A novel concept of collision avoidance single-photon light detection and ranging（LIDAR） for vehicles has been demonstrated, in which chaotic pulse position modulation is applied on the transmitted laser pulses for r...A novel concept of collision avoidance single-photon light detection and ranging（LIDAR） for vehicles has been demonstrated, in which chaotic pulse position modulation is applied on the transmitted laser pulses for robust anti-crosstalk purposes. Besides, single-photon detectors（SPD） and time correlated single photon counting techniques are adapted, to sense the ultra-low power used for the consideration of compact structure and eye safety. Parameters including pulse rate, discrimination threshold, and number of accumulated pulses have been thoroughly analyzed based on the detection requirements, resulting in specified receiver operating characteristics curves. Both simulation and indoor experiments were performed to verify the excellent anti-crosstalk capability of the presented collision avoidance LIDAR despite ultra-low transmitting power.展开更多
针对小型水下无人平台等水下设备对近距、高速率、低复杂度水下数据交互需求,设计一种高速率低复杂度水声通信方案。该方案采用PPM(Pulse Position Modulation)调制方式以直接硬件生成四相位时钟同步采样的方式实现低复杂度解调,从而降...针对小型水下无人平台等水下设备对近距、高速率、低复杂度水下数据交互需求,设计一种高速率低复杂度水声通信方案。该方案采用PPM(Pulse Position Modulation)调制方式以直接硬件生成四相位时钟同步采样的方式实现低复杂度解调,从而降低对硬件算力的要求;同时,利用PPM调制中脉冲间隔形成的特点和脉冲信号的快速衰减特性抑制高频水声信道多径干扰,避免采用高复杂度的信道均衡处理。实验室水池实验表明了采用该方案的通信样机在米级距离达到Mbps级传输速率的有效性。展开更多
为了保证可见光通信(VLC)系统能够为智能终端提供高速率、低能耗的数据传输服务。该文基于脉冲位置调制(PPM)技术,提出了一种新型的无载波位相(CPP)调制技术,即通过运用正交滤波器提高了PPM的传输速率。而针对采用CPP调制在VLC系统中功...为了保证可见光通信(VLC)系统能够为智能终端提供高速率、低能耗的数据传输服务。该文基于脉冲位置调制(PPM)技术,提出了一种新型的无载波位相(CPP)调制技术,即通过运用正交滤波器提高了PPM的传输速率。而针对采用CPP调制在VLC系统中功率效率显著降低的问题,提出了全新的时变偏置有效地降低了系统的功耗。最后仿真结果表明,采用时变偏置的CPP系统同采用直流偏置相比,在获得相同BER性能且带宽受限的情况下可以节省2 d B的信噪比。而同时考虑信号时隙之间的相关性,时变偏置可以进一步提升约1.5 d B的BER性能。展开更多
基金Project supported by Tsinghua University Initiative Scientific Research Program,China(Grant No.2014z21035)
文摘A novel concept of collision avoidance single-photon light detection and ranging（LIDAR） for vehicles has been demonstrated, in which chaotic pulse position modulation is applied on the transmitted laser pulses for robust anti-crosstalk purposes. Besides, single-photon detectors（SPD） and time correlated single photon counting techniques are adapted, to sense the ultra-low power used for the consideration of compact structure and eye safety. Parameters including pulse rate, discrimination threshold, and number of accumulated pulses have been thoroughly analyzed based on the detection requirements, resulting in specified receiver operating characteristics curves. Both simulation and indoor experiments were performed to verify the excellent anti-crosstalk capability of the presented collision avoidance LIDAR despite ultra-low transmitting power.
文摘针对小型水下无人平台等水下设备对近距、高速率、低复杂度水下数据交互需求,设计一种高速率低复杂度水声通信方案。该方案采用PPM(Pulse Position Modulation)调制方式以直接硬件生成四相位时钟同步采样的方式实现低复杂度解调,从而降低对硬件算力的要求;同时,利用PPM调制中脉冲间隔形成的特点和脉冲信号的快速衰减特性抑制高频水声信道多径干扰,避免采用高复杂度的信道均衡处理。实验室水池实验表明了采用该方案的通信样机在米级距离达到Mbps级传输速率的有效性。
文摘为了保证可见光通信(VLC)系统能够为智能终端提供高速率、低能耗的数据传输服务。该文基于脉冲位置调制(PPM)技术,提出了一种新型的无载波位相(CPP)调制技术,即通过运用正交滤波器提高了PPM的传输速率。而针对采用CPP调制在VLC系统中功率效率显著降低的问题,提出了全新的时变偏置有效地降低了系统的功耗。最后仿真结果表明,采用时变偏置的CPP系统同采用直流偏置相比,在获得相同BER性能且带宽受限的情况下可以节省2 d B的信噪比。而同时考虑信号时隙之间的相关性,时变偏置可以进一步提升约1.5 d B的BER性能。
