Blind channel estimation and data recovery in DS spread spectrum systems

Recently, a new approach to the problem of data detection for communication s over band-limited channels with unknown channel-impulse response is propo sed (Vaidis and Weber, IEEE Trans. Commun. 46 (February 1998) 232). This ap proach utilizes the Viterbi algorithm (VA) for maximum-likelihood sequence estimation (MLSE) in a block adaptive technique for simultaneous channel an d data estimation. In this paper, a novel computationally efficient modifie d VA is developed for MLSE in direct sequence (DS) spread spectrum system. The new modified VA is employed in the approach of Vaidis and Weber (1998) for recovering DS spread spectrum signals in the presence of channel distor tion and additive Gaussian noise. The simulation results show that the appr oach of Vaidis and Weber (1998) implemented with the new modified VA achiev es lower probability of error and higher speed of convergence. (C) 2001 Els evier Science B.V. All rights reserved.