The Experts below are selected from a list of 26475 Experts worldwide ranked by ideXlab platform

Yiguang Wang - One of the best experts on this subject based on the ideXlab platform.

  • enhanced performance of a high speed wdm cap64 vlc system employing volterra series based nonlinear equalizer
    IEEE Photonics Journal, 2015
    Co-Authors: Yiguang Wang, Xingxing Huang, Li Tao, Jianyang Shi, Nan Chi
    Abstract:

    The light-emitting diode nonlinearity in visible light communication (VLC) systems is considered to be a major problem that deterioRates system performance. In this paper, we experimentally demonstRate a high-speed WDM CAP64 VLC system employing a Volterra series-based nonlinear equalizer to mitigate the nonlinear effect. A modified cascaded multimodulus algorithm (M-CMMA) is utilized to calculate the error function and update the weights of the nonlinear equalizer without using training symbols. An Aggregate Data Rate of 4.5 Gb/s is successfully achieved over 2-m indoor free-space transmission with a bit error Rate (BER) below the 7% forward error correction limit of 3.8 × 10 -3 . With the Volterra nonlinear equalizer, the Q factor of the VLC system is 1. 6 dB better than that without using the nonlinear equalizer, and the transmission distance is also increased by about 110 cm at the BER of 3.8 × 10 -3 . To the best of our knowledge, this is the first time that the Volterra nonlinear equalizer is utilized for high-speed carrierless amplitude and phase (CAP) modulation-based VLC systems.

  • 4 5 gb s rgb led based wdm visible light communication system employing cap modulation and rls based adaptive equalization
    Optics Express, 2015
    Co-Authors: Yiguang Wang, Xingxing Huang, Li Tao, Jianyang Shi, Nan Chi
    Abstract:

    Inter-symbol interference (ISI) is one of the key problems that seriously limit transmission Data Rate in high-speed VLC systems. To eliminate ISI and further improve the system performance, series of equalization schemes have been widely investigated. As an adaptive algorithm commonly used in wireless communication, RLS is also suitable for visible light communication due to its quick convergence and better performance. In this paper, for the first time we experimentally demonstRate a high-speed RGB-LED based WDM VLC system employing carrier-less amplitude and phase (CAP) modulation and recursive least square (RLS) based adaptive equalization. An Aggregate Data Rate of 4.5Gb/s is successfully achieved over 1.5-m indoor free space transmission with the bit error Rate (BER) below the 7% forward error correction (FEC) limit of 3.8x10−3. To the best of our knowledge, this is the highest Data Rate ever achieved in RGB-LED based VLC systems.

  • 8-Gb/s RGBY LED-Based WDM VLC System Employing High-Order CAP Modulation and Hybrid Post Equalizer
    IEEE Photonics Journal, 2015
    Co-Authors: Yiguang Wang, Xingxing Huang
    Abstract:

    In this paper, for the first time, we propose the use of a hybrid post equalizer in a high-order carrierless-amplitude-and-phase-modulation-based visible light communication (VLC) system. The hybrid equalizer consists of a linear equalizer, a Volterra-series-based nonlinear equalizer, and a decision-directed least mean squares equalizer to simultaneously mitigate the linear and nonlinear distortions of the VLC system. A commercially available red-blue-green-yellow light-emitting diode (RBGY LED) is utilized for four-wavelength multiplexing. By the hybrid equalizer, an Aggregate Data Rate of 8 Gb/s is experimentally achieved over a 1-m indoor free-space transmission with the bit error Rate (BER) below the 7% forward error correction (FEC) limit of 3.8 × 10-3. To the best of our knowledge, this is the highest Data Rate ever reported in high-speed VLC systems.

