Multiband multicarrier transmitters for the next generation of software defined wireless base stations

无线通信一直是人类历史上发展最快的技术之一，新的复杂标准不断涌现，以满足日益超级连接的世界对更快数据速率的需求。然而，每次出现新的标准时，运营商都被迫建立一个新的专用网络，拥有成本相当高。因此，无线通信正经历着标准生命周期的极大缩短和投资风险的加剧。该项目旨在应用软件定义无线电(SDR)的前沿技术来研究新一代灵活和可重新配置的无线基站，这些基站能够(I)在广泛的频段上运行，以及(Ii)根据不同的标准发送或接收信号。新一代多频段和多标准SDR基站将实现更统一的无线基础设施，具有更好的完整性、更长的网络寿命和低投资风险。它还将通过采用智能动态频谱分配来提高网络利用率。该项目将重点开发新型多频段和多载波(MBMC)发射机，这是成功实现SDR基站的最具挑战性的设计标准。因此，研究的第一步将是寻找一种通用的创新MBMC发射机体系结构。该项目还将研究设计多频带匹配网络和阻抗转换器的系统方法。这些将在稍后应用于采用GaN晶体管技术的MBMC AB类功率放大器(PA)的设计中。随后，MBMC-AB类功率放大器的成功实现将触发一个更令人兴奋和更具挑战性的目标，即开发MBMC Doherty放大器来提高SDR基站的效率。此外，还将分析MBMC发射机表现出的失真的来源，以便开发新的物理驱动行为模型和基于预失真的线性化装置，以满足无线标准所规定的严格的线性要求。

Wireless communications have been among the fastest-growing technologies in human history with relentless emergence of new sophisticated standards to satisfy the demands for faster data rates of the increasingly hyperconnected world. However, each time a new standard emerges, carriers are forced to build a new dedicated network with considerable cost of ownership. Hence, wireless communications are experiencing an extreme shortening of standards lifecycle and intensification in investment risks. This project aims at the application of the leading edge technology of Software Defined Radios (SDR) for the investigation of new generation of flexible and reconfigurable wireless base stations capable of (i) operating over a wide range of frequency bands, and (ii) transmitting or receiving signals according to dissimilar standards. This new generation of multiband and multi-standard SDR base stations will enable a more unified wireless infrastructure that features an improved integrity, extended networks lifespan and low investments risks. It will also lead to more efficient network utilization by employing intelligent dynamic spectrum allocation. This project will focus on the development of novel multiband and multicarrier (MBMC) transmitters which represent the most challenging design criteria in the successful realization of SDR base stations. Therefore, the first step of the research will be geared towards finding a common innovative MBMC transmitter architecture. The project will also investigate a systematic approach for the design of multiband matching networks and impedance transformers. These will later be applied in the design of MBMC class-AB power amplifiers (PA) using GaN transistor technology. Subsequently, the successful realization of the MBMC class-AB PAs will trigger a more exciting and challenging objective aiming at the development of MBMC Doherty amplifier to improve the efficiency of the SDR base stations. In addition, sources of distortions exhibited by the MBMC transmitters will be analyzed in order to develop novel physical driven behavioural models and predistortion based linearizers in order to meet the stringent linearity requirements imposed by the wireless standards.