Estimating channel performance for time invariant channels

It is shown that estimating the coherence bandwidth (β_c) of a static WLAN channel from frequency domain snapshot measurements using the complex autocorrelation function, commonly reported in the literature, is wrong and meaningless. In such cases the channel is time invariant or non-fading but time variant theories are mistakenly applied. An alternative parameter that estimates the distortionless transmission bandwidth (DTB) of the non-fading channel is proposed and used to characterise a line of sight, indoor microcell, at millimetre waves.