A low-complexity multiuser detection method based on mean field annealing

Multiuser detection is an important technique used to suppress multiple access interference (MAI) in CDMA system. A novel reduced-order multistage PIC multiuser detection method based on mean field annealing in an asynchronous multipath CDMA system is presented in this paper to solve the problem that the conventional optimal multiuser detection methods have the characteristics of larger calculation and slower convergence. This method employs mean field annealing technique, and then the NP-complete problem of minimizing the objective function of the optimal multiuser detection can be translated into minimizing a mean field annealing network energy function. This method uses the block Toeplitz characteristics of matrix, and then larger matrix can be replaced by small matrix, which leads to reduced order and calculation effectively. Theory and experimental results reveal that this method has the better performance to cancel MAI, suppress inter-symbol interference and multipath fading, and this method has small calculation so it can be implemented in real-time. Finally the reduced-order multistage PIC multiuser detection method based on mean field annealing given in this paper is a better scheme for asynchronous multipath CDMA systems.