Physical-Layer Network Coding in Shallow Sea Underwater Acoustic Channels

To improve the limited-bandwidth in shallow underwater acoustic communication, we propose to apply the physical-layer network coding (PNC) to this communication system. This paper analyzes the model of shallow underwater acoustic channel – “Ray Model” and uses the adaptive equalization technique to eliminate the inter-symbol interference (ISI). Besides, we also study the principle of PNC and research the demodulation and mapping scheme in relay node. Finally, we combine the channel model and PNC technique in two-way relay communication (TWRC) system. The performance simulation of PNC is compared with the traditional multi-hop scheme and network coding (NC) scheme. The result shows that PNC scheme can improve the throughput of system but do not increase the bit error rate (BER) in the shallow underwater acoustic communication. It provides a new research direction for shallow underwater acoustic communication, and also expands a new field for PNC applications.