Code converters are essential in digital nano communication;therefore,a low-complexity optimal QCA layout for a BCD to Excess-3 code converter has been proposed in this paper.A QCA clockphase-based design technique wa...Code converters are essential in digital nano communication;therefore,a low-complexity optimal QCA layout for a BCD to Excess-3 code converter has been proposed in this paper.A QCA clockphase-based design technique was adopted to investigate integration with other complicated circuits.Using a unique XOR gate,the recommended circuit’s cell complexity has been decreased.The findings produced using the QCADesigner-2.0.3,a reliable simulation tool,prove the effectiveness of the current structure over earlier designs by considering the number of cells deployed,the area occupied,and the latency as design metrics.In addition,the popular tool QCAPro was used to estimate the energy dissipation of the proposed design.The proposed technique reduces the occupied space by∼40%,improves cell complexity by∼20%,and reduces energy dissipation by∼1.8 times(atγ=1.5EK)compared to the current scalable designs.This paper also studied the suggested structure’s energy dissipation and compared it to existing works for a better performance evaluation.展开更多
Kerr soliton microcombs have the potential to disrupt a variety of applications such as ultra-high-speed optical communications,ultra-fast distance measurements,massively parallel light detection and ranging(LiDAR)or ...Kerr soliton microcombs have the potential to disrupt a variety of applications such as ultra-high-speed optical communications,ultra-fast distance measurements,massively parallel light detection and ranging(LiDAR)or high-resolution optical spectroscopy.Similarly,ultra-broadband photonic-electronic signal processing could also benefit from chip-scale frequency comb sources that offer wideband optical emission along with ultra-low phase noise and timing jitter.However,while photonic analogue-to-digital converters(ADC)based on femtosecond lasers have been shown to overcome the jitter-related limitations of electronic oscillators,the potential of Kerr combs in photonic-electronic signal processing remains to be explored.In this work,we demonstrate a microcomb-based photonic-electronic ADC that combines a high-speed electro-optic modulator with a Kerr comb for spectrally sliced coherent detection of the generated optical waveform.The system offers a record-high acquisition bandwidth of 320 GHz,corresponding to an effective sampling rate of at least 640GSa/s.In a proof-of-concept experiment,we demonstrate the viability of the concept by acquiring a broadband analogue data signal comprising different channels with centre frequencies between 24 GHz and 264 GHz,offering bit error ratios(BER)below widely used forward-error-correction(FEC)thresholds.To the best of our knowledge,this is the first demonstration of a microcomb-based ADC,leading to the largest acquisition bandwidth demonstrated for any ADC so far.展开更多
Digital Communications, in relation to wireless networks, have taken off in recent years due to the expanding need to communicate faster and more efficiently. A popular way to achieve this is by using wireless Multipl...Digital Communications, in relation to wireless networks, have taken off in recent years due to the expanding need to communicate faster and more efficiently. A popular way to achieve this is by using wireless Multiple Input Multiple Output (MIMO) communication systems. MIMO systems utilize Space Time Block Codes (STBC) as one of the leading ways to obtain higher data rates with limited bandwidth and power. With several STBC methods currently available, this paper analyzes simulations using Orthogonal Space Time Block Codes (OSTBC) in Rayleigh fading channels to evaluate the performance of MIMO systems. The selection to use a Rayleigh fading