Auto-encoder Based Analog Network Coding for Free-Space Optical Two-Way Communications

This paper proposes an autoencoder-based analog network coding (ANC) in a two-way relay channel of laser communication to reduce the noise of unstable atmospheric channel. We regard the exchange of massage from one node to another as two autoencoder networks. Through joint training of the two autoencoder networks, the system can obtain almost 4dB BER performance gain compared with the conventional ANC system, and the Hamming-coded system BER performance is further improved by 2dB. To further evaluate the performance of proposed system, we change the numbers of hidden layers to find the relationship between the number of hidden layers and the bit error rate.