This paper presents a 10 bit successive approximation register （SAR） analog-to-digital converter （ADC） in 0.18 μm 1P6M CMOS technology with a 1.8 V supply voltage. To improve the conversion speed, a partial split...This paper presents a 10 bit successive approximation register （SAR） analog-to-digital converter （ADC） in 0.18 μm 1P6M CMOS technology with a 1.8 V supply voltage. To improve the conversion speed, a partial split capacitor switching scheme is proposed. By reducing the time constant of the bit cycles, the proposed technique shortens the settling time of a capacitive digital-to-analog converter （DAC）. In addition, a new SAR control logic is proposed to reduce loop delay to further enhance the conversion speed. At 1.8 V supply voltage and 50 MS/s the SAR ADC achieves a signal-to-noise and distortion ratio （SNDR） of 57.5 dB and spurious-free dynamic range （SFDR） of 69.3 dB. The power consumption is 2.26 mW and the core die area is 0.096 mm2.展开更多
A 12-bit intrinsic accuracy digital-to-analog converter integrated into standard digital 0.18μm CMOS technology is proposed. It is based on a current steering segmented 6＋6 architecture and requires no calibration. ...A 12-bit intrinsic accuracy digital-to-analog converter integrated into standard digital 0.18μm CMOS technology is proposed. It is based on a current steering segmented 6＋6 architecture and requires no calibration. By dividing one most significant bit unary source into 16 elements located in 16 separated regions of the array, the linear gradient errors and quadratic errors can be averaged and eliminated effectively. A novel static performance testing method is proposed. The measured differential nonlinearity and integral nonlinearity are 0.42 and 0.39 least significant bit, respectively. For 12-bit resolution, the converter reaches an update rate of 100 MS/s. The chip operates from a single 1.8 V voltage supply, and the core die area is 0.28 mm^2.展开更多
The aircraft engine multi-loop control system is described and the switching control theory is introduced to solve the regulating and protecting control problems in this paper. The aircraft engine multi-loop control s...The aircraft engine multi-loop control system is described and the switching control theory is introduced to solve the regulating and protecting control problems in this paper. The aircraft engine multi-loop control system is firstly described and the control problems are formulated. Secondly, the theory of the smooth switching control is devoted and a new extended scheme for the smooth switching of a switched control system is introduced. Then, for the key technologies of aero-engines switching control, a design algorithm is presented which can determine which candidate controller should be put in feedback with the plant to achieve a desired performance and the procedure to design the aircraft engine multi-loop control system is detailed. The switching performance objectives and the switching scheme are given and a family of PID controllers and compensators is designed. The simulation shows that using the switching control design method can not only improve the dynamic performance of the aircraft engine control system and reduce the switching times, but also guarantee the stability in some peculiar occasions.展开更多
It is well-known that turbo equalization with the max-log-map(MLM)rather than the log-map(LM)algorithm is insensitive to signal to noise ratio(SNR)mismatch.As our first contribution,an improved MLM algorithm called sc...It is well-known that turbo equalization with the max-log-map(MLM)rather than the log-map(LM)algorithm is insensitive to signal to noise ratio(SNR)mismatch.As our first contribution,an improved MLM algorithm called scaled max-log-map(SMLM)algorithm is presented.Simulation results show that the SMLM scheme can dramatically outperform the MLM without sacrificing the robustness against SNR mismatch.Unfortunately,its performance is still inferior to that of the LM algorithm with exact SNR knowledge over the class of high-loss channels.As our second contribution,a switching turbo equalization scheme,which switches between the SMLM and LM schemes,is proposed to practically close the performance gap.It is based on a novel way to estimate the SNR from the reliability values of the extrinsic information of the SMLM algorithm.展开更多
This paper presents an energy efficient successive-approximation register(SAR)analog-to-digital converter(ADC)for low-power applications.To improve the overall energy-efficiency,a skipping-window technique is used to ...This paper presents an energy efficient successive-approximation register(SAR)analog-to-digital converter(ADC)for low-power applications.To improve the overall energy-efficiency,a skipping-window technique is used to bypass corresponding conversion steps when the input falls in a window indicated by a time-domain comparator,which can provide not only the polarity of the input,but also the amount information of the input.The timedomain comparator,which is based on the edge pursing principle,consists of delay cells,two NAND gates,two D-flip-flop register-based phase detectors and a counter.The digital characteristic of the comparator makes the design more flexible,and the comparator can achieve noise and power optimization automatically by simply adjusting the delay cell number.An energy efficient digital-to-analog converter(DAC)control scheme suitable for the skipping window technique is also developed to reduce the switching energy during SAR conversion.Together with the skipping-window technique,the linearity and the power consumption of the SAR ADC are improved.The impact of different window sizes on comparison cycles,DAC switching energy and the overall energy efficiency is analyzed.Simulation results show that the proposed skipping-window technique can improve the overall energy-efficiency of the SAR ADC,as well as the linearity,and the optimized window size for the overall energy efficiency will vary with the DAC switching energy.展开更多
