窄带信道中基于接收信号相位的密钥容量研究

摘要

Wireless channel is of reciprocity, temporal variability and spatial variability. The legitimate users can generate secret key based on the property of the wireless channel. This paper proposes a calculation method for the capacity of the secret key. It establishes a reasonable wiretap channel model based on source of correlated randomness in the narrowband channel. The secret key capacity based on the phase of the received signal is deduced and the corresponding analytical expressions is obtained utilizing information theory and random signal processing theory on the basis of established channel model. The simulation results demonstrate that the secret key capacity is increased with the reciprocal extent of the channels between legitimate users and the SNR of received signals and the secret key capacity based on the phase information is smaller than the capacity based on received signals. Therefore, the legitimate users can apply the joint information distillation of envelope and phase in received signals to get more secret key bits.%无线信道具有互易性、时变性和空变性等特点，合法双方可以利用无线信道的特性生成共享密钥。基于此，提出一种密钥容量的求解方法。对窄带信道中基于相关随机源模型的窃听信道进行合理建模，利用信息论及随机信号分析理论，对基于接收信号相位信息的密钥容量进行推导，得到密钥容量的表达式。仿真结果表明，密钥容量随信噪比与合法双方信道相关系数的增大而增大，且基于接收信号相位的密钥容量小于基于接收信号的密钥容量，因此，合法双方为得到更长的密钥，可以进行接收信号包络、相位信息的联合提取。