  • Enhanced performance of visible light communication employing 512-QAM N-SC-FDE and DD-LMS
    Optics Express, 2014
    Co-Authors: Yuanquan Wang, Junwen Zhang, Xingxing Huang, Yiguang Wang
    Abstract:

    In this paper, a novel hybrid time-frequency adaptive equalization algorithm based on a combination of frequency domain equalization (FDE) and decision-directed least mean square (DD-LMS) is proposed and experimentally demonstRated in a Nyquist single carrier visible light communication (VLC) system. Adopting this scheme, as well with 512-ary quadrature amplitude modulation (512-QAM) and wavelength multiplexing division (WDM), an Aggregate Data Rate of 4.22-Gb/s is successfully achieved employing a single commercially available red-green-blue (RGB) light emitting diode (LED) with low bandwidth. The measured Q-factors for 3 wavelength channels are all above the Q-limit. To the best of our knowledge, this is the highest Data Rate ever achieved by employing a commercially available RGB-LED.

  • gigabit polarization division multiplexing in visible light communication
    Optics Letters, 2014
    Co-Authors: Yuanquan Wang, Yiguang Wang, Chao Yang, Nan Chi
    Abstract:

    In this Letter, polarization division multiplexing is proposed and experimentally demonstRated for the first time that we know of, in visible light communication systems based on incoherent light emitting diodes and two orthogonal groups of linear polarizers. Spectrally efficient 16-ary quadrature amplitude modulation Nyquist single carrier frequency domain equalization is employed to obtain a maximum spectral efficiency. We achieve an Aggregate Data Rate of 1  Gb/s, with bit error Rate results for two polarization directions both below the 7% pre-forward-error-correction threshold of 3.8×10−3 after 80 cm free-space transmission. Moreover, the cross talk between x and y polarization is also discussed and analyzed.

Nan Chi - One of the best experts on this subject based on the ideXlab platform.

  • enhanced performance of a high speed wdm cap64 vlc system employing volterra series based nonlinear equalizer
    IEEE Photonics Journal, 2015
    Co-Authors: Yiguang Wang, Xingxing Huang, Li Tao, Jianyang Shi, Nan Chi
    Abstract:

    The light-emitting diode nonlinearity in visible light communication (VLC) systems is considered to be a major problem that deterioRates system performance. In this paper, we experimentally demonstRate a high-speed WDM CAP64 VLC system employing a Volterra series-based nonlinear equalizer to mitigate the nonlinear effect. A modified cascaded multimodulus algorithm (M-CMMA) is utilized to calculate the error function and update the weights of the nonlinear equalizer without using training symbols. An Aggregate Data Rate of 4.5 Gb/s is successfully achieved over 2-m indoor free-space transmission with a bit error Rate (BER) below the 7% forward error correction limit of 3.8 × 10 -3 . With the Volterra nonlinear equalizer, the Q factor of the VLC system is 1. 6 dB better than that without using the nonlinear equalizer, and the transmission distance is also increased by about 110 cm at the BER of 3.8 × 10 -3 . To the best of our knowledge, this is the first time that the Volterra nonlinear equalizer is utilized for high-speed carrierless amplitude and phase (CAP) modulation-based VLC systems.

  • 4 5 gb s rgb led based wdm visible light communication system employing cap modulation and rls based adaptive equalization
    Optics Express, 2015
    Co-Authors: Yiguang Wang, Xingxing Huang, Li Tao, Jianyang Shi, Nan Chi
    Abstract:

    Inter-symbol interference (ISI) is one of the key problems that seriously limit transmission Data Rate in high-speed VLC systems. To eliminate ISI and further improve the system performance, series of equalization schemes have been widely investigated. As an adaptive algorithm commonly used in wireless communication, RLS is also suitable for visible light communication due to its quick convergence and better performance. In this paper, for the first time we experimentally demonstRate a high-speed RGB-LED based WDM VLC system employing carrier-less amplitude and phase (CAP) modulation and recursive least square (RLS) based adaptive equalization. An Aggregate Data Rate of 4.5Gb/s is successfully achieved over 1.5-m indoor free space transmission with the bit error Rate (BER) below the 7% forward error correction (FEC) limit of 3.8x10−3. To the best of our knowledge, this is the highest Data Rate ever achieved in RGB-LED based VLC systems.

