Spatial correlation for transmitters in spatial MIMO optical wireless links with Gaussian-beam waves and aperture effects
Spatial correlation for transmitters in spatial MIMO optical wireless links with Gaussian-beam waves and aperture effects
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DOI：
10.1016/j.optcom.2012.09.022
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发表时间：
2013-01
影响因子：
2.4
通讯作者：
Zhixiao Chen;Song Yu;Tianyi Wang;Guohua Wu;Hong Guo;W. Gu
中科院分区：
文献类型：
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作者：
Zhixiao Chen;Song Yu;Tianyi Wang;Guohua Wu;Hong Guo;W. Gu
研究了空间多输入多输出(MIMO)系统中来自一对发射机的信号之间的空间相关性。在弱湍流条件下，给出了考虑高斯波和接收器孔径效应的空间相关函数的一般公式。基于解析表达式，我们发现空间相关性随距离的增大而减小，但随接收孔径大小、湍流强度和波长的增大而增大。尤其是接收机孔径平均效应可以明显提高相关系数。结果还表明，减小光束宽度通常会降低空间相关性，且会聚光束的空间相关性低于平行光束。结果表明，菲涅耳比大于1的高斯光束在减小空间相关性和光束闪烁方面具有优势。
The spatial correlation between signals arising from a pair of constituent transmitters in a spatial multiple-input–multiple-output (MIMO) system is investigated. General formulations for the spatial correlation functions considering Gaussian-beam waves and receiver aperture effects are given under weak turbulence condition. Based on the analytical expressions, we find that spatial correlation decreases with separation distance, but increases with receiver aperture sizes, turbulence strength and wavelengths. In particular, receiver aperture averaging effects can evidently increase the correlation. It is also shown that decreasing the beam widths can generally reduce the spatial correlation, and convergent beams have lower spatial correlation than their collimated counterparts. It is found that Gaussian beams with the Fresnel ratios larger than 1 have advantages in reducing both the spatial correlation and the beam scintillations.