Degrees of freedom of asymmetrical multi-way relay networks
Fan Sun, Elisabeth de Carvalho · 2011
In this paper, we introduce an asymmetrical multi-way relay channel where a base station conveys independent symbols to K different users while receiving independent symbols from the users. In this network, user i Shas Miantennas (i ∈ [1, …, K]), the base station has Σi=1KMiantennas and the relay is equipped with NRantennas. To study the capacity of this network, the degree of freedom (DOF) is characterized to be 2 Σi=1KMiif NR≥ Σi=1KMi. The DOF implies that the number of symbols any transmitter can deliver and receive is equivalent to its number of antennas. The DOF is achievable with a proposed joint multiple access and broadcast precoding design using the signal space alignment concept.