Combating Near Far Effects of Linear MMSE Multiuser Detection in Coded OFDM-CDMA

Abstract

This paper deals with near far effects encountered in MMSE linear multiuser detection and proposes a method to mitigate the transmit-power dependent userspecific bit error rates by introducing an additional postprocessing by a combination of nonlinear parallel and successive interference cancellation. Throughout the paper we consider a quasisynchronous (i.e. asynchronous with coarse synchronization at the receiver) OFDM-CDMA uplink transmission as well as perfectly known channel impulse responses.