Uplink multiuser detection for CDMA systems based on layered space-time coding
Yiwen Zhang · Systems engineering and electronics · 2004
Most proposed space-time codec schemes focus on the single-user scenario, which can not be applied in the mobile communication systems directly. Therefore a multi-user multi-input multi-output (MIMO) system in the frequency-selective fading environment is studied. A direct sequence code-division multiple-access (DS-CDMA) scheme using vertical Bell Labs layered space-time (V-BLAST) structure at the user side is proposed. With the assistance of the rotational invariant of the transmitted symbols and the singular value decomposition (SVD), an uplink spatial-temporal multiuser detector is derived based on the blind estimation of the vector channel impulse response (VCIR). This novel scheme has the potential of providing the anticipated multiuser detection (MUD) performance gains with a manageable complexity for the V-BLAST coded CDMA system with the arbitrary antennas. Computer simulation results demonstrate the validity of this proposed scheme.