Journals: Coexisting Linear and Widely Linear Transceivers in the MIMO Interference Channel Lagén Morancho, A. Agustin de Dios and J. Vidal ManzanoAbstractRecent results have shown the benefits of widely linear precoding (WLP) in the MIMO interference channel (MIMO IC) assuming that all transmitters can follow the same strategy. Motivated by a transitional scenario where legacy linear transmitters coexist with widely linear ones, this work investigates the general Kuser MIMO IC in a heterogeneous (linear and widely linear) transmitter deployment. In particular, we address the maximization of the weighted sumrate (WSR) for (widely) linear transmit filters design through the use of the complexvalued formulation. Since the maximum WSR problem is nonconvex, and thus difficult to be solved, we formulate an equivalent minimum weighted mean square error problem that allows deriving closedform expressions for (widely) linear transceivers. Then an iterative procedure is proposed, which is proven to reach a stationary point of the maximum WSR problem. Simulations show that the proposed procedure allows increasing the sumrate as compared to coordinated linear transceiver schemes. The gains are larger and significant in two different nonexclusive conditions: as the interference level increases or when the number of antennas is low. Full document 
