Multiuser detection algorithm for space-time CDMA-systems

In the multiuser detection (MUD) techniques, one of the most difficult problems is how to reduce the computational complexity and then improve the performance of the system. In this paper, based on the space-time CDMA system, we apply the method of the steepest descent with the noisy gradient to the multiuser detection of the system. In the multiuser detection algorithm, we change the conventional fixed step-size iterations into the time-varying step-size iterations with the noisy gradient. Simulations show that the algorithm of the multiuser detection can converge rapidly and guarantee that space-time CDMA system gets the better performance at the same time.