本文研究了基于1-比特模数转换器(Analog to Digital Converters,ADCs)的大规模多输入多输出(Multiple Input Multiple Output,MIMO)系统上行链路的多用户频率同步问题,其中多个单天线用户与配置大规模天线阵列的基站采用正交频分复用(O...本文研究了基于1-比特模数转换器(Analog to Digital Converters,ADCs)的大规模多输入多输出(Multiple Input Multiple Output,MIMO)系统上行链路的多用户频率同步问题,其中多个单天线用户与配置大规模天线阵列的基站采用正交频分复用(Orthogonal Frequency Division Multiplexing,OFDM)技术进行通信.针对多用户角度不重叠的场景,本文利用接收波束成形网络进行多用户干扰消除,从混叠的多用户信号中提取出目标用户的信息,进而对载波频偏(Carrier Frequency Offset,CFO)进行估计.其次,考虑1-比特ADC导致的量化噪声对系统性能的影响,理论推导了基站接收端处的信噪比(Signal-Noise Ratio,SNR).为了提升系统的性能,基于理论SNR对波束成形网络进行了优化设计.最后,计算机仿真结果显示了所提出的频偏估计算法与其他现有算法相比具有更好的性能.展开更多
针对飞卫星姿态确定和控制系统(attitude determination and control system,ADCS)中,IGRF地磁场模型的计算复杂度高和存储空间量大的问题,设计了均匀采样和K曲率加权2种历表模型。首先,给出了均匀历表模型的软件流程、存储格式、轨道...针对飞卫星姿态确定和控制系统(attitude determination and control system,ADCS)中,IGRF地磁场模型的计算复杂度高和存储空间量大的问题,设计了均匀采样和K曲率加权2种历表模型。首先,给出了均匀历表模型的软件流程、存储格式、轨道推演方法;然后,采用U曲率计算方法求解地磁场数据的离散曲率,并提出了K曲率加权方法设计非均匀历表模型;最后,比较了均匀采样和非均匀方法对原曲线的拟合程度,以及在ADCS中应用结果的比较。最终设计了适用于飞卫星的80点基于K曲率加权的非均匀历表模型,仅需0.96 kB存储空间,证明在计算速度和存储空间等方面和现有技术相比具有较大优势。展开更多
This paper presents a fully-differential CMOS dynamic comparator for use in high-speed pipelined ADCs with low stage resolution. Because the architecture is based on the coupled current sources and differential input ...This paper presents a fully-differential CMOS dynamic comparator for use in high-speed pipelined ADCs with low stage resolution. Because the architecture is based on the coupled current sources and differential input pairs, this comparator＇s threshold voltage can be adjusted to a desired level. Compared with traditional comparators, this one shows significant improvement in area,power,and speed. Fabricated in 0.35μm CMOS technology,it occupies only 30μm × 70μm. Simulation and measurement results indicate the comparator has a sampling frequency up to 1GHz with 2Vpp differential input signal range and only 181μW power consumption under a 3.3V supply. The speed/power ratio reaches up to 5524GS/J.展开更多
In a millimeter-wave(mmWave)Massive multiple-input multiple-output(MIMO)systems,full-digital beamforming(i.e.,connecting each antenna with a specific radio-frequency(RF)chain)becomes inefficient due to the hardware co...In a millimeter-wave(mmWave)Massive multiple-input multiple-output(MIMO)systems,full-digital beamforming(i.e.,connecting each antenna with a specific radio-frequency(RF)chain)becomes inefficient due to the hardware cost and power consumption.Therefore,hybrid analog and digital transceiver where the number of RF chains are much smaller than that of the antennas has drawn great research interest.In this work,we investigate the use of low-resolution analog-to-digital converters(ADCs)in the uplink of multi-user hybrid and full-digital mmWave Massive MIMO systems.To be specific,we compare the performance of full-digital minimum mean square error(MMSE)and hybrid MMSE beamforming in both sum rates and energy efficiency.Accurate approximations of sum rates and energy efficiency are provided for both schemes,which captures the dominant factors.The analytical results show that full-digital beamforming outperforms hybrid beamforming in terms of sum rates and requires only a small portion(γ)of antennas used by hybrid beamforming to achieve the same sum rates.We given sufficient condition for full-digital beamforming to outperform hybrid beamforming in terms of energy efficiency.Moreover,an algorithm is proposed to search for the optimal ADC resolution bits.Numerical results demonstrate the correctness of the analysis.展开更多
A reconfigurable intelligent surface(RIS)aided massive multiple-input multiple-output(MIMO)system is considered,where the base station employs a large antenna array with low-cost and low-power 1-bit analog-to-digital ...A reconfigurable intelligent surface(RIS)aided massive multiple-input multiple-output(MIMO)system is considered,where the base station employs a large antenna array with low-cost and low-power 1-bit analog-to-digital converters(ADCs).To compensate for the per-formance loss caused by the coarse quantization,oversampling is applied at the receiver.The main challenge for the acquisition of cascaded channel state information in such a system is to handle the distortion caused by the 1-bit quantization and the sample correlation caused by oversampling.In this work,Bussgang decomposition is applied to deal with the coarse quantization,and a Markov chain is developed to char-acterize the banded structure of the oversampling filter.An approximate message-passing based algorithm is proposed for the estimation of the cascaded channels.Simulation results demonstrate that our proposed 1-bit systems with oversampling can approach the 2-bit systems in terms of the mean square error performance while the former consumes much less power at the receiver.展开更多
