Science and Research Branch, Islamic Azad University, Hesarak, Tehran 14778-93855, Iran
Department of Electrical Engineering, Shahed University, Persian gulf freeway, Tehran 33191-18651, Iran
Department of Biomedical Engineering, Amirkabir University of Technology, 424 Hafez Ave., Tehran 15875-4413, Iran
Department of Electrical Engineering, Iran University of Science & Technology, Narmak, Tehran 16846-13114, Iran
Signal and Image Processing Institute, Department of Electrical Engineering, University of Southern California, Los Angeles, CA 90089,USA
In this paper, we present an efficient evolutionary algorithm for Multiuser Detection (MUD) problem in Direct Sequence-Code Division Multiple Access (DS-CDMA) communication systems. The optimum detector for MUD is the Maximum Likelihood (ML) detector, but its complexity is very high and involves an exhaustive search to reach the best fitness of the transmitted and received data. Thus, there has been much interest in suboptimal multiuser detectors with less complexity and reasonable performance. The proposed algorithm is a modified Genetic Algorithm (GA) which reduces the dimension of the search space and provides a suitable framework for future extension to other optimization problems, especially for high dimensional ones. This algorithm is compared to ML and two famous model-free optimization methods: Particle Swarm Optimization (PSO) and Ant Colony Optimization (ACO) algorithms which have been used for MUD in DS-CDMA. The simulation results show that the performance of this algorithm is close to the optimal detector, it has very low complexity, and it works better in comparison to other algorithms.