TY  - JOUR
T1  - Binary Sequences of Even Period with 5-Level Autocorrelation and Their Variations for Optimum Odd Autocorrelation
AU  - Kim, Gangsan 
AU  - Song, Hong-Yeop 
JO  - The Journal of Korean Institute of Communications and Information Sciences
PY  - 2025
DA  - 2025/1/1
DO  - 10.7840/kics.2025.50.8.1207
KW  - Binary sequences
KW  - Cyclic relative difference sets
KW  - Favourable autocorrelation
AB  - In this paper, we propose a balanced binary sequence of period 2u for some even values of u with 5-level autocorrelation from a cyclic relative difference set with parameters (u,2,u-1,u/2-1). Furthermore, we identify its half-period as those having an optimum odd autocorrelation, and we found that changing one specific bit of this binary sequence results in an almost perfect sequence. Various relations of these with some previous constructions by others are discussed.