基于MAP准则的无线信道密钥量化算法  

Wireless Channel Key Quantization Algorithm Based on MAP

作　　者：田克明 辛刚 郭东琴 张剑[1] TIAN Keming;XIN Gang;GUO Dongqin;ZHANG Jian(Information Engineering University,Zhengzhou 450001,China)

机构地区：[1]信息工程大学,河南郑州450001

出　　处：《信息工程大学学报》2024年第1期17-23,共7页Journal of Information Engineering University

基　　金：国家自然科学基金资助项目(62271505);国家重大研发计划资助项目(2022YFB28022804)。

摘　　要：在物理层安全领域中,基于无线信道的密钥生成技术包括信道探测、量化、密钥协商和保密增强等4个步骤。针对传统量化方案仅关注量化端点值设计、初始密钥不一致率(Key Disagreement Rate,KDR)偏高的问题,通过搭建对合作方量化结果进行概率推算的数学模型,获取其量化符号信息和比特软信息,提出了基于最大后验判决准则(Maximum a Posteriori,MAP)的量化算法。仿真结果表明,所提算法能取得更低的KDR,在信噪比为10 dB环境下,该算法的KDR比等概量化降低了43%,比信道交互量化(Channel Quantization Alternating,CQA)降低了35%;采用2比特量化,该算法的可生成密钥长度较CQA提高了2倍。In the field of physical layer security,key generation technology based on wireless channel includes four steps:channel detection,quantization,key reconciliation and security enhancement.Considering the traditional quantization schemes only focus on the design of quantization terminal value and the high initial key disagreement rate(KDR),a quantization algorithm based on maximum a posteriori decision criterion(MAP)is proposed by constructing a mathematical model to calculate the probability of the partner’s quantization results,and obtaining its quantized symbol information and bit soft-information.The simulation results show that the proposed algorithm can achieve lower KDR.The KDR of the proposed algorithm is 43%and 35%lower than that of equal probability quantization and channel quantization alternating(CQA)algorithm respectively when SNR is 10 dB.Meanwhile,adopting 2-bits quantization,the length of the generated key of the algorithm is two times longer than that of CQA.

关 键 词：密钥生成技术 密钥不一致率 量化门限 最大后验判决准则 密钥长度 

分 类 号：TN918[电子电信—通信与信息系统]