A cooperative MMSE strategy for two-way relaying based multiuser multiplexing

We propose a minimum mean square error (MMSE) based design technique for a two way relay network that serves multiple peer-to-peer users. The algorithm aims at minimizing sum of the mean square error associated with the retrieval of symbols at multiple destinations subject to a total transmission power constraint at the relays. The problem is solved using a Lagrangian formulation of the constrained optimization problem. Through certain mathematical manipulations of the optimization problem, we suggest a method to choose the optimum Lagrange multiplier that enables full use of the transmission power at the relay.