1,528 research outputs found
New Optimal Binary Sequences with Period via Interleaving Ding-Helleseth-Lam Sequences
Binary sequences with optimal autocorrelation play important roles in radar,
communication, and cryptography. Finding new binary sequences with optimal
autocorrelation has been an interesting research topic in sequence design.
Ding-Helleseth-Lam sequences are such a class of binary sequences of period
, where is an odd prime with . The objective of this
letter is to present a construction of binary sequences of period via
interleaving four suitable Ding-Helleseth-Lam sequences. This construction
generates new binary sequences with optimal autocorrelation which can not be
produced by earlier ones
Cross Z-Complementary Pairs for Optimal Training in Spatial Modulation Over Frequency Selective Channels
The contributions of this article are twofold: Firstly, we introduce a novel class of sequence pairs, called “cross Z-complementary pairs (CZCPs),” each displaying zero-correlation zone (ZCZ) properties for both their aperiodic autocorrelation sums and crosscorrelation sums. Systematic constructions of perfect CZCPs based on selected Golay complementary pairs (GCPs) are presented. Secondly, we point out that CZCPs can be utilized as a key component in designing training sequences for broadband spatial modulation (SM) systems. We show that our proposed SM training sequences derived from CZCPs lead to optimal channel estimation performance over frequency-selective channels
A survey on modular Hadamard matrices
AbstractWe provide constructions of 32-modular Hadamard matrices for every size n divisible by 4. They are based on the description of several families of modular Golay pairs and quadruples. Higher moduli are also considered, such as 48,64,128 and 192. Finally, we exhibit infinite families of circulant modular Hadamard matrices of various types for suitable moduli and sizes
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