Optimal user pairing to improve the sum rate of a pairwise AF multi-way relay network

In this letter, we propose a novel user pairing scheme for improving the average sum rate in an amplify and forward (AF) multi-way relay network (MWRN). We consider generalized lattice code based transmissions and derive upper bounds on the common rate and sum rate with the proposed scheme. We prove that pairing each user with the maximum average channel gain user is the optimal pairing scheme for an AF MWRN in terms of the average sum rate. Our results show that improving the overall channel conditions of the users results in greater benefits in terms of the average common rate and sum rate for the proposed pairing scheme, compared to the existing scheme.