The proper statistical nature of measuring & estimating

In wireless communications, all received signals have a statistical nature. The statistical nature usually comes from a stationary environment. In order to ensure of sufficient signal strength coverage, many methods of estimating or predicting signal strength appear in technical literature. However, the improper statistical process can sometimes mislead to untrue characteristics in the wireless communications signal. This paper studies the proper means of generating statistical data for assisting with system designs in three steps: First, how to analyze the measured data by going through Ergodic processes, i.e., ensuring the ensemble average equals the time average; second, how to handle the measured data in a nonstationary environment; third, how to generate a statistical database by using estimations such as ray-tracing techniques in propagation or Rayleigh-fading simulations in data transmission. The boundary of the statistical nature and the caution of using it will be addressed in this paper as well.