A Low-complexity Linear Receiver for Multi-User MIMO SC-FDMA Systems

Single carrier frequency divison multiple access (SCFDMA) has been proposed for the uplink of 4G mobile standards (LTE and LTE-A). LTE-A networks will be characterized by a large number of small cells (radius: 200-300 meters), exploiting multi-user Multiple Input - Multiple Output (MU-MIMO) in order to boost spectral efficiency and user capacity. The potential of MU-MIMO techniques is enormous. However, the joint detection of multiple signals coming from users belonging to different cells is still an open challenge. In this paper, we are proposing a linear multi-user detection (MUD) algorithm for MU-MIMO SCFDMA systems, based on minimum-conditional bit-error-probability (MCBEP), criterion. The step ahead with respect to state-of-the-art is related to the implementation of a MUD strategy based on the minimization of the bit-error-probability obtained at an affordable computational complexity, linear with the number of transmitting array elements. Simulation results demonstrate that the proposed MCBEP MUD clearly outperforms state-of-the-art MUD based on Signal-plus-Interference-to-Noise (SINR) maximization (namely: ideal-MMSE and LMS-based MMSE MUD), significantly approaching theoretical performance bounds.