Non-Orthogonal Transmission Techniques for Next-Generation Communications Systems

下一代无线系统将具有新的用例，需要最终用户的千兆体验来支持数据饥渴的无线应用（如4K流），并需要严格的能耗来支持预期的大规模连接。这样的要求对现有的无线系统基础设施提出了若干技术挑战，并且需要探索新的技术来提高下一代无线系统的频谱效率（SE）和能量效率（EE）。 传统的通信系统遵循奈奎斯特定理，并使用正交脉冲在时域和/或频域中进行传输。这简化了发射机和接收机的设计;然而，它也限制了性能。在下一代无线系统中有意地放松奈奎斯特正交性条件，一方面，将允许在相同带宽中的更高传输速率（即，改善SE）和/或将导致较低的信噪比以维持通信质量（即，改善）。另一方面，这将导致时域中相邻符号之间的符号间干扰（ISI）和/或频域中相邻子载波之间的载波间干扰（ICI）。这种创新的非正交物理层传输在文献中通常被称为时频打包（TFP）或快于奈奎斯特信令（FTNS）。该研究计划的长期目标是探索新的传输和接收技术，以提高设计SE/EE无线系统的知识水平。为了达到这个目标，建议的研究计划有以下三个短期目标：1）开发创新的低复杂度的预编码和检测技术，以消除预期的ISI和/或ICI的TFP/FTNS。2)研究TFP/FTNS与下一代无线系统的其他候选技术（如多输入多输出（MIMO）天线和/或索引调制（IM））的整合（以充分说明其优势）。3)分析和量化各种对TFP/FTNS性能的传输损害，例如射频前端的同相和正交不平衡、本机振荡器不稳定引起的相位噪声，以及功率放大器的非线性，并开发创新的信号处理技术，以补偿其有害影响。拟议的研究计划将开发新的信号处理技术，使SE/EE下一代无线系统的发展。研究计划的结果预计将吸引无线/电信行业的关注，从而促进未来的研究合作。在这项研究计划中培训的高素质人才将获得无线通信和数字信号处理方面的先进技能，以便在未来的职业生涯中脱颖而出，为加拿大的经济增长做出贡献。

Next-generation wireless systems will have novel use cases that require gigabit experience of end-users to support data-hungry wireless applications (such as 4K streaming) and stringent energy consumption to support the expected massive connectivity. Such requirements pose several technical challenges for the existing wireless systems infrastructure and there is a need to explore novel techniques to improve the spectral efficiency (SE) and energy efficiency (EE) of next-generation wireless systems. Conventional communication systems follow the Nyquist theorem and use orthogonal pulses for transmission in time and/or frequency domains. This simplifies the transmitter and receiver designs; however, it also limits the performance. Intentionally relaxing the Nyquist orthogonality condition in next-generation wireless systems, on one hand, will allow higher transmission rates in the same bandwidth (i.e., improve the SE) and/or will result in lower signal-to-noise ratio to maintain the communication quality (i.e., improve the EE). On the other hand, it will result in intersymbol interference (ISI) between adjacent symbols in the time domain and/or intercarrier interference (ICI) between adjacent subcarriers in the frequency domain. Such innovative non-orthogonal physical layer transmission is commonly referred to in the literature as time-frequency packing (TFP) or faster-than-Nyquist signaling (FTNS). The long-term objective of the research program is to explore novel transmission and reception techniques to advance the state-of-knowledge on designing SE/EE wireless systems. To achieve this target, the proposed research program has the following three short term objectives: 1) developing innovative low-complexity precoding and detection techniques to remove the expected ISI and/or ICI of TFP/FTNS. 2) investigating the integration of TFP/FTNS (to fully characterize its benefits) with other candidate technologies for next-generation wireless systems such as multiple-input-multiple-output (MIMO) antennas and/or index modulation (IM). 3) analyzing and quantifying various transmission impairments, such as, in-phase and quadrature (IQ) imbalance of radio frequency (RF) front-end, phase-noise due to local oscillators instabilities, and power amplifier nonlinearities, on the performance of TFP/FTNS and developing innovative signal processing techniques to compensate for their harmful effects. The proposed research program will develop novel signal processing techniques to enable the development of SE/EE next-generation wireless systems. The findings of the research program are expected to attract the attention of the wireless/telecommunication industry, and hence, facilitate future research collaboration. The highly qualified personnel trained in this research program will acquire advanced skills in wireless communications and digital signal processing to excel in their future careers and contribute to Canada's economic growth.