbols at the channel and receiver in a pragmatic paradigm.It is shown that phase noise estimation can be significantly improved at the expense of modest processing overhead.Simulation results are presented for low-density parity check coded quadrature amplitude modulations.Our results show a significant performance improvement for strong phase noise values compared to classical receiver approaches.
文摘This paper describes a CMOS low noise amplifier （LNA） plus the quadrature mixers intended for use in the front-end of portable global positioning system （GPS） receivers. The LNA makes use of an inductively degenerated input stage and power-constrained simultaneous noise and input matching techniques. The quadrature mixers are based on a Gil- bert cell type. The circuits are implemented in a TSMC 0.18μm RF CMOS process. Measurement results show that a voltage conversion gain of 35dB is achieved with a cascade noise and an input return loss of - 22.3dB. The fully differential figure of 2.4dB,an input ldB compression point of - 22dBm, circuits only draw 5.4mW from a 1.8V supply.
基金supported by the National Key Basic Research Special Foundation(Nos.2010CB327605 and 2010CB328300)the National Natural Science Foundation of China(No.61307109)+2 种基金the National High Technology Research and Development Program of China(Nos.2013AA031501 and 2013AA013303)the Specialized Research Fund for the Doctoral Program of Higher Education(No.20120005120021)the Fundamental Research Funds for the Central Universities(No.2013RC1202)
文摘A new receiver is proposed, which uses the fiber optical parametric amplifier(FOPA) in optical code division multiple access(OCDMA) over free space optic(FSO) communication system. The noise tolerance as the performance index in this receiver is derived. The receiver can not only improve the noise tolerance but also change the pump data conveniently for adapting to the length variation of the coding sequence under a complex and fast-changing weather condition. The influence of different factors on the noise tolerance is analyzed, and a significant improvement of about 18.77 d B for the noise tolerance can be achieved when the pump power and the length of coding sequence are 5 W and 256, respectively.
