Low-Complexity Near-Optimal Codes for Gaussian Relay Networks
  We consider the problem of information flow over Gaussian relay networks. Similar to the recent work by Avestimehr \emph{et al.} [1], we propose network codes that achieve up to a constant gap from the capacity of such networks. However, our proposed codes are also computationally tractable. Our main technique is to use the codes of Avestimehr \emph{et al.} as inner codes in a concatenated coding scheme. 
Theodoros K. Dikaliotis, Hongyi Yao, Salman Avestimehr, Sidharth   Jaggi, Tracey Ho
cs.IT cs.NI math.IT