Blind parameter estimation in multiple-access systems

A blind algorithm for the estimation of amplitude, phase, and relative time delay of each user in multiple-access communication systems is proposed. This algorithm is based on the cyclostationarity features of the received signals and provides estimates of the unknown parameters that are intrinsically immune to the effects of noise and interference, provided that a cycle frequency of the user signals exists which is not shared with the disturbance terms. The proposed estimators are, under mild assumptions, asymptotically unbiased and consistent, Moreover, the proposed algorithm is asymptotically near-far resistant and is not based on the usual assumption of white and/or Gaussian noise