QC-LDPC码在混沌DSSS-NBJ抑制中的性能分析  

Performance analysis of QC-LDPC Codes in the chaotic DSSS for NBJ suppression

作　　者：李思佳[1] 毛玉泉[1] 李波[1] 裴鑫[1] 吴崇虎[1] 

机构地区：[1]空军工程大学信息与导航学院,陕西西安710077

出　　处：《电路与系统学报》2013年第1期76-83,共8页Journal of Circuits and Systems

基　　金：国家863计划创新基金(2010AAJ145);国家自然科学基金(60972042);陕西省电子信息系统综合集成重点实验室基金(201102Y05);空军工程大学研究生创新课题(20110301);空军工程大学电讯工程学院科研创新基金资助(DYCX1040)

摘　　要：以低信噪比窄带干扰条件下混沌DSSS系统信息传输的可靠性提高为目的,在混沌DSSS系统的基础上,结合QC-LDPC码提出了一种基于QC-LDPC-CDSSS的协同窄带干扰(Narrowband Jamming,NBJ)抑制方案。该方案在直积构造方法生成校验矩阵的过程中,完成了校验矩阵4、6短环的检验与消除,采用近似下三角算法实现了QC-LDPC编码;对于混沌直序扩频系统,分析了组合混沌映射序列的性能和优选方法,采用优选的组合混沌扩频序列增强低截获能力;最后通过不同干扰条件下的仿真验证了该方案的有效性,仿真结果表明,该方案对于单音干扰的抑制效果优于多音干扰的抑制效果,在10-5的误码要求条件下,信噪比小于4dB。In order to improve the bit-error-rate（BER） at the low SNR,a novel cooperative anti-jamming scheme for narrow-band jamming suppression is proposed based on the QC-LDPC codes and integrated Map chaotic direct sequence spread spectrum.The QC-LDPC codes are designed through approximate lower triangular form algorithm based on the parity check matrix.The direct product is used for constructing the parity check matrix.The performance of chaotic spread spectrum sequences,produced from the integrated Chaotic MAP,is analyzed and their optimized selection algorithm is proposed.Finally,the strategy is verified through simulations with different jamming.The results show that the scheme performs better with single tone jamming than multi-tone jamming and the SNR is smaller than 4dB when the BER is 10^-5.

关 键 词：QC—LDPC 组合混沌映射 校验矩阵 直接序列扩频 干扰抑制 

分 类 号：TN911.22[电子电信—通信与信息系统] TN911.42[电子电信—信息与通信工程]