A domain extension algorithm to correct the comparator offsets of pipeline analog-to-digital converters (ADCs) is presented, in which the 1.5-bit/stage ADC quantify domain is extended from a three-domain to a five-dom...A domain extension algorithm to correct the comparator offsets of pipeline analog-to-digital converters (ADCs) is presented, in which the 1.5-bit/stage ADC quantify domain is extended from a three-domain to a five-domain. This algorithm is designed for high speed and low comparator accuracy application. The comparator offset correction ability is improved. This new approach also promises significant improvements to the spurious-free dynamic range (SFDR), the total harmonic distortion (THD), the signal-to-noise ratio (SNR) and the minor analog and digital circuit modifications. Behavioral simulation results are presented to demonstrate the effectiveness of the algorithm, in which all absolute values of comparator offsets are set to |3Vref/8|. SFDR, THD and SNR are improved, from 34.62-dB, 34.63-dB and 30.33-dB to 60.23-dB, 61.14-dB and 59.35-dB, respectively, for a 10-bit pipeline ADC.展开更多
Over the past several decades, there has been a significant surge in the development of Antibody-Drug Conjugates (ADCs). Designing an ideal ADC presents a multifaceted challenge, requiring the precise orchestration of...Over the past several decades, there has been a significant surge in the development of Antibody-Drug Conjugates (ADCs). Designing an ideal ADC presents a multifaceted challenge, requiring the precise orchestration of various elements such as antigens, antibodies, linkers, and payloads. While ADCs aim to target tumor cells specifically, several antigens can also be found in regular tissues, potentially compromising the specificity of ADCs in therapeutic applications. The complexity extends to antibody selection, necessitating effective targeting of the desired antigen and ensuring compatibility with linkers for effective payload delivery. Additionally, the linker and payload combination are critical for the ADC’s therapeutic efficiency, balancing stability in circulation and timely payload release upon target binding. ADC doses must be safe for normal tissues while ensuring the released payloads are effective. The success of ADCs is attributed to their unmatched efficacy compared to traditional chemotherapy agents. The current research article aims to provide a technical review of Antibody-Drug Conjugates (ADCs) for cancer therapies. A brief discussion on the basics of ADCs, regulatory approach, overview, and technical complexities for quantification is presented. This review also summarizes recently approved ADCs and introduces the concepts of antibodies, linkers, and payloads. The article also outlines cancer-specific ADCs currently in late-stage clinical trials for cancer treatment.展开更多
A new temperature compensation technique for ring-oscillator-based ADCs is proposed. This technique employs a novelcfixed-number-based algorithm and CTAT current biasing technology to compensate the temperature-depend...A new temperature compensation technique for ring-oscillator-based ADCs is proposed. This technique employs a novelcfixed-number-based algorithm and CTAT current biasing technology to compensate the temperature-dependent variations of the output, thus eliminating the need for digital calibrations. Simulation results prove that, with the proposed technique,the resolution in the temperature range of 0 to 100℃ can reach a 2mV quantization bin size with an input voltage span of 120mV at the sampling frequency of fs = 100kHz.展开更多
