In this paper, an adaptive multiuser receiver for variable spreading length direct-sequence code- division multiple-access systems in multi-path channel is proposed. The signature vectors are estimated by projection onto the intersectant subspaces. Based on the estimated signature vectors, the multiuser detector is constructed. By exploiting the structure of the subspace tracking algorithm, the low-complexity adaptive signature vectors estimator and multiuser receiver are developed. Simulation results demonstrate that the proposed algorithm has the same performance,but lower computational complexity compared with the reference algorithm.
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