Design of Modified UCHT Sequences

Document type: Conference Papers
Peer reviewed: Yes
Author(s): Gregory Cresp, Hai Huyen Dam, Hans-Jürgen Zepernick
Title: Design of Modified UCHT Sequences
Conference name: IEEE Symposium on Trends in Communications
Year: 2006
Pagination: 40-43
Publisher: IEEE
City: Bratislava
Organization: Blekinge Institute of Technology
Department: School of Engineering - Dept. of Signal Processing (Sektionen för teknik – avd. för signalbehandling)
School of Engineering S- 372 25 Ronneby
+46 455 38 50 00
Authors e-mail:,,
Language: English
Abstract: In this paper, we consider the design of a class of unified
complex Hadamard transform (UCHT) sequences. An effi-
cient modification is imposed to those sequences to better
suit applications in asynchronous code-division multiple-
access (CDMA) systems. These modified UCHT sequences
preserve the orthogonality of the original UCHT sequences
and offer increased design options due to an increased
number of parameters. The design of UCHT, modified
UCHT, and Oppermann sequences is then formulated with
reference to optimizing the maximum nontrivial aperiodic
correlation value. These optimization problems can then
be solved efficiently using a genetic algorithm with the
maximum nontrivial aperiodic correlation value serving in
the definition of a fitness function. Numerical examples
illustrate the benefits of modified UCHT sequences over the
original UCHT sequences.
Subject: Telecommunications\General