融入ldpc纠错机制的认知无线电物理层认证分析-计算机科学.pdfVIP

Vo1. 44 No. 7 第 44 卷第7 期 计算机科学 2017 年 7 月 COMPUTER SCIENCE July 2017 融入 LDPC 纠错机制的认知无线电物理层认证分析 周雪倩吴晓富余训健 (南京邮电大学通信与信息工程学院 南京 210003) 摘 要 从信道纠错编码的角度来探讨认知无线电寄生认证信适的容量。首先，通过推导认证信适的对数似然比，给 出了其简化计算方式，分析与仿真结采表明:简化计算与严格计算结采相仿，因而认证信适可等效为二元输入的加性 高斯白嗓声(BI-AWGN)信道。其次，基于对数似然比的简化形式，通过置信度传播迭代译码，考察了融入 LDPC 纠错 机制的认证信道实际传输性能，仿真结采表明:实际简化译码的结果与理想 BI-AWGN 的译码性能无法区分。最终得 出研究结论:认知无线电寄生认证信道可严格等效为 BI-AWGN 1言道，因而可采用 BI-AWGN 信道设计的纠错编码来 有效逗近寄生认证信适的传输极限。 关键词 认知元线电，寄生认证信道，对数似然比，二元输入加性白噪声信道，纠错编码 中固法分类号 TN918 文献标识码 A 四)1 10. 11896/j. issn. 1002-137)♀ 2017.07.016 LDPC Coded Primary Transmitter Åuthentication Schemes in Cognitive Radio Networks ZHOU Xue-qian WU Xiao-fu YU Xun-jian (College of Telecommunication Inforrnation Engineering ,Nanjing University of Posts and Telecommunication ,Nanjing 210003 ,China) Abstract In this paper ,the capacity of embedded primary transmitter authentication channel in cognitive radio is inves- tigated. By employing the log-likelihood ratios(LLRs) of a tag bit and its approximation ,we showed that the equivalent authentication channel observed by the secondary receiver can be viewed as a binary-input additive white Gaussian noise (BI-AWGN) channel. Then ,we investigated the practical performance of the embedded authentication channel with the use of LDPC coding. With the approximate form of LLRs ,we found that it performs very close to that of belief propaga tion decoding over the ideal BI-AWGN channel. Hence ,we concluded that a good error-control coding scheme for a BI- AWGN channel is also good for embedded primary transmitter authentication channel ,and the proposed approximate form of LLRs can be well exploited to faci