Sixty Years of Coherent Versus Non-Coherent Tradeoffs and the Road From 5G to Wireless Futures
Sixty Years of Coherent Versus Non-Coherent Tradeoffs and the Road From 5G to Wireless Futures
复制标题
DOI：
10.1109/access.2019.2957706
复制
发表时间：
2019-12
期刊：
影响因子：
3.9
通讯作者：
Chao Xu;Naoki Ishikawa;R. Rajashekar;S. Sugiura;R. Maunder;Zhaocheng Wang;Lie-liang Yang;L. Hanzo-L.-Hanz
中科院分区：
文献类型：
--
作者：
Chao Xu;Naoki Ishikawa;R. Rajashekar;S. Sugiura;R. Maunder;Zhaocheng Wang;Lie-liang Yang;L. Hanzo-L.-Hanz
回顾了多输入多输出（MIMO）系统中相干与非相干权衡的60年和相干与非相干权衡的20年。此外，自适应的优点进行了讨论。更明确地说，为了在统一平台中支持不同应用的各种通信需求，5G新无线电（NR）提供了前所未有的自适应性，但代价是大量的信令开销，这些信令开销消耗了功率和宝贵的频谱资源。实现有益的相干与非相干权衡能够减少信道估计的导频开销，同时依赖于低复杂度检测器，特别是在高移动性场景中。此外，由于能量效率在操作和未来网络中都具有显著的重要性，因此在强大的指数调制（IM）物理学之后，我们设想了一种整体自适应物理学，其达到最适当的相干/非相干、单天线/多天线和分集/复用权衡，其中RF链的数量，信号传输的峰均功率比（PAPR）和信号检测所容许的最大干扰量都被考虑在内。我们证明，这种智能的三重自适应性在下一代毫米波和太赫兹解决方案的应用中，在空间-空中-地面综合网络中，在全双工技术和其他复杂的信道编码辅助系统设计中提供了显着的好处，其中强大的机器学习算法预计将以最少的人为干预做出关于最佳操作模式的自主决策。
Sixty years of coherent versus non-coherent tradeoff as well as the twenty years of coherent versus non-coherent tradeoff in Multiple-Input Multiple-Output (MIMO) systems are surveyed. Furthermore, the advantages of adaptivity are discussed. More explicitly, in order to support the diverse communication requirements of different applications in a unified platform, the 5G New Radio (NR) offers unprecendented adaptivity, abeit at the cost of a substantial amount of signalling overhead that consumes both power and the valuable spectral resources. Striking a beneficial coherent versus non-coherent tradeoff is capable of reducing the pilot overheads of channel estimation, whilst relying on low-complexity detectors, especially in high-mobility scenarios. Furthermore, since energy-efficiency is of salient importance both in the operational and future networks, following the powerful Index Modulation (IM) pholosophy, we conceive a holistic adaptive pholosophy striking the most appropriate coherent/non-coherent, single-/multiple-antenna and diversity/multiplexing tradeoffs, where the number of RF chains, the Peak-to-Average Power Ratio (PAPR) of signal transmission and the maximum amount of interference tolerated by signal detection are all taken into account. We demonstrate that this intelligent tripple-fold adaptivity offers significant benefits in next-generation applications of mmWave and Terahertz solutions, in space-air-ground integrated networks, in full-duplex techniques and in other sophisticated channel coding assisted system designs, where powerful machine learning algorithms are expected to make autonomous decisions concerning the best mode of operation with minimal human intervention.