Title :
Optimal signature sequences for asynchronous CDMA systems with fixed signal delays
Author :
Stanczak, Stawomir ; Boche, Holger
Author_Institution :
Heinrich-Hertz-Inst. fur Nachrichtentech. Berlin GmbH, Germany
Abstract :
The paper addresses the problem of designing signature sequences for asynchronous CDMA channels with fixed signal delays. Assuming that users may be received at different power levels, the paper characterizes the so-called aperiodic WBE (A-WBE) sequences that are shown to maximize signal-to-interference ratios of the users. Using a compact matrix notation, we provide necessary and sufficient conditions for sequences to form a A-WBE sequence set and prove some important properties such sequence sets have. In some special cases, a method for constructing A-WBE sequences is presented.
Keywords :
code division multiple access; delays; filtering theory; matched filters; multiuser channels; optimisation; sequences; set theory; signal synthesis; A-WBE sequence set; Welch-bound-equality; aperiodic WBE sequences; asynchronous CDMA channels; asynchronous CDMA systems; compact matrix notation; matched filters; necessary conditions; optimal signature sequences; power levels; signal delays; signal-to-interference ratios; signature sequence design; sufficient conditions; Delay; H infinity control; Interference; Iterative algorithms; Matched filters; Multiaccess communication; Performance gain; Power system modeling; Signal design; Sufficient conditions;
Conference_Titel :
Wireless Personal Multimedia Communications, 2002. The 5th International Symposium on
Print_ISBN :
0-7803-7442-8
DOI :
10.1109/WPMC.2002.1088358
