摘要
采用信道编码技术能提高跳频系统的抗干扰能力,而精确的信道状态信息有利于提高系统误码率性能。基于和积译码过程,提出一种新的迭代信道估计译码算法,把译码后验信息反馈给信道节点并重新计算信道状态概率,生成新的对数似然比作为下一次迭代的先验消息,而且信道估计与编码信息在迭代中交替更新。仿真结果表明在部分频带干扰的LDPC编码慢跳频系统中,该算法性能优于传统的门限检测法,而且每个跳频时隙只需要较少符号就能够接近有精确信道状态信息的情况。
Channel coding techniques can improve the anti-jamming capabilities of frequency-hopping systems,and the ac-curate channel state information is helpful for the error-bits rate of system. Based on the sum-product decoding process,a novel iterative decoding algorithm with channel estimation is proposed,in which the posteriori information of decoding result is fed back to the channel nodes,and then the probability of channel state is calculated again to generate the new log-likelihood ratios as the prior message of the next iteration. The channel estimation and coding information are updated by turns in those iterations. The simulation results show that,in the low density parity check (LDPC) coding slow frequency-hopping system with partial-band noise jamming,the proposed algorithm outperforms the traditional threshold-test algorithms,and only a few symbols in each frequency-hopping time slot are required to obtain the system performance similar to the case with perfect channel state in-formation.
出处
《现代电子技术》
2014年第19期18-20,24,共4页
Modern Electronics Technique
关键词
跳频
LDPC码
部分频带干扰
和积译码
迭代信道估计
frequency-hopping
low density parity check coding
partial-band noise jamming
sum-product decoding
channel estimation with iteration
