An analytical statistical model for the RMS delay spread parameter in millimeter frequencies

A new statistical model for rms delay spread is presented. The model has been developed under the assumption of the existence of two paths (two-path model). It is assumed that the amplitude of each path follows the so-called log-Student distribution with one degree of freedom, while the differential propagation delay of the two paths follows the uniform distribution. The parameters involved with the model are m_z and s_z the mean and standard deviation of the ratio of the two paths’ amplitudes. Theoretical curves for τ_rms as well as for the mean and standard deviation of τ_rms are plotted for different values of m_z and s_z. These curves are extremely useful for the choice of the parameters of the model for different cases. In order to examine the validity of the new model, measurements from the literature have been collected and compared with the theoretical results. In all cases a very good agreement, according to the X-square criterion, between theoretical and experimental curves has been observed. As a result, the new model can be used by system engineers for the development of wireless high bit-rate digital systems that will not suffer from intersymbol interference.