  • gigabit polarization division multiplexing in visible light communication
    Optics Letters, 2014
    Co-Authors: Yuanquan Wang, Yiguang Wang, Chao Yang, Nan Chi
    Abstract:

    In this Letter, polarization division multiplexing is proposed and experimentally demonstRated for the first time that we know of, in visible light communication systems based on incoherent light emitting diodes and two orthogonal groups of linear polarizers. Spectrally efficient 16-ary quadrature amplitude modulation Nyquist single carrier frequency domain equalization is employed to obtain a maximum spectral efficiency. We achieve an Aggregate Data Rate of 1  Gb/s, with bit error Rate results for two polarization directions both below the 7% pre-forward-error-correction threshold of 3.8×10−3 after 80 cm free-space transmission. Moreover, the cross talk between x and y polarization is also discussed and analyzed.

Ivan B Djordjevic - One of the best experts on this subject based on the ideXlab platform.

  • 500 gb s free space optical transmission over strong atmospheric turbulence channels
    Optics Letters, 2016
    Co-Authors: Ivan B Djordjevic
    Abstract:

    We experimentally demonstRate a high-spectral-efficiency, large-capacity, featured free-space-optical (FSO) transmission system by using low-density, parity-check (LDPC) coded quadrature phase shift keying (QPSK) combined with orbital angular momentum (OAM) multiplexing. The strong atmospheric turbulence channel is emulated by two spatial light modulators on which four randomly geneRated azimuthal phase patterns yielding the Andrews spectrum are recorded. The validity of such an approach is verified by reproducing the intensity distribution and irradiance correlation function (ICF) from the full-scale simulator. Excellent agreement of experimental, numerical, and analytical results is found. To reduce the phase distortion induced by the turbulence emulator, the inexpensive wavefront sensorless adaptive optics (AO) is used. To deal with remaining channel impairments, a large-girth LDPC code is used. To further improve the Aggregate Data Rate, the OAM multiplexing is combined with WDM, and 500 Gb/s optical transmission over the strong atmospheric turbulence channels is demonstRated.

  • 500 gb s free space optical transmission over strong atmospheric turbulence channels
    Optics Letters, 2016
    Co-Authors: Zhen Qu, Ivan B Djordjevic
    Abstract:

    We experimentally demonstRate a high-spectral-efficiency, large-capacity, featured free-space-optical (FSO) transmission system by using low-density, parity-check (LDPC) coded quadrature phase shift keying (QPSK) combined with orbital angular momentum (OAM) multiplexing. The strong atmospheric turbulence channel is emulated by two spatial light modulators on which four randomly geneRated azimuthal phase patterns yielding the Andrews spectrum are recorded. The validity of such an approach is verified by reproducing the intensity distribution and irradiance correlation function (ICF) from the full-scale simulator. Excellent agreement of experimental, numerical, and analytical results is found. To reduce the phase distortion induced by the turbulence emulator, the inexpensive wavefront sensorless adaptive optics (AO) is used. To deal with remaining channel impairments, a large-girth LDPC code is used. To further improve the Aggregate Data Rate, the OAM multiplexing is combined with WDM, and 500 Gb/s optical transmission over the strong atmospheric turbulence channels is demonstRated.

  • heterogeneous transparent optical networking based on coded oam modulation
    IEEE Photonics Journal, 2011
    Co-Authors: Ivan B Djordjevic
    Abstract:

    In this paper, we propose a coded orbital angular momentum (OAM)-based heterogeneous transparent optical networking scenario. The OAM is associated with the azimuthal phase dependence of the complex electric field. Because OAM eigenstates are orthogonal, they can be used as basis functions for multidimensional signal constellations. From Shannon's theory, we know that information capacity is a linear function of a number of dimensions and a logarithmic function of signal-to-noise ratio (SNR). Therefore, through multidimensional signal constellations, we can dramatically improve the overall Aggregate Data Rate per single wavelength. The ability to geneRate the OAM modes, such as Bessel and Laguerre-Gaussian (LG) modes, in both multimode fibers (MMFs) and free-space optical (FSO) links will allow the realization of heterogeneous transparent FSO-fiber-optics communication networks, composed of MMF and FSO links, with ultrahigh bits-per-photon efficiencies. We perform Monte Carlo simulations to demonstRate the feasibility of the proposed heterogeneous optical networking scenario. We demonstRate the high potential of the proposed network to solve high-bandwidth demands and interoperability problems simultaneously. Finally, we prove that a dramatic improvement in spectral efficiency is possible by employing this OAM-based multidimensional signaling scheme.

