Multi-mode all-digital transmitters for software defined radio applications

先进的无线通信系统要求多标准功能更加无处不在、移动性、灵活性和安全性。这就要求开发软件定义的无线电收发信机。到目前为止，人们已经开展了广泛的研究活动来设计这种多频段收发机的射频前端。本文的主要研究内容是接收机的设计。相反，发射端仍处于早期研发阶段。传统的发射机射频前端结构是基于模拟的，因此很难重新配置，并且容易受到噪声、非线性和硬件损伤的影响。一个更有吸引力的选择是将设计转移到数字领域。这项合作研究计划旨在利用最新的半导体GaN技术，为先进的通信系统开发创新的全数字射频发射机。目标结构是基于开关模式的射频功率放大器，使其有可能达到极高的功率效率水平和采用脉冲调制技术的高速数字信号处理模块。拟议的研究项目旨在实现两个主要目标：

Advanced wireless communication systems require multi-standard capabilities to be more ubiquitous, mobile, agile, and secure. This calls for the development of software defined radio transceivers. So far, extensive research activities have been carried out to design the RF front-end of such multi-band transceivers. This preliminary focused on the receiver design. Conversely, the transmitter side is still at the early research and development stages. Conventional transmitter RF front-end architectures are analog-based and therefore are hard to reconfigure and are prone to noise, nonlinearity and hardware impairments. A more compelling alternative is to move the design to digital domain. This collaborative research proposal aims at developing innovative all-digital RF transmitters for advanced communication systems using the latest semi-conductor GaN technology. The targeted architecture is based on switching-mode RF power amplifier that makes it possible to attain extremely high power efficiency levels and high speed digital signal processing block using pulse modulation technique. The proposed research project aims at two main objectives: