Subspace-based multiuser detection for antenna array CDMA systems

Abstract

In this paper, an adaptive multiuser detector based on signal subspace estimation is proposed for synchronous CDMA systems with an antenna array. Based on a training sequence transmitted by the desired user, we obtain a linear MMSE detector which does not require knowledge of the code sequences and the channel impulse response. The proposed spatial-temporal adaptive multiuser detection technique is shown to be robust against the near-far problem and computationally efficient by using subspace tracking algorithm.