Özet:

Code selection has a large impact on the performance of a direct sequence-code division multiple access (DS-CDMA) system. A goal of spread spectrum system designers for a multiple access system is to find a set of such spreading codes that as many users as possible can use a band of frequencies with as little multiple access interference (MAI) as possible. If the number of active users in a DS-CDMA system using exponentially weighted despreading sequences is less than the number of codes in a given code set, it is very important in terms of the quality of the recovered information to determine the codes which will yield the best bit error rate (BER) performances. In this study, it is proposed that, a simple and efficient criterion which enables the determination of the spreading sequences in a given code set achieves better BER performances than others when used as references for a DS-CDMA system which employs exponentially weighted despreading sequences

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