Premium
Modified Walsh‐Hadamard sequences for DS CDMA wireless systems
Author(s) -
Wysocki B. J.,
Wysocki T. A.
Publication year - 2002
Publication title -
international journal of adaptive control and signal processing
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.73
H-Index - 66
eISSN - 1099-1115
pISSN - 0890-6327
DOI - 10.1002/acs.727
Subject(s) - hadamard transform , aperiodic graph , orthogonality , complementary sequences , polyphase system , autocorrelation , algorithm , code division multiple access , mathematics , walsh function , hadamard matrix , asynchronous communication , sequence (biology) , hadamard code , synchronization (alternating current) , computer science , electronic engineering , topology (electrical circuits) , discrete mathematics , telecommunications , statistics , combinatorics , engineering , mathematical analysis , geometry , biology , genetics
We propose a simple but efficient method for modifying Walsh–Hadamard sequences to achieve correlation properties suited for asynchronous DS CDMA applications. The proposed method can be used to minimize the mean square value of aperiodic cross‐correlation or the mean square value of aperiodic autocorrelation, the maximum value of aperiodic cross‐correlation functions, merit factor or other properties of the sequence set. The important feature of the method is that it modifies correlation properties of the sequence set, while preserving their orthogonality for the perfect synchronization. The proposed method can be applied to obtain bipolar, quadri‐phase, or general polyphase sequences. Copyright © 2002 John Wiley & Sons, Ltd.