Blind adaptive LMS multiuser detector with variable step size

In this paper, two low-complexity adaptive step size algorithms are investigated for blind adaptive multiuser detection in direct sequence code division multiple access (DS-CDMA) systems. The adaptive step size approaches are applied to a least mean squares (LMS) algorithm, which employs the Minimum output energy (MOE) criterion as the optimization objective function. Simulations are provided to compare the proposed algorithms with previously studied blind LMS and blind RLS algorithms. Results indicate that the proposed algorithms achieve superior performance, better convergence behavior and lower computational complexity in both static and dynamic environments.