Improved blind adaptive detection for synchronous multiuser CDMA systems

In this paper, the convergence behavior of blind multiuser linear detectors in code division multiple access (CDMA) systems based on minimum output energy (MOE) and constant modulus algorithm (CMA) is analyzed and compared. A modified MOE detector is proposed which is shown to converge to the conventional decorrelator. With proper initialization, CMA can lock onto the desired user while nulling all other interfering users. Simulation results are presented to demonstrate that CMA has higher capacity with minimal noise enhancement and is more robust to change of users.