Multi-user Detection Based on the Accelerated EM Algorithm

Multi-user detection (MUD) is one standard of 3G, which can effectively reduce the multiple access interference (MAI) and increase the system capacity. The Expectation-Maximization (EM) iterative algorithm is commonly used in recent years for missing data, which could be applied to MUD system. But the EM algorithm has a fatal weakness that its slow convergence speed. The new accelerated EM Algorithm is proposed in this paper, which is based on the EM Algorithm and Newton-Raphson algorithm, in order to improve the convergence speed. The proposed algorithm is applied to Multi-user Detection (MUD). The simulation results show that the performance of accelerated EM algorithm is almost as good as the standard EM algorithm in Gaussian noise. The proposed algorithm has better convergence speed than standard EM algorithm.