Interference subspace rejection: A framework for multiuser detection in wideband CDMA

We present a unifying framework for a new class of receivers that employ linearly-constrained interference cancellation (IC). The associated multiuser detectors operate in various modes and options ranging in performance from that of IC detectors to that of linear receivers, yet provide more attractive performance/complexity tradeoffs. They exploit both space and time diversities as well as the array-processing capabilities of multiple antennas and carry out simultaneous channel and timing estimation, signal combining and interference rejection. Additionally, they can operate on both links and in multiple mixed-rate traffic scenarios. The improved performance can be translated to increased utilization of wideband code division multiple access networks, particularly at high data rates.