A Practical Compress-and-Forward Relay Scheme Based on Superposition Coding

Compress-and-forward (CF) is one of the protocols in cooperative communication and has drawn much attention. In CF scheme, the relay compresses and transmits the received signals to the destination, where Wyner-Ziv coding is considered as an efficient way to compress the signal with side information available. Since the current research of superposition coding for Wyner-Ziv problem only remains in theory, we design a practical CF scheme in half-duplex mode by using the technique of superposition coding and provide specific coding strategy for it. The relay compresses the received signal by the quantization method based on superposition coding, and then the destination performs a joint decoding to recover the original message. Simulations show that our proposed scheme outperforms the conventional CF scheme with scalar quantization at the relay. This coding strategy can be easily extended to the scenarios of fading channels, which are more practical in wireless communication.