Chip-Level Adaptive Equalization for LAS CDMA Downlink

This paper deals with the chip-level equalization technique for large area synchronized-code division multiple access (LAS CDMA) system communications. In the downlink of LAS CDMA, frequency-selective multi-path channel often destroys the orthogonality of spread codes at receivers between users and introduces inter-path interference (IPI), inter-symbol interference (ISI) and multi-path access interference (MAI). The conventional RAKE receiver is limited in suppressing IPI and MAI. Chip equalization is an efficient tool to restore the orthogonality of the user signals. So we focus on a new chip equalization scheme of receiver based on three criterions, and proposed the adaptive implementation algorithms. Simulation results show improved performance as compared with the RAKE receiver for the CDMA downlink.