The increasing use of color terminals for personal computers has raised a demand for video graphic adapter(VGA)-format panel displays. Since only monochrome(ZnS∶Mn) electroluminescence(EL) displays of suitable size a...The increasing use of color terminals for personal computers has raised a demand for video graphic adapter(VGA)-format panel displays. Since only monochrome(ZnS∶Mn) electroluminescence(EL) displays of suitable size and speed are available, lack of colors has to be replaced by grayscale in the first place. There are two basic driving methods to achieve grayscale in thin-film EL displays: pulse amplitude modulation(PAM) method and pulse width modulation(PWM) method. But there are serious disadvantages of the two traditional methods. For the former method, the high voltage PAM ICs are too expensive to produce the grayscale EL display in bulks and the driver integrated circuit(IC) is complex. Though the PWM method has good grayscale display quality, the hardware implementation is too complex. A new driving method with which the width and the amplitude of the pulse can be modulated and simultaneously the challenge can be solved efficaciously is presented.展开更多
LED调制带宽制约着可见光通信(VLC)系统的数据传输速率。为此,提出一种基于双重调制技术COB(chip on board)封装的LED灯具,通过实现16级脉冲振幅调制(PAM),将系统数据传输速率提升4倍;结合脉冲宽度调制(PWM)技术进行调光,同时兼顾室内...LED调制带宽制约着可见光通信(VLC)系统的数据传输速率。为此,提出一种基于双重调制技术COB(chip on board)封装的LED灯具,通过实现16级脉冲振幅调制(PAM),将系统数据传输速率提升4倍;结合脉冲宽度调制(PWM)技术进行调光,同时兼顾室内的照明及通信。采用Matlab软件模拟仿真视频传输试验。结果表明,在相同信噪比(SNR)的情况下,基于双重调制技术的VLC系统的误码率(BER)比传统使用开关键控(OOK)调控技术系统的BER更低。本文系统在不增加器件带宽前提下,成倍提高了无线通信的质量与数据传输速率;从照明与通信的角度优化了VLC系统的信源,具有广阔的应用前景。展开更多
文摘The increasing use of color terminals for personal computers has raised a demand for video graphic adapter(VGA)-format panel displays. Since only monochrome(ZnS∶Mn) electroluminescence(EL) displays of suitable size and speed are available, lack of colors has to be replaced by grayscale in the first place. There are two basic driving methods to achieve grayscale in thin-film EL displays: pulse amplitude modulation(PAM) method and pulse width modulation(PWM) method. But there are serious disadvantages of the two traditional methods. For the former method, the high voltage PAM ICs are too expensive to produce the grayscale EL display in bulks and the driver integrated circuit(IC) is complex. Though the PWM method has good grayscale display quality, the hardware implementation is too complex. A new driving method with which the width and the amplitude of the pulse can be modulated and simultaneously the challenge can be solved efficaciously is presented.
文摘LED调制带宽制约着可见光通信(VLC)系统的数据传输速率。为此,提出一种基于双重调制技术COB(chip on board)封装的LED灯具,通过实现16级脉冲振幅调制(PAM),将系统数据传输速率提升4倍;结合脉冲宽度调制(PWM)技术进行调光,同时兼顾室内的照明及通信。采用Matlab软件模拟仿真视频传输试验。结果表明,在相同信噪比(SNR)的情况下,基于双重调制技术的VLC系统的误码率(BER)比传统使用开关键控(OOK)调控技术系统的BER更低。本文系统在不增加器件带宽前提下,成倍提高了无线通信的质量与数据传输速率;从照明与通信的角度优化了VLC系统的信源,具有广阔的应用前景。
