标题： 全大规模多样性空间码用于MIMO光无线通信 显示英文标题

标题： Full Large-Scale Diversity Space Codes for MIMO Optical Wireless Communications

摘要： 在本文中，我们考虑一个受到对数正态衰落影响的多输入多输出光无线通信（MIMO-OWC）系统。 在这种情况下，开发了一个通用准则，用于设计具有最大似然（ML）检测器的全大规模分集空间码（FLDSC）。 根据我们的准则，当且仅当空间编码矩阵的所有元素均为正时，可以获得FLDSC。 特别是对于$2\times 2$MIMO-OWC与单极性脉冲幅度调制（PAM），通过巧妙利用一些可用性质以及在数论中开发一些新的有趣性质来严格解决连续和离散变量混合的最大最小问题，获得了一个满足该准则的闭式线性FLDSC。 事实上，这种特定设计不仅证明了重复码（RC）是最优线性FLDSC，还揭示了MIMO射频（RF）通信和MIMO-OWC之间的一个显著差异，即仅空间传输就足以实现完全分集性能。 计算机仿真表明，FLDSC在相同的总光功率和频谱效率下显著优于空间复用，而后者仅能获得小规模分集增益。 显示英文摘要

摘要： In this paper, we consider a multiple-input-multiple-output optical wireless communication (MIMO-OWC) system suffering from log-normal fading. In this scenario, a general criterion for the design of full large-scale diversity space code (FLDSC) with the maximum likelihood (ML) detector is developed. Based on our criterion, FLDSC is attained if and only if all the entries of the space coding matrix are positive. Particularly for $2\times 2$ MIMO-OWC with unipolar pulse amplitude modulation (PAM), a closed-form linear FLDSC satisfying this criterion is attained by smartly taking advantage of some available properties as well as by developing some new interesting properties on Farey sequences in number theory to rigorously attack the continuous and discrete variables mixed max-min problem. In fact, this specific design not only proves that a repetition code (RC) is the best linear FLDSC, but also uncovers a significant difference between MIMO radio frequency (RF) communications and MIMO-OWC that space-only transmission is sufficient for a full diversity achievement. Computer simulations demonstrate that FLDSC substantially outperforms spatial multiplexing with the same total optical power and spectral efficiency and the latter obtains only the small-scale diversity gain.