This paper concentrates on enhancing the productivity of the multilevel inverter and nature of yield voltage waveform. Seven level lessened switches topology has been actualized with just seven switches. Essential Swi...This paper concentrates on enhancing the productivity of the multilevel inverter and nature of yield voltage waveform. Seven level lessened switches topology has been actualized with just seven switches. Essential Switching plan and Selective Harmonics Elimination were executed to diminish the Total Harmonics Distortion (THD) esteem. Selective Harmonics Elimination Stepped Waveform (SHESW) strategy is executed to dispense with the lower order harmonics. Fundamental switching plan is utilized to control the switches in the inverter. The proposed topology is reasonable for any number of levels. The harmonic lessening is accomplished by selecting fitting switching angles. It indicates would like to decrease starting expense and unpredictability consequently it is able for modern applications. In this paper, third and fifth level harmonics have been disposed of. Simulation work is done utilizing the MATLAB/Simulink programming results have been displayed to accept the hypothesis.展开更多
The traditional communication system is effectively designed for the worst-case channel state and it can not use the spectral efficiently over the time-varying multipath channel. In order to improve the spectral effic...The traditional communication system is effectively designed for the worst-case channel state and it can not use the spectral efficiently over the time-varying multipath channel. In order to improve the spectral efficiency and ensure robust and spectrally-efficient transmission over the time-varying multipath channel,a joint rate control and adaptive modulation and coding ( AMC) algorithm for adaptive transmission systems is proposed in this paper. Firstly,the proposed algorithm can formulate a modulation and coding scheme ( MCS) switching table according to the offline simulation results and the target bit error rate ( BER) . Then,the optimal MCS is selected in MCS switching table according to the channel state information ( CSI) and then passes to the transmitter and receiver to implement. So the adaptive system which always uses the optimal MCS to transmit signals uses the spectral efficiently. The simulation results validate the proposed algorithm and show that under the premise of meeting the target BER,the adaptive system performing the proposed algorithm has a higher average spectral efficiency ( ASE) than that of the non-adaptive system.展开更多
An optical burst switching （OBS） network platform is established with a ring topology of three nodes. A congestion Mleviated scheme using advanced token protocol and wavelength tunable receivers is demon- strated to...An optical burst switching （OBS） network platform is established with a ring topology of three nodes. A congestion Mleviated scheme using advanced token protocol and wavelength tunable receivers is demon- strated to optimize the network platform. Experimental results testify that this scheme can resist collision at the level of 0.1% congestion rate.展开更多
Optics is a potential candidate in information, data, and image processing. In all-optical data and information processing, optics has been used as information carrying signal because of its inherent advantages of par...Optics is a potential candidate in information, data, and image processing. In all-optical data and information processing, optics has been used as information carrying signal because of its inherent advantages of parallelism. Several optical methods are proposed in support of the above processing. In many algebraic, arithmetic, and image processing schemes fundamental logic and memory operations are conducted exploring all-optical devices. In this communication we report an all-optical matrix multiplication operation with non-linear material based switching circuit.展开更多
A new integrated scheme based on resource-reservation and adaptive network flow routing to alleviate contention in optical burst switching networks is proposed. The objective of the proposed scheme is to reduce the ov...A new integrated scheme based on resource-reservation and adaptive network flow routing to alleviate contention in optical burst switching networks is proposed. The objective of the proposed scheme is to reduce the overall burst loss in the network and at the same time to avoid the packet out-of-sequence arrival problem. Simulations are carried out to assess the feasibility of the proposed scheme. Its performance is compared with that of contention resolution schemes based on conventional routing. Through extensive simulations, it is shown that the proposed scheme not only provides significantly better burst loss performance than the basic equal proportion and hop-length based traffic routing algorithms, but also is void of any packet re-orderings.展开更多
In this letter, we analyze the drawback of tail-dropping contention resolution in optical burst switched networks. Once contention occurs, we adopt modified head-dropping policy to resolve contention. This policy drop...In this letter, we analyze the drawback of tail-dropping contention resolution in optical burst switched networks. Once contention occurs, we adopt modified head-dropping policy to resolve contention. This policy drops the head of the contending burst only if the overlapping region of the two bursts is less than the whole contending burst size, otherwise drops the whole contending burst. In order to have a better support of differentiated service, a new burst assembly policy, namely, Priority-based proportional mixed burst assembly, is proposed. Simulation results show that the proposed scheme performs very well in terms of performance metrics such as the times of contention and packet loss probability.展开更多
基金supported by the National Natural Science Foundation of China(No.61401097)
文摘This paper presents a 10 bit successive approximation register （SAR） analog-to-digital converter （ADC） in 0.18 μm 1P6M CMOS technology with a 1.8 V supply voltage. To improve the conversion speed, a partial split capacitor switching scheme is proposed. By reducing the time constant of the bit cycles, the proposed technique shortens the settling time of a capacitive digital-to-analog converter （DAC）. In addition, a new SAR control logic is proposed to reduce loop delay to further enhance the conversion speed. At 1.8 V supply voltage and 50 MS/s the SAR ADC achieves a signal-to-noise and distortion ratio （SNDR） of 57.5 dB and spurious-free dynamic range （SFDR） of 69.3 dB. The power consumption is 2.26 mW and the core die area is 0.096 mm2.
