Non-uniform constellations (NUCs) successfully utilize geometrical shaping to approach the Shannon capacity, but increase demapping complexity. In this paper, enhanced non-uniform constellations for low-complexity and high-capacity communications are investigated and addressed in two steps: low-complexity demappers for fixed constellations and the constrained design of enhanced NUCs. First, simplified demappers for NUCs are studied, and modified virtual point searching (VPS)-based demappers are proposed. Theoretical analysis and numerical results show that the proposed modified VPS-based demappers reduce demapping complexity with negligible performance degradation. Secondly, two shaping constraint schemes are proposed to NUC design for the purpose of low complexity and high capacity. NUCs optimized under the proposed constraints outperform the uniform constellations, and the proposed demappers have good applicability to the optimized NUCs. The proposed NUC design constraint schemes and simplified demappers enable solutions to achieve low-complexity high-capacity communication.

中文翻译：

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使用低复杂度解映射器实现高容量通信的增强型非均匀星座


非均匀星座（NUC）成功地利用几何整形来接近香农容量，但增加了解映射的复杂性。在本文中，通过两个步骤研究和解决了用于低复杂度和高容量通信的增强型非均匀星座：固定星座的低复杂度解映射器和增强型NUC的约束设计。首先，研究了 NUC 的简化解映射器，并提出了基于改进的虚拟点搜索（VPS）的解映射器。理论分析和数值结果表明，所提出的改进的基于 VPS 的解映射器降低了解映射复杂性，而性能下降可以忽略不计。其次，为了实现低复杂度和高容量的目的，提出了两种整形约束方案来进行NUC设计。在所提出的约束下优化的 NUC 优于均匀星座，并且所提出的解映射器对优化的 NUC 具有良好的适用性。所提出的 NUC 设计约束方案和简化的解映射器使解决方案能够实现低复杂度高容量通信。