Interference Analysis of EHF/THF Communications Systems with Blocking and Directional Antennas

The fifth generation wireless systems are expected to rely on a large number of wideband small cells to offload traffic from the cellular and wireless local area networks. To create such small cells, EHF and THF bands are actively explored. These frequencies are characterized by fundamentally different propagation characteristics resulting in different interference structure at the receiver compared to, e.g., microwave systems. In this paper, we study the interference structure for systems operating in EHF/THF bands by explicitly capturing three major phenomena: (i) extreme directivity of the transmit and/or receive antennas, (ii) pass loss component caused by molecular absorption and (iii) blocking of high-frequency radiation. The metric of interest is the mean interference at the receiver. Our results reveal that (i) for the same emitted energy in a Poisson field of interferers, the interference increases with the directivity of the transmit or receive antennas, (ii) blocking has a profound impact on the interference creating much more favorable conditions for communications compared to lower frequencies and (iii) the choice of the antenna model is of crucial importance for accurate performance assessment.