High spectral efficiency has been an ongoing quest in wireless networks since their inception, due to the reality of limited spectrum. This project is proposed at a time when network coding has been envisioned to bring fundamental changes to the design of communication networks, where spectrum can be more efficiently utilized and interference can be better coped with. The aim of this proposal is to systematically study network coding at the physical layer, where we will not only characterize the fundamental limits of physical layer network coding, but also design practical digital signal processing (DSP) algorithms to realize the performance gain promised by those theoretic results. The project involves the Fellow initially working for 12 months in Princeton University, USA, to receive state of the art training on a specific project in wireless network coding. This will then be followed by 12 months in Newcastle University UK, for the integration of the skills and knowledge gained in Princeton. The results of the project will have a broad impact across a range of areas including wireless communications, signal processing and information theory, etc. Furthermore such an insight obtained from the project provides a precise guideline for the efficient design of practical and reliable communications systems, and hence is important to various applications, including broadband mobile communications, wireless sensor networks, etc.