Limited linear cancellation of multiuser interference in DS/CDMA asynchronous systems

This paper presents a linear cancellation detector for the Gaussian channel, operating over limited time intervals of the received signal, in a similar way to a multiinput multioutput finite-impulse response (FIR) filter. The parameters defining the detector become time invariant, and the conditions to be met by the signatures are stated. A bound for the multiuser interference due to the limited time correlation, and upper and lower bounds for the error probability are obtained. The theoretical bounds and numerical results show that the detector is adequate for systems intended for many users whose amplitudes can be restricted to a given range.