Blind separation of convolved mixtures for CDMA systems
Răzvan Cristescu, Tapani Ristaniemi, J. Joutsensalo, Juha Karhunen · 2000
This paper presents a new method for symbol estimation in the downlink of a CDMA communication system. Our approach is based on the observation that the slowly-fading CDMA signal model may be expressed as a linear combination of the convolved independent symbol sequences. A blind source separation approach based on maximization of output entropy is used for the blind separation of the sources; the symbols corresponding to the user of interest are determined using a small training sequence. Our method shows good simulation results when compared to traditional symbol separation techniques. 1 INTRODUCTION Code Division Multiple Access (CDMA) is a data transmission technique for the third generation of mobile phones, based on spread spectrum methods. The CDMA system enables users to transmit over the same frequency band simultaneously. The identication of a particular user is done by his unique code. In the uplink (e.g. base station) signal processing the codes of the users are known b...