Convergence Constrained Multiuser Transmitter-Receiver Optimization in Single-Carrier FDMA

Convergence constrained power allocation (CCPA) in single-carrier multiuser (MU) single-input multiple-output (SIMO) systems with turbo equalization is considered in this paper. In order to exploit the full benefit of the iterative receiver, its convergence properties need to be taken into account also at the transmitter side. The proposed scheme can guarantee that the desired quality of service (QoS) is achieved after a sufficient number of iterations. We propose two different successive convex approximations for solving the non-convex power minimization problem subject to user specific QoS constraints. The results of an extrinsic information transfer (EXIT) chart analysis demonstrate that the proposed CCPA scheme can achieve the design objective. Numerical results show that the proposed schemes can achieve superior performance in terms of power consumption as compared to linear receivers with and without precoding, as well as to the iterative receiver without precoding.