Matched filters with interference suppression capabilities for DS-CDMA

This paper considers the design of near-far resistant matched filters (MFs) for direct-sequence code-division multiaccess (DS-CDMA) systems. We show how additional information on the individual powers and chip delays of locked users, that is available at the base station, can be exploited for the design of these MFs. The proposed receiver can specifically reduce the effects of the locked interferers at the expense of a partial increase in complexity over the conventional MF. Furthermore, this detection technique is a link between the linear minimum mean squared error (MMSE) centralized multiuser detector and the decentralized noise-whitening MF. Numerical results for the rectangular chip pulse illustrate the signal-to-noise ratio (SNR), near-far resistance, and bit-error rate (BER) improvement that the proposed MF yields over the conventional MF and noise-whitening MF.