The concept of physical-layer network coding (PNC) was proposed in 2006 for application in wireless networks. Since then it has developed into a subfield of communications and networking with a wide following. This book is a primer on PNC. It is the outcome of a set of lecture notes for a course for beginning graduate students at The Chinese University of Hong Kong. The target audience is expected to have some prior background knowledge in communication theory and wireless communications, but not working knowledge at the research level. Indeed, a goal of this book/course is to allow the reader to gain a deeper appreciation of the various nuances of wireless communications and networking by focusing on problems arising from the study of PNC. Specifically, we introduce the tools and techniques needed to solve problems in PNC, and many of these tools and techniques are drawn from the more general disciplines of signal processing, communications, and networking: PNC is used as a pivot to learn about the fundamentals of signal processing techniques and wireless communications in general. We feel that such a problem-centric approach will give the reader a more in-depth understanding of these disciplines and allow him/her to see first-hand how the techniques of these disciplines can be applied to solve real research problems. As a primer, this book does not cover many advanced materials related to PNC. PNC is an active research field and many new results will no doubt be forthcoming in the near future. We believe that this book will provide a good contextual framework for the interpretation of these advanced results should the reader decide to probe further into the field of PNC.

Soung Chang Liew, The Chinese University of Hong Kong
Professor Soung Chang Liew received his S.B., S.M., E.E., and Ph.D. from the Massachusetts Institute of Technology. From March 1988 to July 1993, he was at Bellcore (now Telcordia), New Jersey, where he engaged in Broadband Network Research. He has been a Professor at the Department of Information Engineering, the Chinese University of Hong Kong (CUHK), since 1993. He is currently also a Co-Director of the Institute of Network Coding at CUHK. Prof. Liew's research group won the best paper awards in IEEE MASS 2004 and IEEE WLN 2004. Separately, TCP Veno, a version of TCP to improve its performance over wireless networks proposed by Prof. Liew's research group, has been incorporated into releases of Linux OS. In addition, Prof. Liew initiated and built the first inter-university ATM network testbed in Hong Kong in 1993. More recently, Prof. Liew's research group pioneered the conceptualization and prototyping of Physical-layer Network Coding, a new paradigm for communications and networking. Prof. Liew is the holder of ten U.S. patents and a Fellow of IEEE, IET and HKIE. He currently serves as an Editor for IEEE Transactions on Wireless Communications and Ad Hoc and Sensor Wireless Networks. He is the recipient of the first Vice-Chancellor Exemplary Teaching Award in 2000 and the Research Excellence Award in 2013 at the Chinese University of Hong Kong.

Lu Lu, The Chinese University of Hong Kong
Professor Lu Lu received his B.E. from the University of Science and Technology of China (USTC) in 2007, and his Ph.D. from The Chinese University of Hong Kong (CUHK), in 2012. He was a postdoctoral fellow in the Institute of Network Coding at CUHK from 2012 to 2014. Since 2014, he has been a research assistant professor at the Institute of Network Coding, CUHK. Prof. Lu's research interests include wireless communications, multi-user detection, physical-layer network coding, and software-defined radios. Prof. Lu is the recipient of the Faculty's Outstanding Ph.D. Thesis Award and the Postgraduate Research Output Award both in 2013 at CUHK.

Shengli Zhang, Shenzen University
Professor Shengli Zhang received his B. Eng. in electronic engineering and M. Eng. in communication and information engineering from the University of Science and Technology of China (USTC), Hefei, China, in 2002 and 2005. He received his Ph.D. from the Department of Information Engineering, the Chinese University of Hong Kong (CUHK) in 2008. He was a research associate at CUHK from 2008 to 2009. In May 2009, he joined the Communication Engineering Department, Shenzhen University, where he now holds an associate professorship. From 2014 to 2015, he was a visiting associate professor at Stanford University. Prof. Zhang's research interests include physical layer network coding, known interference cancellation, and cooperative wireless networks.

Table of Contents
A Brief Tutorial of PNC
Communication Theory and Signal Processing in PNC Systems
Information-Theoretic Analysis of PNC Systems
PNC Networks
PNC Implementations
References
Authors' Biographies