TY  - JOUR
T1  - Encoding-Rule-Candidate Group Design for Security Rate Enhancement of Space-Time Line Code Hopping Systems
AU  - Choi, Taehee 
AU  - Kim, Jaehong 
AU  - Joung, Jingon 
JO  - The Journal of Korean Institute of Communications and Information Sciences
PY  - 2025
DA  - 2025/1/1
DO  - 10.7840/kics.2025.50.7.1058
KW  - Space-time line code (STLC)
KW  - code hopping
KW  - secure communications
AB  - In conventional space-time line code (STLC) systems with eavesdroppers (Eve), the security performance is significantly degraded when the user and Eve channels are highly correlated. An STLC hopping scheme was recently proposed to overcome this limitation, where an encoding rule is randomly selected from a candidate group for every two symbols, resulting in decoding failure for Eve. Here, the optimal encoding rule candidate group can be designed by selecting rules that achieve high secrecy rates, and the optimal candidate group is dependent on the channel correlation factor. In this study, we propose two design methods, depending on whether the transmitter knows the channel correlation factor. Simulation results show that the proposed scheme achieves optimal performance if the correlation information is provided. When the correlation factor is unknown to the transmitter, the STLC hopping scheme with the proposed method achieves a secrecy rate of over 95.5% of the maximum secrecy rate achieved by an optimal STLC hopping scheme.