在传播环境不发生改变时，唯一能带来不确定性的因素是用户位置的不断变化。该文研究了用户位置移动范围与无线密钥生成速率上界的关系。针对两种极端的静态环境场景，分析了其密钥生成速率上界。结果表明：在简单的信道环境中，信道状态分布并不是Gauss分布，此时的密钥生成速率上界仅受到用户位置改变的影响。该文分析了在简单的单反射面场景下密钥生成速率上界与信道的估计误差之间的关系。通过数值仿真得到了多散射点场景下不同信道估计误差下的密钥生成速率上界，结果表明在合法用户具有较高信噪比情况下，用户位置移动范围在1个波长左右即可获得较高的密钥生成速率上界。
When the propagation environment does not change, the only factor that can lead to uncertainties in the key generation rate is the changing position of the user. This study analyzes the relationship between the user position variation and the wireless key generation rate with the key generation rate limit analyzed for scenarios in two static environments. The results show that in an astatic channel environment where the user positions are changing, the channel distribution is not Gaussian and the secret key generation rate is only affected by changes in the user position. The upper bound on the secret key generation rate is estimated numerically based on the channel error for the simple reflection scene. For the scattering scene, the results show that the key generation rate is high enough when the user position changes about one wavelength.
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