现代电子技术
現代電子技術
현대전자기술
MODERN ELECTRONICS TECHNIQUE
2014年
19期
18-20,24
,共4页
跳频%LDPC码%部分频带干扰%和积译码%迭代信道估计
跳頻%LDPC碼%部分頻帶榦擾%和積譯碼%迭代信道估計
도빈%LDPC마%부분빈대간우%화적역마%질대신도고계
frequency-hopping%low density parity check coding%partial-band noise jamming%sum-product decoding%chan-nel estimation with iteration
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。
採用信道編碼技術能提高跳頻繫統的抗榦擾能力，而精確的信道狀態信息有利于提高繫統誤碼率性能。基于和積譯碼過程，提齣一種新的迭代信道估計譯碼算法，把譯碼後驗信息反饋給信道節點併重新計算信道狀態概率，生成新的對數似然比作為下一次迭代的先驗消息，而且信道估計與編碼信息在迭代中交替更新。倣真結果錶明在部分頻帶榦擾的LDPC編碼慢跳頻繫統中，該算法性能優于傳統的門限檢測法，而且每箇跳頻時隙隻需要較少符號就能夠接近有精確信道狀態信息的情況。
채용신도편마기술능제고도빈계통적항간우능력，이정학적신도상태신식유리우제고계통오마솔성능。기우화적역마과정，제출일충신적질대신도고계역마산법，파역마후험신식반궤급신도절점병중신계산신도상태개솔，생성신적대수사연비작위하일차질대적선험소식，이차신도고계여편마신식재질대중교체경신。방진결과표명재부분빈대간우적LDPC편마만도빈계통중，해산법성능우우전통적문한검측법，이차매개도빈시극지수요교소부호취능구접근유정학신도상태신식적정황。
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.