基金Project supported by the National High Technology Research and Development Program of China(No.2008AA010700)
文摘A 12-bit intrinsic accuracy digital-to-analog converter integrated into standard digital 0.18μm CMOS technology is proposed. It is based on a current steering segmented 6＋6 architecture and requires no calibration. By dividing one most significant bit unary source into 16 elements located in 16 separated regions of the array, the linear gradient errors and quadratic errors can be averaged and eliminated effectively. A novel static performance testing method is proposed. The measured differential nonlinearity and integral nonlinearity are 0.42 and 0.39 least significant bit, respectively. For 12-bit resolution, the converter reaches an update rate of 100 MS/s. The chip operates from a single 1.8 V voltage supply, and the core die area is 0.28 mm^2.
基金supported by the National Natural Science Foundation of China (Grant No. 61104146/F030203)Innovation Plan of Aero Engine Complex System Safety by the Ministry of Education Chang Jiang Scholars of China (Grant No. IRT0905)
文摘The aircraft engine multi-loop control system is described and the switching control theory is introduced to solve the regulating and protecting control problems in this paper. The aircraft engine multi-loop control system is firstly described and the control problems are formulated. Secondly, the theory of the smooth switching control is devoted and a new extended scheme for the smooth switching of a switched control system is introduced. Then, for the key technologies of aero-engines switching control, a design algorithm is presented which can determine which candidate controller should be put in feedback with the plant to achieve a desired performance and the procedure to design the aircraft engine multi-loop control system is detailed. The switching performance objectives and the switching scheme are given and a family of PID controllers and compensators is designed. The simulation shows that using the switching control design method can not only improve the dynamic performance of the aircraft engine control system and reduce the switching times, but also guarantee the stability in some peculiar occasions.
基金This work was supported by the National Nature Science Foundation of China under Grant No.60496313,60502010,and 60602008.
文摘It is well-known that turbo equalization with the max-log-map(MLM)rather than the log-map(LM)algorithm is insensitive to signal to noise ratio(SNR)mismatch.As our first contribution,an improved MLM algorithm called scaled max-log-map(SMLM)algorithm is presented.Simulation results show that the SMLM scheme can dramatically outperform the MLM without sacrificing the robustness against SNR mismatch.Unfortunately,its performance is still inferior to that of the LM algorithm with exact SNR knowledge over the class of high-loss channels.As our second contribution,a switching turbo equalization scheme,which switches between the SMLM and LM schemes,is proposed to practically close the performance gap.It is based on a novel way to estimate the SNR from the reliability values of the extrinsic information of the SMLM algorithm.
基金This work was supported partly by the National Natural Science Foundation of China under Grant No.61704015the General program of Chongqing Natural Science Foundation(a special program for the fundamental and frontier research)under Grant No.cstc2019jcyj-msxmX0108.
文摘This paper presents an energy efficient successive-approximation register(SAR)analog-to-digital converter(ADC)for low-power applications.To improve the overall energy-efficiency,a skipping-window technique is used to bypass corresponding conversion steps when the input falls in a window indicated by a time-domain comparator,which can provide not only the polarity of the input,but also the amount information of the input.The timedomain comparator,which is based on the edge pursing principle,consists of delay cells,two NAND gates,two D-flip-flop register-based phase detectors and a counter.The digital characteristic of the comparator makes the design more flexible,and the comparator can achieve noise and power optimization automatically by simply adjusting the delay cell number.An energy efficient digital-to-analog converter(DAC)control scheme suitable for the skipping window technique is also developed to reduce the switching energy during SAR conversion.Together with the skipping-window technique,the linearity and the power consumption of the SAR ADC are improved.The impact of different window sizes on comparison cycles,DAC switching energy and the overall energy efficiency is analyzed.Simulation results show that the proposed skipping-window technique can improve the overall energy-efficiency of the SAR ADC,as well as the linearity,and the optimized window size for the overall energy efficiency will vary with the DAC switching energy.
