为了降低光纤长距离传输中电域色散补偿(EDC,Electronic Dispersion Compensation)的实现复杂度,采用正交频分复用技术(OFDM,Orthogonal Frequency Division Multiplexing)与光单边带调制(OSSB,Optical Single Sideband),可有效实现光...为了降低光纤长距离传输中电域色散补偿(EDC,Electronic Dispersion Compensation)的实现复杂度,采用正交频分复用技术(OFDM,Orthogonal Frequency Division Multiplexing)与光单边带调制(OSSB,Optical Single Sideband),可有效实现光纤的色散补偿。文章介绍了基于光直接检测(DD,Direct-Detection)的OFDM系统,重点对系统色散补偿的实现进行了具体的数学分析,并进行了数字仿真,就系统误码率(BER)与传统光传输系统(NRZ,Non-Return-to-Zero)进行了比较。结果表明,较传统光传输中电域色散补偿,基于光直接检测的OFDM系统色散补偿实现简单,系统复杂度降低,同时也提高了系统性能。展开更多
Modulation techniques for light fidelity （Li-Fi） are reviewed in this paper. Li-Fi is the fully networked solution for nmltiple users that combines communication and illumination simultaneously. Light emitting diod...Modulation techniques for light fidelity （Li-Fi） are reviewed in this paper. Li-Fi is the fully networked solution for nmltiple users that combines communication and illumination simultaneously. Light emitting diodes （LEDs） are used in Li-Fi as visible light transmitters, therefore, only intensity modulated direct detected modulation techniques can be achieved. Single carrier modulation techniques are straightforward to be used in Li-Fi, however, computationally complex equalization processes are required in fre- quency selective Li-Fi channels. On the other hand, multiearrier modulation techniques offer a viable solution for Li-Fi in terms of power, spectral and computational efficiency. In particular, orthogonal frequency division multiplexing （OFDM） based modulation techniques offer a practical solution for Li-Fi, especially when direct current （DC） wander, and adaptive bit and power loading techniques are considered. Li-Fi modulation techniques need to also satisfy illumination requirements. Flickering avoidance and dimming control are considered in the variant modulation techniques presented. This paper surveys the suitable modulation techniques for Li-Fi including those which explore time, frequency and colour domains.展开更多
文摘为了降低光纤长距离传输中电域色散补偿(EDC,Electronic Dispersion Compensation)的实现复杂度,采用正交频分复用技术(OFDM,Orthogonal Frequency Division Multiplexing)与光单边带调制(OSSB,Optical Single Sideband),可有效实现光纤的色散补偿。文章介绍了基于光直接检测(DD,Direct-Detection)的OFDM系统,重点对系统色散补偿的实现进行了具体的数学分析,并进行了数字仿真,就系统误码率(BER)与传统光传输系统(NRZ,Non-Return-to-Zero)进行了比较。结果表明,较传统光传输中电域色散补偿,基于光直接检测的OFDM系统色散补偿实现简单,系统复杂度降低,同时也提高了系统性能。
基金support by the UK Engineering and Physical Sciences Research Council(EPSRC)under Grants EP/K008757/1 and EP/M506515/1
文摘Modulation techniques for light fidelity （Li-Fi） are reviewed in this paper. Li-Fi is the fully networked solution for nmltiple users that combines communication and illumination simultaneously. Light emitting diodes （LEDs） are used in Li-Fi as visible light transmitters, therefore, only intensity modulated direct detected modulation techniques can be achieved. Single carrier modulation techniques are straightforward to be used in Li-Fi, however, computationally complex equalization processes are required in fre- quency selective Li-Fi channels. On the other hand, multiearrier modulation techniques offer a viable solution for Li-Fi in terms of power, spectral and computational efficiency. In particular, orthogonal frequency division multiplexing （OFDM） based modulation techniques offer a practical solution for Li-Fi, especially when direct current （DC） wander, and adaptive bit and power loading techniques are considered. Li-Fi modulation techniques need to also satisfy illumination requirements. Flickering avoidance and dimming control are considered in the variant modulation techniques presented. This paper surveys the suitable modulation techniques for Li-Fi including those which explore time, frequency and colour domains.