ADCS （automated data collection system） is the element of MDMS （meter data management system） and a module in charge of collecting the data from DCUs （data collection units） or meters in AMI （advanced metering ...ADCS （automated data collection system） is the element of MDMS （meter data management system） and a module in charge of collecting the data from DCUs （data collection units） or meters in AMI （advanced metering infrastructure）-based interactive two-way communications infrastructure. In this study, ADCS＇s functions for K-AMI （Korean Advanced Metering Infrastructure） were analyzed and the logical design of ADCS which is suitable for the requirements was suggested. A massive data collection and management functions was defined as very important functions of ADCS to meet optimal data processing mechanism. ADCS was designed for support about the fuctions of data collection and transfer, large capacity data processing, interactive services, parallel processing, etc.. Also, ADCS has roles of protocols exchange and gateway for service support in addition to data collection in AMI environment.展开更多
文摘本文研究了基于1-比特模数转换器(Analog to Digital Converters,ADCs)的大规模多输入多输出(Multiple Input Multiple Output,MIMO)系统上行链路的多用户频率同步问题,其中多个单天线用户与配置大规模天线阵列的基站采用正交频分复用(Orthogonal Frequency Division Multiplexing,OFDM)技术进行通信.针对多用户角度不重叠的场景,本文利用接收波束成形网络进行多用户干扰消除,从混叠的多用户信号中提取出目标用户的信息,进而对载波频偏(Carrier Frequency Offset,CFO)进行估计.其次,考虑1-比特ADC导致的量化噪声对系统性能的影响,理论推导了基站接收端处的信噪比(Signal-Noise Ratio,SNR).为了提升系统的性能,基于理论SNR对波束成形网络进行了优化设计.最后,计算机仿真结果显示了所提出的频偏估计算法与其他现有算法相比具有更好的性能.
文摘针对飞卫星姿态确定和控制系统(attitude determination and control system,ADCS)中,IGRF地磁场模型的计算复杂度高和存储空间量大的问题,设计了均匀采样和K曲率加权2种历表模型。首先,给出了均匀历表模型的软件流程、存储格式、轨道推演方法;然后,采用U曲率计算方法求解地磁场数据的离散曲率,并提出了K曲率加权方法设计非均匀历表模型;最后,比较了均匀采样和非均匀方法对原曲线的拟合程度,以及在ADCS中应用结果的比较。最终设计了适用于飞卫星的80点基于K曲率加权的非均匀历表模型,仅需0.96 kB存储空间,证明在计算速度和存储空间等方面和现有技术相比具有较大优势。
文摘This paper presents a fully-differential CMOS dynamic comparator for use in high-speed pipelined ADCs with low stage resolution. Because the architecture is based on the coupled current sources and differential input pairs, this comparator＇s threshold voltage can be adjusted to a desired level. Compared with traditional comparators, this one shows significant improvement in area,power,and speed. Fabricated in 0.35μm CMOS technology,it occupies only 30μm × 70μm. Simulation and measurement results indicate the comparator has a sampling frequency up to 1GHz with 2Vpp differential input signal range and only 181μW power consumption under a 3.3V supply. The speed/power ratio reaches up to 5524GS/J.
基金supported in part by the Key Research&Development Plan of Jiangsu Province(No.BE2018108)National Nature Science Foundation of China(Nos.61701198&61772243)+3 种基金Nature Science Foundation of Jiangsu Province(No.BK20170557)Nature Science Foundation for Higher Education Institutions of Jiangsu Province of China(No.17KJB510009)the open research fund of National Mobile Communications Research Laboratory,Southeast University(No.2018D13)Young Talent Project of Jiangsu University and Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.SJCX18_0742)
文摘In a millimeter-wave(mmWave)Massive multiple-input multiple-output(MIMO)systems,full-digital beamforming(i.e.,connecting each antenna with a specific radio-frequency(RF)chain)becomes inefficient due to the hardware cost and power consumption.Therefore,hybrid analog and digital transceiver where the number of RF chains are much smaller than that of the antennas has drawn great research interest.In this work,we investigate the use of low-resolution analog-to-digital converters(ADCs)in the uplink of multi-user hybrid and full-digital mmWave Massive MIMO systems.To be specific,we compare the performance of full-digital minimum mean square error(MMSE)and hybrid MMSE beamforming in both sum rates and energy efficiency.Accurate approximations of sum rates and energy efficiency are provided for both schemes,which captures the dominant factors.The analytical results show that full-digital beamforming outperforms hybrid beamforming in terms of sum rates and requires only a small portion(γ)of antennas used by hybrid beamforming to achieve the same sum rates.We given sufficient condition for full-digital beamforming to outperform hybrid beamforming in terms of energy efficiency.Moreover,an algorithm is proposed to search for the optimal ADC resolution bits.Numerical results demonstrate the correctness of the analysis.
