Neural networks for multiuser detector in asynchronous PC/SS communication system

Proposes a neural network for a multiuser detector in a parallel combinatory/spread spectrum (PC/SS) multiple access communication system. In the PC/SS system, M orthogonal sequences are assigned for one user, and q out of M (q⩽M) sequences are used for transmitting information. The combination of sequences can transmit more information than the conventional CDMA systems. In general, all of the users´ signals overlap in time and frequency and cause mutual interference. Multiuser detection is a vital technique for combating mutual interference and near-far problems. The paper proposes a neural system for the multiuser detector in the PC/SS, which can output three values, +1, -1 and 0. It is compared with the conventional detector, and its performance evaluated