Joint multiuser detection of CD and AFSA in DS-UWB communication systems

This study mainly studies the application of Multiuser Detection (MUD) technology in DS-UWB multiple-access communication systems. As the time complexity of Optimum Multiuser Detection (OMUD) ascends quickly when the number of users increases and the BER performance of Correlation Detection (CD) is very poor, we proposed a Joint Multiuser Detection Algorithm of CD and AFSA (CD-AFSA-MUD). The process of OMUD is similar with that of the function's optimization, meanwhile Artificial Fish Swarm Algorithm (AFSA) is good at optimization because it can realize the global convergence. In order to accelerate the speed of global convergence and reduce the number of iteration for AFSA, we use the sub-optimal result of CD and its modified formations as the initial values of Artificial Fishes (AFs), which is a hybrid multiuser detection method. That is, we apply the sub-optimal value to approximate the optimal value. Computer simulation experiments show that the BER performance of CD-AFSA-MUD is much better than those of CD and AFSA-MUD which is also close to that of OMUD; furthermore, its convergence rate and the ability to resist Near-far Effect are superior to those of other MUD algorithms.