On blind channel identification for DS/CDMA communications
Urbashi Mitra · 1998
Blind channel identification techniques based on second order statistics are investigated for multi-user systems employing Direct-Sequence/Code-Division MultipleAccess (DS/CDMA). The methods exploit knowledge of the spreading code of the user of interest via matched filtering, as well as properties of spreading codes. Two schemes are presented: one for deterministic short sequence DS/CDMA and a method appropriate for randomized long sequence DS/CDMA. The matched filter based techniques offer reduced complexity vis 'a vis methods which operate on the received signal directly. In fact, it can be shown that as the number of matched filters increases, the proposed technique approaches a previously proposed method. 1 INTRODUCTION In this work, we explore blind channel identification schemes for multi-user systems employing DirectSequence /Code-Division Multiple-Access (DS/CDMA) based on second order statistics. The search for blind identification methods is motivated by the need for equal...