Analysis of LDPC code in the FH system with partial‐band interference
Jingke Dai, Yaque Jing, Minli Yao · IET Communications · 2017
The performance of low‐density parity‐check (LDPC) code is analysed in the frequency hopping (FH) system with partial‐band interference (PBI). Both of Slow Frequency hopping (SFH)/binary phase‐shift keying (SK) and Fast Frequency hopping (FFH)/binary frequency‐SK schemes are considered in which the channel fading and diversity combining are involved, respectively. The symmetry conditions on PBI channel are proven, and then the probability densities of initial message for sum–product decoder are derived. Given a probability of hopping to a jammed state, the decoding thresholds of LDPC codes on PBI channel are obtained using density evolution, which are in good agreement with the simulation results. Furthermore, the irregular LDPC codes are optimised over PBI channel, and the simulation result shows that it has better anti‐jamming performance than the existing regular and irregular codes which have been employed in FH systems.