Physical-layer network coding in optical networks

Physical-Layer Network Coding (PNC) is a promising technique to improve the network throughput of full-duplex transmission in a wireless two-way relay channel. Here, we explore the application of PNC in optical systems and networks. Two transmitted optical signal frames are simply added together to form an optical PNC-coded composite frame, which shares the same network channel/resource. At their destined node, the composite signal is directly-detected, before being decoded by subtracting one of the two transmitted signal frames, which is either already known or stored locally, from the received PNC-coded composite frame.