Interference and SINR in Millimeter Wave and Terahertz Communication Systems With Blocking and Directional Antennas

The fifth generation wireless systems are expected to rely on a large number of small cells to massively offload traffic from the cellular and even from the wireless local area networks. To enable this functionality, mm-wave (EHF) and Terahertz (THF) bands are being actively explored. These bands are characterized by unique propagation properties compared with microwave systems. As a result, the interference structure in these systems could be principally different to what we observed so far at lower frequencies. In this paper, using the tools of stochastic geometry, we study the systems operating in the EHF/THF bands by explicitly capturing three phenomena inherent for these frequencies: (1) high directivity of the transmit and receive antennas;( 2) molecular absorption; and (3) blocking of high-frequency radiation. We also define and compare two different antenna radiation pattern models. The metrics of interest are the mean interference and the signal-to-interference-plus-noise (SINR) ratio at the receiver. Our results reveal that: (1) for the same total emitted energy by a Poisson field of interferers, both the interference and SINR significantly increase when simultaneously both transmit and receive antennas are directive and (2) blocking has a profound impact on the interference and SINR creating much more favorable conditions for communications compared with no blocking case.