Xingxing Huang - One of the best experts on this subject based on the ideXlab platform.

  • enhanced performance of a high speed wdm cap64 vlc system employing volterra series based nonlinear equalizer
    IEEE Photonics Journal, 2015
    Co-Authors: Yiguang Wang, Xingxing Huang, Li Tao, Jianyang Shi, Nan Chi
    Abstract:

    The light-emitting diode nonlinearity in visible light communication (VLC) systems is considered to be a major problem that deterioRates system performance. In this paper, we experimentally demonstRate a high-speed WDM CAP64 VLC system employing a Volterra series-based nonlinear equalizer to mitigate the nonlinear effect. A modified cascaded multimodulus algorithm (M-CMMA) is utilized to calculate the error function and update the weights of the nonlinear equalizer without using training symbols. An Aggregate Data Rate of 4.5 Gb/s is successfully achieved over 2-m indoor free-space transmission with a bit error Rate (BER) below the 7% forward error correction limit of 3.8 × 10 -3 . With the Volterra nonlinear equalizer, the Q factor of the VLC system is 1. 6 dB better than that without using the nonlinear equalizer, and the transmission distance is also increased by about 110 cm at the BER of 3.8 × 10 -3 . To the best of our knowledge, this is the first time that the Volterra nonlinear equalizer is utilized for high-speed carrierless amplitude and phase (CAP) modulation-based VLC systems.

  • 4 5 gb s rgb led based wdm visible light communication system employing cap modulation and rls based adaptive equalization
    Optics Express, 2015
    Co-Authors: Yiguang Wang, Xingxing Huang, Li Tao, Jianyang Shi, Nan Chi
    Abstract:

    Inter-symbol interference (ISI) is one of the key problems that seriously limit transmission Data Rate in high-speed VLC systems. To eliminate ISI and further improve the system performance, series of equalization schemes have been widely investigated. As an adaptive algorithm commonly used in wireless communication, RLS is also suitable for visible light communication due to its quick convergence and better performance. In this paper, for the first time we experimentally demonstRate a high-speed RGB-LED based WDM VLC system employing carrier-less amplitude and phase (CAP) modulation and recursive least square (RLS) based adaptive equalization. An Aggregate Data Rate of 4.5Gb/s is successfully achieved over 1.5-m indoor free space transmission with the bit error Rate (BER) below the 7% forward error correction (FEC) limit of 3.8x10−3. To the best of our knowledge, this is the highest Data Rate ever achieved in RGB-LED based VLC systems.

  • 8-Gb/s RGBY LED-Based WDM VLC System Employing High-Order CAP Modulation and Hybrid Post Equalizer
    IEEE Photonics Journal, 2015
    Co-Authors: Yiguang Wang, Xingxing Huang
    Abstract:

    In this paper, for the first time, we propose the use of a hybrid post equalizer in a high-order carrierless-amplitude-and-phase-modulation-based visible light communication (VLC) system. The hybrid equalizer consists of a linear equalizer, a Volterra-series-based nonlinear equalizer, and a decision-directed least mean squares equalizer to simultaneously mitigate the linear and nonlinear distortions of the VLC system. A commercially available red-blue-green-yellow light-emitting diode (RBGY LED) is utilized for four-wavelength multiplexing. By the hybrid equalizer, an Aggregate Data Rate of 8 Gb/s is experimentally achieved over a 1-m indoor free-space transmission with the bit error Rate (BER) below the 7% forward error correction (FEC) limit of 3.8 × 10-3. To the best of our knowledge, this is the highest Data Rate ever reported in high-speed VLC systems.

