For both O-OFDMA and O-SCFDMA, Hermitian symmetry (HS) constraint is imposed in frequency-domain (FD) to obtain a real-valued time-domain (TD) signal for intensity modulation-direct detection (IM-DD) implementation of VLC. Howbeit, HS results in an increase of PAPR for O-SCFDMA. In ...
Fourier transform (FT)Hermitian symmetry (HS)peak-to-average power ratio (PAPR)wavelet transform (WT)Optical orthogonal frequency-division multiplexing (OFDM) has proven to be an effective technique for the visible light communication (VLC) system in which data is sent and received through the ...
investigate the dependence of fractional Lévy index (α) on the symmetry breaking of solitons in detail. And the stabilities of fundamental symmetric soliton, asymmetric solitons, as well as the first excited states are explored. Moreover, The management of optical field propagation is achieved by ...
In general, non-Hermitian contributions, such as dissipation, break the Hermitian time-reversal symmetry. However, one might find a combined parity–time (PT) symmetry6, which allows for a completely real energy spectrum, if unbroken. The discovered exotic behaviour at the critical point of PT ...
关键词: group algebra positive semi-definiteness symmetry operator DOI: 10.1016/S0024-3795(99)00044-0 被引量: 18 年份: 1999 收藏 引用 批量引用 报错 分享 全部来源 免费下载 求助全文 全文购买 Elsevier (全网免费下载) Elsevier Semantic Scholar 掌桥科研 Ingenta 查看更多 相似文献 参考文献 引证文献...
Notes 1. The first theoretical proposal of PT-symmetry in optics was given in [12]. 2. We shall restrict to reflexive Banach spaces since in this case the formulation is simpler and more similar to the Hilbert space case, see [23]....
We propose a novel discrete Fourier transform (DFT) spread M-ary amplitude shift keying (M-ASK) coherent optical orthogonal frequency division multiplexing (CO-OFDM) with a Hermitian symmetry system to mitigate nonlinear effects by reducing the peak-to-average power ratio (PAPR) of the OFDM ...
To produce real-valued OFDM signal for VLC, Hermitian-symmetry (HS) is needed during the inverse-fast-Fourier-transform (IFFT) encoding process. However the HS requirement doubles the IFFT/FFT size and increase the encoding complexity. Non-Hermitian symmetry (NHS)-OFDM schemes are proposed, but...
Spectral responsivity, R(E), of the PV-cell was measured by performing Fourier Transform Photocurrent Spectroscopy (FTPS). EQE spectrum was obtained from the spectral responsivity as EQE(E) = \(\frac{R(E).E}{q}\). I–V characterization of the cell was performed using a source measur...
This can result in the appearance of a non-symmetry-protected non-Hermitian Weyl phase characterized by bulk Fermi arc which can be manipulated by magnetization direction29. While, in the latter case, the gap is not robust and can be filled by potential scattering30. Recently, it has been ...