排序方式: 共有17条查询结果,搜索用时 15 毫秒
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We propose a configuration of a wavelength division multiplexing (WDM)-visible light communication (VLC) system using orthogonal frequency division multiplexing (OFDM) modulation and an adaptive Nyquist windowing of the OFDM signal in the receiver. Based on this configuration, we demonstrate a 750-Mb/s WDM-VLC transmission based on RGB light-emitting diode (LED) with a distance of 70 cm. The measured bit error rate (BER) for all channels are under the pre-forwaxd error correction limit of 3,8 × 10-3. The BER performances of all the channels of the proposed WDM-VLC system show considerable improvement compared with those of the system without Nvauist windowing. 相似文献
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提出了一种新型的基于串行结构的最小频移键控调制技术,产生了相位连续,频谱宽度窄,每码元时间有两次π/2相移,类似于传统最小频移键控调制信号,给出了该调制方案的理论推导,并将其应用于8进制的多维多阶调制系统中。理论和仿真分析了不同的8进制调制方案在频谱特性,残留色散容限,自相位调制容限的不同,还分析了其受到系统滤波带宽的影响。最后仿真实现了通过350km的色散完全补偿的光纤120Gb/s的数据传输。 相似文献
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We propose an integral imaging system that uses three lens arrays, including two convex lens arrays and a concave lens array. Compared with the conventional integral imaging system, the proposed system can remarkably enhance the viewing angle. The maximum viewing angle can be enlarged to 48~, which is 4.8 times wider than that of the conventional system. The principle of the proposed system is elucidated, and the experimental results are presented in this letter. 相似文献
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We propose a novel scheme for optical frequency-locked multi-carrier generation based on a directly modu- lated laser (DML) and a phase modulator (PM) in cascade through synchronous sinusoidal radio frequency (RF) signal. The optimal operating zone for the cascaded DML and PM scheme is determined via theoreti- cal analysis and numerical simulation. We demonstrate 16 optical subcarriers can be successfully generated based on the cascaded DML and PM scheme in the optimal zone. The generated 16 optical subcarries have frequency spacing of 12.5 GHz and power difference of less than 3 dB. These results agree well with those of the numerical simulation. We also demonstrate intensity modulation and direct detection (IM-DD) based on one of the 16 generated optical subcarriers. After 20-km single-mode fiber-28 (SMF-28) transmission, the bit-error ratio (BER) of 1×10^-9 can be attained for both 3.125- and 12.5-Gb/s bit rates. 相似文献
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相干且频率锁定的正交多载波光源产生技术在光通信领域有着诸多应用,能广泛用于微波光子学、全光信号处理以及波分复用(WDM)技术和正交频分复用(OFDM)技术.互联网数据业务的快速增长使得超宽带大容量骨干网传输技术越来越受到世界各国的重视,而要实现Tb/s超大容量传输,目前使用的最主要的方法是光的波分复用(WDM)或正交频分复用(OFDM)技术.作为实现光WDM或OFDM的一项关键技术,相干和频率锁定的正交多波长光源技术引起了国内外各大科研机构的强烈关注.介绍了国内外多载波技术的现状以及多载波产生的多种方案,并对每一个方案进行了对比分析,为未来的研究提供了一些参考. 相似文献
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We propose and experimentally demonstrate a novel scheme to realize polarization-division-multiplexing quadrature-phase-shift-keying (PDM-QPSK) signal transmission over fiber, wireless and fiber at Wband (75-110 GHz). The generation of polarization multiplexing millimeter-wave (mm-wave) wireless signal is based on the photonic technique. After 20-km fiber transmission, polarization diversity and heterodyne beating are implemented to convert the polarization components of the polarization-multiplexing signals from the optical baseband to W-band so that up to 16 Gb/s mm-wave signals can be delivered over 2-m 2~2 multiple-input multiple-output (MIMO) wireless link. At the receiver base station (BS), polarization combination reconstructs the PDM-QPSK signal which is then launched into another 20-km fiber. In the experiment, coherent detection is introduced to improve receiver sensitivity and constant modulus algorithm (CMA) is applied for polarization de-multiplexing. The bit-error-ratio (BER) for 16-Gb/s PDM- QPSK signal delivery is below the forward-error-correction (FEC) threshold of 3.8× 10-3 with the optical signal-to-noise ratio (OSNR) above 11.8 dB. 相似文献
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