Multi-domain collaboration: Create and exploit the degrees of freedom in wireless communication

The fundamental limit of wireless communication is the tradeoff between efficiency and reliability. In order to improve system efficiency and reliability simultaneously, we have to create and explore new degrees of freedom. Multi-domain collaboration can be regarded as a systematic approach to solve this issue. From a broader and higher perspective, multi-domain is utilized to create the degrees of freedom, and collaboration is adopted to exploit the benefit of new degrees of freedom. In this paper, we illustrate this essential idea with three scenarios of link, multiuser and network. To provide an overview of the core idea of of multi-domain collaboration, we also summarize some of our recent works under the general framework from a new perspective of degrees of freedom.