基于认知与极化信号处理的功放节能研究

The aim of this research project is to solve the problem of Power Amplifiers' (PAs) low energy efficiency and high energy consumption, which are introduced by the strict requirement of operating at linear region, in wireless communications. A significant feature that the States of Polarization (SoP) are not impacted by PAs nonlinear distortion has been explored by our preliminary research. Therefore, by introducing SoP as the information-bearing parameter, a novelty scheme that can release PAs to operate at nonlinear region even the saturation point to acquire high energy efficiency is proposed. The research will be developed according to the following two steps. Firstly, the methods and technologies of bearing information by SoP are investigated; the channel depolarization feature of wireless transmission is analyzed, and the compensation algorithms are researched; PAs' power efficiency improvement is then assessed. Secondly, to further decrease energy consumptions, a joint-modulation method combining polarization and existing amplitude/phase modulation is proposed; the superiorities of re-configuration in cognitive radio and intelligent optimal decision-making are adopted to analyze the cognitive-based joint-modulation energy efficiency optimization model and algorithm. Rely on this project, the problem of PAs' low energy efficiency and high energy consumption, which is due to operating in linear region for avoiding nonlinear distortion, will be resolved. A theory system, which could reduce PAs energy consumption by using SoP to bear information, is expected to be creatively established in the field of energy conservation in wireless communications.

针对功率放大器为避免非线性失真只能工作在线性区导致的低效率、高能耗问题，课题开创性地提出利用信号的极化状态不受非线性影响的特性实现极化状态承载传输信息，使功放工作在高效率的非线性区，甚至饱和点的思想。课题围绕如何利用极化状态承载信息实现功放节能展开。首先研究新型的极化状态承载信息方法，并针对无线信道特有的去极化效应，探索相应的抗去极化效应补偿算法，在此基础上分析评估能量效率提升的理论上界；其次，为进一步降低能耗，课题提出将极化状态与传统的幅度相位调制方法联合起来，结合认知无线电重配置和智能寻优决策的优势，研究新型的基于认知的联合调制能量效率优化模型及算法。课题巧妙地解决了功放为避免非线性失真，工作在低效率、高能耗线性区的科学难题，有望在无线通信节能领域建立采用极化状态承载信息方法解决功放高能耗问题的新理论体系。

针对功率放大器为避免非线性失真只能工作在线性区导致的低效率、高能耗问题，项目围绕如何利用极化状态承载信息实现功放节能展开，从无线信号极化状态控制机制与算法及其极化状态不受功放非线性影响特性、极化状态调制解调方法与抗无线信道去极化效应机制与算法、基于认知的极化状态与幅度相位联合调制机制等方面进行研究。研究成果为发表高水平学术论文56篇，其中在IEEE Communications Surveys & Tutorials、IEEE Transctions on Wireless Communication、IEEE Transactions on Vehicular Technology等通信领域顶级期刊发表SCI论文20篇，申请发明专利10项并获得1项授权，发表专著1部，培养研究生30余人。.项目首先从理论和仿真两个方面验证了极化状态不受功放非线性影响这一特性；在传统无线收发机的基础上设计了基于数字信号处理的极化发射机和基于虚拟极化接收和Stokes矢量的接收机，完成了极化调制的发射和接收判决；建立了窄带和宽带无线去极化信道模型和一系列信道感知算法，并在此基础上提出了多种抗去极化效应算法；建立了基于认知的极化状态和幅度相位联合调制及其功放能量效率模型，通过自适应、差分进化算法等实现了功放能效的大幅提升。与传统对抗功放非线性的预失真方法相比，对于不同的数据速率需求，项目所提基于极化状态和幅度相位联合调制的功放能效优化方案在线性区时能够提升8%的功放能效，在非线性区时能够提升25%；在相同的误码率性能要求下，这一优势可提升至35%。.项目开创性地提出基于认知与极化信号处理的功放节能研究，通过建立功放工作在非线性区的极化状态承载信息理论与方法，为解决功放为避免非线性失真导致的低效率高能耗这一难题开辟了一条新的途径。项目研究创建了极化状态调制新方法，创新性地构建了认知与节能相结合的研究框架，逐渐在无线通信节能研究领域建立了一个基于极化调制解决功放高能耗问题的新理论体系。