Key generation rate analysis with changes in the user position

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.