A subspace scheme for blind user identification in multiuser DS-CDMA

A subspace approach for user identification in a synchronous multiuser code division multiplex access (CDMA) is suggested. In this scheme, prior knowledge of the spreading codes and user powers is not required. The spreading codes and the corresponding received amplitudes are both estimated are both estimated from the received signal, and are used to identify the active users. Eigenvalue decomposition (EVD) is performed on the received signal and through a recursive algorithm, the spreading codes and the received powers are estimated. Simulation results indicate that the approach is capable of identifying the active users and their related powers without relying on any prior information.