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
Ultrawide bandwidth (UWB) radio, a very promising technique carrying information in very short basic pulses, has properties that make it a viable candidate for short-range wireless communications. In this paper, sever...Ultrawide bandwidth (UWB) radio, a very promising technique carrying information in very short basic pulses, has properties that make it a viable candidate for short-range wireless communications. In this paper, several short-pulse waveforms based on Gaussian genetic monocycle as well as Gaussian pulse waveform, as candidates of basic UWB pulse waveforms, are firstly proposed and investigated. Their spectrum characteristics, bit transmission rate (BTR), and bit error rate (BER) performance in AWGN channel using time hopping spread spectrum (THSS) and pulse position modulation (PPM) are simulated and evaluated. The numerical results are compared and show that the basic pulse waveforms determine the spectrum characteristics of UWB signals and have much effect on the performance of UWB radio system. The performance of UWB radio system achieved by the proposed basic pulse waveforms is much better than that of UWB radio system realized by other used basic pulse waveforms under the uniform conditions. Also, the polarity of these short basic pulses does not affect the performance of UWB radio system.展开更多
Recently, many studies propose the use of ultra-wideband technology for passive and active radio frequency identification systems as well as for wireless sensor networks due to its numerous advantages. By harvesting t...Recently, many studies propose the use of ultra-wideband technology for passive and active radio frequency identification systems as well as for wireless sensor networks due to its numerous advantages. By harvesting these advantages of IR-UWB technology at the physical-layer design, this paper proposes that a cross layer architecture platform can be considered as a good integrator for different wireless short-ranges indoor protocols into a universal smart wireless-tagged architecture with new promising applications in cognitive radio for future applications. Adaptive transmission algorithms have been studied to show the trade-off between different specific QoS requirements, transmission rates and distances at the physical layer level and this type of dynamic optimization and reconfiguration leads to the cross-layer design proposal in the paper. Studies from both theoretical simulation and statistical indoor environments experiments are considered as a proof of concept for the proposed architecture.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Ultrawide bandwidth (UWB) radio, a very promising technique carrying information in very short basic pulses, has properties that make it a viable candidate for short-range wireless communications. In this paper, several short-pulse waveforms based on Gaussian genetic monocycle as well as Gaussian pulse waveform, as candidates of basic UWB pulse waveforms, are firstly proposed and investigated. Their spectrum characteristics, bit transmission rate (BTR), and bit error rate (BER) performance in AWGN channel using time hopping spread spectrum (THSS) and pulse position modulation (PPM) are simulated and evaluated. The numerical results are compared and show that the basic pulse waveforms determine the spectrum characteristics of UWB signals and have much effect on the performance of UWB radio system. The performance of UWB radio system achieved by the proposed basic pulse waveforms is much better than that of UWB radio system realized by other used basic pulse waveforms under the uniform conditions. Also, the polarity of these short basic pulses does not affect the performance of UWB radio system.
文摘Recently, many studies propose the use of ultra-wideband technology for passive and active radio frequency identification systems as well as for wireless sensor networks due to its numerous advantages. By harvesting these advantages of IR-UWB technology at the physical-layer design, this paper proposes that a cross layer architecture platform can be considered as a good integrator for different wireless short-ranges indoor protocols into a universal smart wireless-tagged architecture with new promising applications in cognitive radio for future applications. Adaptive transmission algorithms have been studied to show the trade-off between different specific QoS requirements, transmission rates and distances at the physical layer level and this type of dynamic optimization and reconfiguration leads to the cross-layer design proposal in the paper. Studies from both theoretical simulation and statistical indoor environments experiments are considered as a proof of concept for the proposed architecture.
文摘采用基于软判决和硬判决的方法,对跳时脉冲位置调制(time hopping-pulse position modulation,TH-PPM)和跳时脉冲幅度调制(time hopping-pulse amplitude modulation,TH-PAM)超宽带系统的误比特率性能进行了分析和比较.在加性高斯白噪声(additive white Gausses noise,AWGN)信道下,研究了TH-PPM和TH-PAM超宽带单用户系统接收端信号进行软判决和硬判决时的性能,同时分析比较系统在两种调制方式下采用不同脉冲重复次数时的性能差异.仿真结果表明,在AWGN信道下,TH-PPM和TH-PAM的系统性能均随脉冲重复次数的增加而明显改善,并且后者优于前者.此外,采用软判决时的系统性能优于采用硬判决时的系统性能.
