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Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Department of Electrical and Computer Engineering, | EURASIP Journal on Wireless Communications and Networking 2004 1 1-3 2004 Hindawi Publishing Corporation Editorial Jitendra K. Tugnait Department of Electrical and Computer Engineering Auburn University Auburn AL 36849-S201 USA Email tugnait@eng.auburn.edu Hui Liu Department of Electrical Engineering University of Washington Seattle WA 98195-2500 USA Email hliu@ee.washington.edu Guang Gong Department of Electrical and Computer Engineering University of Waterloo Waterloo Ontario Canada N2L 3G1 Email ggong@calliope.uwaterloo.ca Tongtong Li Department of Electrical and Computer Engineering Michigan State University East Lansing MI 48824-1226 USA Email tongli@egr.msu.edu This editorial reflects the emerging system design and signal detection methods for next-generation digital cellular CDMA system. In CDMA system in addition to intersymbol interference ISI caused by multipath propagation simultaneous transmission also introduces multiuser interference MUI . The receiver is therefore required to separate and recover the information signal of the desired user s . Compared to the conventional single-user detectors where interfering users are modeled as noise significant improvement can be obtained with multiuser detectors where MUI is explicitly part of the signal model. In literature if the spreading sequences are periodic and repeat every information symbol the system is referred to as short-code CDMA and if the spreading sequences are aperiodic or essentially pseudo-random it is known as long-code CDMA. Since multiuser detection relies on the cyclostation-arity of the received signal which is significantly complicated by the time-varying modeling of the long-code system research on blind multiuser detection has largely been limited to short-code CDMA. On the other hand long-code is widely used in virtually all operational and commercially proposed CDMA systems due to its performance stability in frequency fading environment and better information security. More .