文摘A reconfigurable intelligent surface(RIS)aided massive multiple-input multiple-output(MIMO)system is considered,where the base station employs a large antenna array with low-cost and low-power 1-bit analog-to-digital converters(ADCs).To compensate for the per-formance loss caused by the coarse quantization,oversampling is applied at the receiver.The main challenge for the acquisition of cascaded channel state information in such a system is to handle the distortion caused by the 1-bit quantization and the sample correlation caused by oversampling.In this work,Bussgang decomposition is applied to deal with the coarse quantization,and a Markov chain is developed to char-acterize the banded structure of the oversampling filter.An approximate message-passing based algorithm is proposed for the estimation of the cascaded channels.Simulation results demonstrate that our proposed 1-bit systems with oversampling can approach the 2-bit systems in terms of the mean square error performance while the former consumes much less power at the receiver.
文摘A domain extension algorithm to correct the comparator offsets of pipeline analog-to-digital converters (ADCs) is presented, in which the 1.5-bit/stage ADC quantify domain is extended from a three-domain to a five-domain. This algorithm is designed for high speed and low comparator accuracy application. The comparator offset correction ability is improved. This new approach also promises significant improvements to the spurious-free dynamic range (SFDR), the total harmonic distortion (THD), the signal-to-noise ratio (SNR) and the minor analog and digital circuit modifications. Behavioral simulation results are presented to demonstrate the effectiveness of the algorithm, in which all absolute values of comparator offsets are set to |3Vref/8|. SFDR, THD and SNR are improved, from 34.62-dB, 34.63-dB and 30.33-dB to 60.23-dB, 61.14-dB and 59.35-dB, respectively, for a 10-bit pipeline ADC.
文摘Over the past several decades, there has been a significant surge in the development of Antibody-Drug Conjugates (ADCs). Designing an ideal ADC presents a multifaceted challenge, requiring the precise orchestration of various elements such as antigens, antibodies, linkers, and payloads. While ADCs aim to target tumor cells specifically, several antigens can also be found in regular tissues, potentially compromising the specificity of ADCs in therapeutic applications. The complexity extends to antibody selection, necessitating effective targeting of the desired antigen and ensuring compatibility with linkers for effective payload delivery. Additionally, the linker and payload combination are critical for the ADC’s therapeutic efficiency, balancing stability in circulation and timely payload release upon target binding. ADC doses must be safe for normal tissues while ensuring the released payloads are effective. The success of ADCs is attributed to their unmatched efficacy compared to traditional chemotherapy agents. The current research article aims to provide a technical review of Antibody-Drug Conjugates (ADCs) for cancer therapies. A brief discussion on the basics of ADCs, regulatory approach, overview, and technical complexities for quantification is presented. This review also summarizes recently approved ADCs and introduces the concepts of antibodies, linkers, and payloads. The article also outlines cancer-specific ADCs currently in late-stage clinical trials for cancer treatment.
文摘A new temperature compensation technique for ring-oscillator-based ADCs is proposed. This technique employs a novelcfixed-number-based algorithm and CTAT current biasing technology to compensate the temperature-dependent variations of the output, thus eliminating the need for digital calibrations. Simulation results prove that, with the proposed technique,the resolution in the temperature range of 0 to 100℃ can reach a 2mV quantization bin size with an input voltage span of 120mV at the sampling frequency of fs = 100kHz.
文摘ADCS （automated data collection system） is the element of MDMS （meter data management system） and a module in charge of collecting the data from DCUs （data collection units） or meters in AMI （advanced metering infrastructure）-based interactive two-way communications infrastructure. In this study, ADCS＇s functions for K-AMI （Korean Advanced Metering Infrastructure） were analyzed and the logical design of ADCS which is suitable for the requirements was suggested. A massive data collection and management functions was defined as very important functions of ADCS to meet optimal data processing mechanism. ADCS was designed for support about the fuctions of data collection and transfer, large capacity data processing, interactive services, parallel processing, etc.. Also, ADCS has roles of protocols exchange and gateway for service support in addition to data collection in AMI environment.