channel as a model for a non-line-of-sight (nLOS) environment is selected to mimic installations where a large number of signal paths and reflections are expected. All simulations are coded, generated and plotted using MATLAB resulting in graphical data representing the bit-error rate (BER) to signal-to-noise ratio (Eb/N<sub>0</sub>) or SNR. Each simulation captures how different configurations of key variables including code rate, diversity and antenna count can impact system performance. Four modulation schemes (BPSK, QPSK, 16-QAM and 64-QAM) are included in each simulation. Conclusive evidence based upon these simulations suggests higher diversity gains were achieved with a greater number of antennas. The most significant factor for increasing system performance was using a lower count of transmit antennas with a higher count of receive antennas.展开更多
采用Xilinx公司的Kintex-7内部的进位链,实现了时间数字转换器(Time to Digital Converter,TDC)。采用码密度校准方法 对TDC进行逐位校准,标定了TDC的码宽。码密度校准过程中发现,不同的进位链抽头位置会导致TDC的码宽不同、非线性不同...采用Xilinx公司的Kintex-7内部的进位链,实现了时间数字转换器(Time to Digital Converter,TDC)。采用码密度校准方法 对TDC进行逐位校准,标定了TDC的码宽。码密度校准过程中发现,不同的进位链抽头位置会导致TDC的码宽不同、非线性不同,研究了2抽头、 4抽头方式下的TDC的码宽和非线性,在“0tap+3tap”的2抽头方式下,TDC可以获得较好的线性,时间分辨率为25 ps(对应最低有效位(Least Significant Bit,LSB)),微分非线性范围为-0.84~3.1 LSB,积分非线性范围为-5.2~2.2 LSB。展开更多
单光子探测在量子信息、生物医学、激光雷达成像等领域具有重要应用前景,InGaAs盖革雪崩焦平面具有单光子探测灵敏度,通过计量光子飞行时间实现距离探测,时间数字转换精度决定整个探测系统的测距精度,是近年来单光子探测领域的研究热点...单光子探测在量子信息、生物医学、激光雷达成像等领域具有重要应用前景,InGaAs盖革雪崩焦平面具有单光子探测灵敏度,通过计量光子飞行时间实现距离探测,时间数字转换精度决定整个探测系统的测距精度,是近年来单光子探测领域的研究热点。设计了一款64×64面阵型像素级高分辨低误码时间数字转换阵列电路(Time to Digital Converter,TDC),采用局部共享型高中低三段式异步周期TDC结构。低段位TDC全阵列共享,基于压控延迟链(Voltage Control Delay Line,VCDL)分相时钟实现亚纳秒计时;中高段位每个像素独享,中段位采用分频计数器降低时钟频率,降低阵列整体功耗,高段位采用线性反馈移位寄存器实扩展计时量程并实现计时、数据存储、输出一体化。采用延迟采样方案显著降低了因段间计数时钟不匹配导致的数据锁存误码问题。采用0.18μm CMOS工艺流片,实测250 MHz参考时钟频率下分辨率0.5 ns,积分非线性-0.4~0.6 LSB,微分非线性-0.4~0.4 LSB,TDC转换单调,有效量程位数13位,20 kHz帧频功耗380.5 mW。展开更多
文摘Code converters are essential in digital nano communication;therefore,a low-complexity optimal QCA layout for a BCD to Excess-3 code converter has been proposed in this paper.A QCA clockphase-based design technique was adopted to investigate integration with other complicated circuits.Using a unique XOR gate,the recommended circuit’s cell complexity has been decreased.The findings produced using the QCADesigner-2.0.3,a reliable simulation tool,prove the effectiveness of the current structure over earlier designs by considering the number of cells deployed,the area occupied,and the latency as design metrics.In addition,the popular tool QCAPro was used to estimate the energy dissipation of the proposed design.The proposed technique reduces the occupied space by∼40%,improves cell complexity by∼20%,and reduces energy dissipation by∼1.8 times(atγ=1.5EK)compared to the current scalable designs.This paper also studied the suggested structure’s energy dissipation and compared it to existing works for a better performance evaluation.
基金supported by the ERC Consolidator Grant TeraSHAPE(#773248)the H2020 project TeraSlice(#863322)+9 种基金by the EIC Transition projects MAGNIFY(#101113302),HDLN(#101113260),and CombTools(#101136978)by the H2020 Marie Skłodowska-Curie Innovative Training Network“MICROCOMB”(#812818)by the Deutsche Forschungsgemeinschaft(DFG)project PACE(#403188360)within the Priority Programme“Electronic-Photonic Integrated Systems for Ultrafast Signal Processing”(SPP 2111)by the DFG Collaborative Research Centre(CRC)WavePhenomena(SFB 1173,Project-ID 258734477)by the BMBF project Open6GHub(#16KISK010)by the Alfried Krupp von Bohlen und Halbach-Stiftung,and by the Max-Planck School of Photonics(MPSP)by the European Regional Development Fund(ERDF,grant EFRE/FEIH_776267)the Deutsche Forschungsgemeinschaft(DFGgrants DFG/INST 121384/166-1 and DFG/INST 121384/167-1The Si3N4 samples were fabricated in the Centre of MicroNano Technology(CMi)at EPFL.
