We experimentally demonstrate a 750 Mb/s real-time visible light communication（VLC） system based on non-return-to-zero on–off keying modulation by employing single commercially available monochromatic lightemitting...We experimentally demonstrate a 750 Mb/s real-time visible light communication（VLC） system based on non-return-to-zero on–off keying modulation by employing single commercially available monochromatic lightemitting diodes. To enhance the 3-d B bandwidth of the VLC link, we propose a low-complexity cascaded post-equalizer based on NPN transistors. With two different frequency-selecting networks in our post-equalizer,the highest achieved 3-d B bandwidth of the VLC link is 370 MHz. The highest achieved data rate is 750 Mb/s at a communication distance of 170 cm with a bit error rate below 1 × 10^（-6）, which is far below the forward error correction limit（3.8 × 10^（-3））. Based on our monochromatic VLC system, a wavelength-division multiplexing VLC system could be designed with a higher data rate.展开更多
A sliding mode control design for a miniature unmanned helicopter is presented. The control objective is to let the helicopter track some predefined velocity and yaw trajectories. A new sliding mode control design met...A sliding mode control design for a miniature unmanned helicopter is presented. The control objective is to let the helicopter track some predefined velocity and yaw trajectories. A new sliding mode control design method is developed based on a linearized dynamic model. In order to facilitate the control design, the helicopter＇s dynamic model is divided into two subsystems,such as the longitudinal-lateral and the heading-heave subsystem. The proposed controller employs sliding mode control technique to compensate for the immeasurable flapping angles＇ dynamic effects and external disturbances. The global asymptotic stability（GAS） of the closed-loop system is proved by the Lyapunov based stability analysis. Numerical simulations demonstrate that the proposed controller can achieve superior tracking performance compared with the proportionalintegral-derivative（PID） and linear-quadratic regulator（LQR） cascaded controller in the presence of wind gust disturbances.展开更多
Compact transmitter and receiver optical sub-assemblies（TOSA and ROSA） are fabricated in our laboratory and have an aggregated capacity of 100 Gb/s. Specially, directly modulated laser（DML） drivers with two layers...Compact transmitter and receiver optical sub-assemblies（TOSA and ROSA） are fabricated in our laboratory and have an aggregated capacity of 100 Gb/s. Specially, directly modulated laser（DML） drivers with two layers of electrical circuit boards are designed to inject RF signals and bias currents separately. For all the lanes, the3 dB bandwidth of the cascade of the TOSA and ROSA exceeds 9 GHz, which allows the 12.5 Gb/s operation.With the 12.5 Gb/s × 8-lane operation, clear eye diagrams for back-to-back and 30-km amplified transmission with a dispersion compensation fiber are achieved. Low cost and simple processing technology make it possible to realize commercial production.展开更多
基金supported by the National 973 Project of China(No.2013CB329202)the National Natural Science Foundation of China(No.61571067)
文摘We experimentally demonstrate a 750 Mb/s real-time visible light communication（VLC） system based on non-return-to-zero on–off keying modulation by employing single commercially available monochromatic lightemitting diodes. To enhance the 3-d B bandwidth of the VLC link, we propose a low-complexity cascaded post-equalizer based on NPN transistors. With two different frequency-selecting networks in our post-equalizer,the highest achieved 3-d B bandwidth of the VLC link is 370 MHz. The highest achieved data rate is 750 Mb/s at a communication distance of 170 cm with a bit error rate below 1 × 10^（-6）, which is far below the forward error correction limit（3.8 × 10^（-3））. Based on our monochromatic VLC system, a wavelength-division multiplexing VLC system could be designed with a higher data rate.
基金supported by the Natural Science Foundation of Tianjin(No.14JCZDJC31900)
文摘A sliding mode control design for a miniature unmanned helicopter is presented. The control objective is to let the helicopter track some predefined velocity and yaw trajectories. A new sliding mode control design method is developed based on a linearized dynamic model. In order to facilitate the control design, the helicopter＇s dynamic model is divided into two subsystems,such as the longitudinal-lateral and the heading-heave subsystem. The proposed controller employs sliding mode control technique to compensate for the immeasurable flapping angles＇ dynamic effects and external disturbances. The global asymptotic stability（GAS） of the closed-loop system is proved by the Lyapunov based stability analysis. Numerical simulations demonstrate that the proposed controller can achieve superior tracking performance compared with the proportionalintegral-derivative（PID） and linear-quadratic regulator（LQR） cascaded controller in the presence of wind gust disturbances.
基金supported by the National High-Tech Research and Development Program of China(No.2013AA014201)the National Natural Science Foundation of China(Nos.61575186 and 61635001)
文摘Compact transmitter and receiver optical sub-assemblies（TOSA and ROSA） are fabricated in our laboratory and have an aggregated capacity of 100 Gb/s. Specially, directly modulated laser（DML） drivers with two layers of electrical circuit boards are designed to inject RF signals and bias currents separately. For all the lanes, the3 dB bandwidth of the cascade of the TOSA and ROSA exceeds 9 GHz, which allows the 12.5 Gb/s operation.With the 12.5 Gb/s × 8-lane operation, clear eye diagrams for back-to-back and 30-km amplified transmission with a dispersion compensation fiber are achieved. Low cost and simple processing technology make it possible to realize commercial production.
