Mixed Noisy Network Coding

Noisy Network Coding (NNC) was recently introduced, generalizing Compress-and-Forward (CF) to multiterminal networks. In this paper, we present Mixed Noisy Network Coding scheme as the generalization of NNC where part of the nodes are allowed to select Decode-and-Forward (DF) as their cooperative strategy while all nodes without exception transmit the compressed version of their observations. The compressed version of relays is exploited at each destination to decode the intended message. It is shown that Mixed NNC scheme performs potentially better than NNC. In particular, for AWGN networks it achieves a tighter ”constant gap” with respect to the cut-set bound, provided that DF relays are chosen properly.