  • Enhanced performance of visible light communication employing 512-QAM N-SC-FDE and DD-LMS
    Optics Express, 2014
    Co-Authors: Yuanquan Wang, Junwen Zhang, Xingxing Huang, Yiguang Wang
    Abstract:

    In this paper, a novel hybrid time-frequency adaptive equalization algorithm based on a combination of frequency domain equalization (FDE) and decision-directed least mean square (DD-LMS) is proposed and experimentally demonstRated in a Nyquist single carrier visible light communication (VLC) system. Adopting this scheme, as well with 512-ary quadrature amplitude modulation (512-QAM) and wavelength multiplexing division (WDM), an Aggregate Data Rate of 4.22-Gb/s is successfully achieved employing a single commercially available red-green-blue (RGB) light emitting diode (LED) with low bandwidth. The measured Q-factors for 3 wavelength channels are all above the Q-limit. To the best of our knowledge, this is the highest Data Rate ever achieved by employing a commercially available RGB-LED.

Yuanquan Wang - One of the best experts on this subject based on the ideXlab platform.

  • Enhanced performance of visible light communication employing 512-QAM N-SC-FDE and DD-LMS
    Optics Express, 2014
    Co-Authors: Yuanquan Wang, Junwen Zhang, Xingxing Huang, Yiguang Wang
    Abstract:

    In this paper, a novel hybrid time-frequency adaptive equalization algorithm based on a combination of frequency domain equalization (FDE) and decision-directed least mean square (DD-LMS) is proposed and experimentally demonstRated in a Nyquist single carrier visible light communication (VLC) system. Adopting this scheme, as well with 512-ary quadrature amplitude modulation (512-QAM) and wavelength multiplexing division (WDM), an Aggregate Data Rate of 4.22-Gb/s is successfully achieved employing a single commercially available red-green-blue (RGB) light emitting diode (LED) with low bandwidth. The measured Q-factors for 3 wavelength channels are all above the Q-limit. To the best of our knowledge, this is the highest Data Rate ever achieved by employing a commercially available RGB-LED.

  • gigabit polarization division multiplexing in visible light communication
    Optics Letters, 2014
    Co-Authors: Yuanquan Wang, Yiguang Wang, Chao Yang, Nan Chi
    Abstract:

    In this Letter, polarization division multiplexing is proposed and experimentally demonstRated for the first time that we know of, in visible light communication systems based on incoherent light emitting diodes and two orthogonal groups of linear polarizers. Spectrally efficient 16-ary quadrature amplitude modulation Nyquist single carrier frequency domain equalization is employed to obtain a maximum spectral efficiency. We achieve an Aggregate Data Rate of 1  Gb/s, with bit error Rate results for two polarization directions both below the 7% pre-forward-error-correction threshold of 3.8×10−3 after 80 cm free-space transmission. Moreover, the cross talk between x and y polarization is also discussed and analyzed.

  • theoretical and simulation analysis of a novel multiple input multiple output scheme over multimode fiber links with dual restricted launch techniques
    Optical Engineering, 2012
    Co-Authors: Yuanquan Wang, Junwen Zhang, Rongling Li, Wuliang Fang, Yufeng Shao
    Abstract:

    Different launching methods over multimode fiber (MMF) are reviewed and compared under various aspects such as coupling coefficient, mode power distribution, and bit error Rate performance. Among these, center launch and ring launch are elaboRated and chosen as the inputs of multiple-input multiple-output (MIMO) scheme for center launch exciting limited lower-order modes while ring launch exciting limited higher ones. Furthermore, we discuss the theoretical background and give a new wide-band MMF MIMO mathematical model. This paper also proposes a novel MMF MIMO system combining the dual restricted launches together with multi-segments receiving. The simulated results indicate that an Aggregate Data Rate of 20  Gb/s over 800-m graded index-multimode fiber can be achieved by using this newly established MIMO scheme.