Delay Estimation in Long-Code Asynchronous DS/CDMA Systems Using Multiple Antennas

摘要

This paper addresses the problem of propagation delay estimation in asynchronous long-code DS/CDMA multi-user systems. Almost all the methods proposed so far in the literature for propagation delay estimation are derived for short codes and the knowledge of the codes is exploited by the estimators. In long-code CDMA, the spreading code is aperiodic and the methods developed for short codes may not be used or may increase the complexity significantly. For example, in the subspace based estimators, the aperiodic nature of the code may require subspace tracking. We propose a method for joint channel and delay estimation in uplink DS/CDMA using multiple antennas.