Adaptive subspace-based multiuser detectors for base station

An adaptive multiuser detection scheme based on signal subspace spanned by the signature waveforms of the desired user and the interfering users is proposed for the inverse link of mobile cellular DS-CDMA communication systems. This multiuser detection scheme is implemented without the need to estimate the signal subspace since the signal subspace spanned by the user's signature waveforms can be fully made use of. A new joint space-time multiuser detector with antenna arrays is also presented by the extension of the temporal multiuser detection scheme. An adaptive implementation on the basis of recursive inversion of an autocorrelation matrix is developed. The presented multiuser detectors offer better performance, robustness, and lower computational complexity against the hostile signal-to-noise interference ratio environment. The simulation results are provided to verify the theory analysis.