文摘This paper concentrates on enhancing the productivity of the multilevel inverter and nature of yield voltage waveform. Seven level lessened switches topology has been actualized with just seven switches. Essential Switching plan and Selective Harmonics Elimination were executed to diminish the Total Harmonics Distortion (THD) esteem. Selective Harmonics Elimination Stepped Waveform (SHESW) strategy is executed to dispense with the lower order harmonics. Fundamental switching plan is utilized to control the switches in the inverter. The proposed topology is reasonable for any number of levels. The harmonic lessening is accomplished by selecting fitting switching angles. It indicates would like to decrease starting expense and unpredictability consequently it is able for modern applications. In this paper, third and fifth level harmonics have been disposed of. Simulation work is done utilizing the MATLAB/Simulink programming results have been displayed to accept the hypothesis.
基金Sponsored by the National Natural Science Foundation and Civil Aviation Administration of China(Grant No.61101122 and 61071104)the Science and Technology on Information Transmission and Dissemination in Communication Networks Laboratory(Grant No.ITD-U12004/K1260010)
文摘The traditional communication system is effectively designed for the worst-case channel state and it can not use the spectral efficiently over the time-varying multipath channel. In order to improve the spectral efficiency and ensure robust and spectrally-efficient transmission over the time-varying multipath channel,a joint rate control and adaptive modulation and coding ( AMC) algorithm for adaptive transmission systems is proposed in this paper. Firstly,the proposed algorithm can formulate a modulation and coding scheme ( MCS) switching table according to the offline simulation results and the target bit error rate ( BER) . Then,the optimal MCS is selected in MCS switching table according to the channel state information ( CSI) and then passes to the transmitter and receiver to implement. So the adaptive system which always uses the optimal MCS to transmit signals uses the spectral efficiently. The simulation results validate the proposed algorithm and show that under the premise of meeting the target BER,the adaptive system performing the proposed algorithm has a higher average spectral efficiency ( ASE) than that of the non-adaptive system.
基金National Natural Science Foundation of China(No.90704006,60572021,and 60711140087)National"973"Program of China(No.2007CB310705)+3 种基金National"863"Project of China(No.2006AA01Z238)PCSIRT(No.IRT0609)ISTCP(No.2006DFAl1040)111 Project(No.B07005).
文摘An optical burst switching （OBS） network platform is established with a ring topology of three nodes. A congestion Mleviated scheme using advanced token protocol and wavelength tunable receivers is demon- strated to optimize the network platform. Experimental results testify that this scheme can resist collision at the level of 0.1% congestion rate.
文摘Optics is a potential candidate in information, data, and image processing. In all-optical data and information processing, optics has been used as information carrying signal because of its inherent advantages of parallelism. Several optical methods are proposed in support of the above processing. In many algebraic, arithmetic, and image processing schemes fundamental logic and memory operations are conducted exploring all-optical devices. In this communication we report an all-optical matrix multiplication operation with non-linear material based switching circuit.
文摘A new integrated scheme based on resource-reservation and adaptive network flow routing to alleviate contention in optical burst switching networks is proposed. The objective of the proposed scheme is to reduce the overall burst loss in the network and at the same time to avoid the packet out-of-sequence arrival problem. Simulations are carried out to assess the feasibility of the proposed scheme. Its performance is compared with that of contention resolution schemes based on conventional routing. Through extensive simulations, it is shown that the proposed scheme not only provides significantly better burst loss performance than the basic equal proportion and hop-length based traffic routing algorithms, but also is void of any packet re-orderings.
基金This work was partially supported by the National Natural Science Foundation of China under Grant No. 69990540.
文摘In this letter, we analyze the drawback of tail-dropping contention resolution in optical burst switched networks. Once contention occurs, we adopt modified head-dropping policy to resolve contention. This policy drops the head of the contending burst only if the overlapping region of the two bursts is less than the whole contending burst size, otherwise drops the whole contending burst. In order to have a better support of differentiated service, a new burst assembly policy, namely, Priority-based proportional mixed burst assembly, is proposed. Simulation results show that the proposed scheme performs very well in terms of performance metrics such as the times of contention and packet loss probability.
