Results 261 to 270 of about 2,041,584 (301)
Some of the next articles are maybe not open access.
Perfect periodic correlation sequences
Signal Processing, 1995zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Avraham Freedman +2 more
openaire +1 more source
Perfect DFT sequences transformed into orthogonal sequences
2011 IEEE EUROCON - International Conference on Computer as a Tool, 2011In this paper, we present a method and a code generator to transform perfect DFT (discrete Fourier transform) sequences into orthogonal sequences and into bipolar codes, with good correlation properties. These new sequences or codes produce a low peak-to-average power ratio (PAPR) and a low error probability in a code-division multiple access (CDMA ...
João da Silva Pereira +1 more
openaire +1 more source
A generalized construction for perfect autocorrelation sequences
2015 IEEE International Symposium on Information Theory (ISIT), 2015In this paper we generalize a previous construction in order to design perfect autocorrelation sequences over the so-called PSK+ constellation defined by Boztas, and Udaya [2]. We give a number theoretic criterion for the existence of the new sequences with perfect autocorrelation, and discuss some preliminary numerical results on their aperiodic ...
Serdar Boztas +3 more
openaire +3 more sources
Parameterization of perfect sequences
TENCON 2010 - 2010 IEEE Region 10 Conference, 2010A ZCZ(Zero Correlation Zone) sequence set plays an important role in the research of CDMA, ultrasonic imaging, position control and so on. Its a set of perfect sequences which has a property about cross-correlation. We treat the set of perfect sequences as a zero set of quadratic equations and try to simplify these equations.
Takao Maeda, Takafumi Hayashi
openaire +1 more source
Optimal design of perfect DFT sequences
Physical Communication, 2013Abstract In this paper, we propose a novel scheme to construct a large set with N ( N + 1 ) perfect sequences of length N , derived from an Inverse Discrete Fourier Transform (IDFT) of Chu and maximum-length sequences. This optimum set of perfect periodic autocorrelation sequences has a maximum absolute value of periodic cross ...
Pereira, João S. +1 more
openaire +3 more sources
Almost-perfect quadriphase sequences
IEEE Transactions on Information Theory, 2001Summary: A new class of quadriphase sequences of length \(N=p^J+1\equiv 2\bmod 4\) (\(p\) odd prime, \(J=1,2,\dots\)) is presented. These almost perfect sequences have a periodic autocorrelation function \(\Theta(\tau)\) that vanishes for all \(\tau\not\equiv 0\bmod(N/2)\).
openaire +1 more source
Almost perfect autocorrelation sequences
IEEE Transactions on Information Theory, 1992Almost perfect autocorrelation sequences are defined as complex periodic sequences such that all the out-of-phase autocorrelation coefficients are zero except one. The study is restricted to (-1,+1)-sequences. In this case, such sequences exist only if the period n is a multiple of 4.
openaire +1 more source
Almost-Perfect and Odd-Perfect Ternary Sequences
2005Ternary (–1, 0, +1) almost-perfect and odd-perfect autocorrelation sequences are applied in many communication, radar and sonar systems, where signals with good periodic autocorrelation are required. New families of almost-perfect ternary (APT) sequences of length N = (pn – 1)/r, where r is an integer, and odd-perfect ternary (OPT) sequences of length ...
openaire +2 more sources
De Bruijn Sequences and Perfect Factors
SIAM Journal on Discrete Mathematics, 1997Summary: We describe new constructions for de Bruijn sequences and perfect factors. These constructions are all based upon the idea of constructing one sequence (or set of sequences) from another. As a result of this fact, the sequences obtained from these construction methods possess simple decoding algorithms based on decoding the sequences used to ...
openaire +10 more sources
Binary Almost-Perfect Sequence Sets
IEEE Transactions on Information Theory, 2010Sequence set with lower correlation values is highly desired for engineering applications. However, theoretical results (e.g., Welch bound) show that θmax ≥ √(N) in general, that is, the maximum out-of-phase autocorrelation and cross-correlation magnitudes of a sequence set is not less than the square root of the sequence period.
Kai Cai, Guobiao Weng, Xueqi Cheng
exaly +2 more sources