Performance Comparison of Concatenated Codes with Repetitive Code in Slow Frequency Hopping Communication.

Frequency hopping (FH) is a widely employed communication technique for countering jamming. However, the robustness can significantly degrade when jamming signals align with the hopping frequencies. To address this issue, channel coding is employed as an effective solution. This study focuses on the optimization of concatenated codes for a slow FH system that experiences a high probability of jamming. Additionally, a more universal jamming model is proposed. The performance of concatenated codes employing tail-biting Turbo code, Polar code, and LDPC code as the outer code, combined with repetitive code as the inner code, is meticulously evaluated. Numerical results demonstrate that both tail-biting Turbo code-repetitive code and Polar code-repetitive code achieve reliable transmission, even under an 80% probability of jamming. Notably, reducing the code rate of the repetitive code, rather than the outer code rate, proves to be an effective approach for enhancing the system's resilience to jamming while reducing decoding complexity.