Robust CDMA signal detection in the presence of user and interference signature mismatch

Abstract

Signal detection in multiuser CDMA systems is particularly attractive when the desired user signature and some interferer signatures are known and are not completely orthogonal at the receiver. As many multiuser systems must deal with the near-far problem, a weakness common to several known blind multiuser CDMA detectors is that the detection performance is very sensitive to signature waveform mismatch (SWM) which occurs a result of channel distortion. We consider the design of a partially blind multiuser CDMA detector that is robust to the SWM. We present a convex formulation of this problem by using second-order cone programming (SOCP). The resulting SOCP can be solved efficiently using the recently developed interior point methods. Computer simulations indicate that the performance of our new robust multiuser detector is superior to the one that does not utilize the interference information.