文摘Kerr soliton microcombs have the potential to disrupt a variety of applications such as ultra-high-speed optical communications,ultra-fast distance measurements,massively parallel light detection and ranging(LiDAR)or high-resolution optical spectroscopy.Similarly,ultra-broadband photonic-electronic signal processing could also benefit from chip-scale frequency comb sources that offer wideband optical emission along with ultra-low phase noise and timing jitter.However,while photonic analogue-to-digital converters(ADC)based on femtosecond lasers have been shown to overcome the jitter-related limitations of electronic oscillators,the potential of Kerr combs in photonic-electronic signal processing remains to be explored.In this work,we demonstrate a microcomb-based photonic-electronic ADC that combines a high-speed electro-optic modulator with a Kerr comb for spectrally sliced coherent detection of the generated optical waveform.The system offers a record-high acquisition bandwidth of 320 GHz,corresponding to an effective sampling rate of at least 640GSa/s.In a proof-of-concept experiment,we demonstrate the viability of the concept by acquiring a broadband analogue data signal comprising different channels with centre frequencies between 24 GHz and 264 GHz,offering bit error ratios(BER)below widely used forward-error-correction(FEC)thresholds.To the best of our knowledge,this is the first demonstration of a microcomb-based ADC,leading to the largest acquisition bandwidth demonstrated for any ADC so far.
文摘Digital Communications, in relation to wireless networks, have taken off in recent years due to the expanding need to communicate faster and more efficiently. A popular way to achieve this is by using wireless Multiple Input Multiple Output (MIMO) communication systems. MIMO systems utilize Space Time Block Codes (STBC) as one of the leading ways to obtain higher data rates with limited bandwidth and power. With several STBC methods currently available, this paper analyzes simulations using Orthogonal Space Time Block Codes (OSTBC) in Rayleigh fading channels to evaluate the performance of MIMO systems. The selection to use a Rayleigh fading channel as a model for a non-line-of-sight (nLOS) environment is selected to mimic installations where a large number of signal paths and reflections are expected. All simulations are coded, generated and plotted using MATLAB resulting in graphical data representing the bit-error rate (BER) to signal-to-noise ratio (Eb/N<sub>0</sub>) or SNR. Each simulation captures how different configurations of key variables including code rate, diversity and antenna count can impact system performance. Four modulation schemes (BPSK, QPSK, 16-QAM and 64-QAM) are included in each simulation. Conclusive evidence based upon these simulations suggests higher diversity gains were achieved with a greater number of antennas. The most significant factor for increasing system performance was using a lower count of transmit antennas with a higher count of receive antennas.
文摘单光子探测在量子信息、生物医学、激光雷达成像等领域具有重要应用前景,InGaAs盖革雪崩焦平面具有单光子探测灵敏度,通过计量光子飞行时间实现距离探测,时间数字转换精度决定整个探测系统的测距精度,是近年来单光子探测领域的研究热点。设计了一款64×64面阵型像素级高分辨低误码时间数字转换阵列电路(Time to Digital Converter,TDC),采用局部共享型高中低三段式异步周期TDC结构。低段位TDC全阵列共享,基于压控延迟链(Voltage Control Delay Line,VCDL)分相时钟实现亚纳秒计时;中高段位每个像素独享,中段位采用分频计数器降低时钟频率,降低阵列整体功耗,高段位采用线性反馈移位寄存器实扩展计时量程并实现计时、数据存储、输出一体化。采用延迟采样方案显著降低了因段间计数时钟不匹配导致的数据锁存误码问题。采用0.18μm CMOS工艺流片,实测250 MHz参考时钟频率下分辨率0.5 ns,积分非线性-0.4~0.6 LSB,微分非线性-0.4~0.4 LSB,TDC转换单调,有效量程位数13位,20 kHz帧频功耗380.5 mW。
