Physical-Layer Network Coding: Research Trends and Challenges

摘要

The unreliability and the broadcast nature of the wireless communications appear to set a fertile ground for developing solutions based on network coding. The key idea of wireless network coding is to combine multiple communication flows at the relay nodes and use the wireless broadcast transmission to convey the combined flow to multiple destination nodes. Such an approach exhibits a significant throughput improvement when considering bi-directional traffic flows. The physical layer network coding (PLNC) achieves further improvement by combining the flows at the physical layer through the wireless multiple access channel. While its gain in terms of throughput is significant, there are many technical problems to be solved for PLNC to be applied to practical and general wireless networks. In this article, we introduce the state-of-the-art of the research on PLNC. The PLNC requires a fresh look on the protocol design and layering and we outline challenges to be tackled on when designing protocols that utilize PLNC in wireless networks.