Performance variability of linear multiuser detection for DS-CDMA

Abstract

The performance of a linear multiuser detector for direct-sequence (DS) code division multiple access is studied assuming a random signature model and minimum mean squared error (MMSE) detection. Performance criteria considered are near-far resistance (NFR) and signal to interference ratio (SIR). An analytical approximation for the probability density function (PDF) of the NFR is presented, which is accurate when the ratio of users to processing gain is small. The PDF for the SIR is obtained via computer simulation, and our results show that the spread in SIR over the user population can be significant.