A Dynamic Ul-Dl Reconfiguration Scheme In Lieu Of Em Radiation & Interference Based On Em Asymmetry In Mobile Communications Systems
In the context of Electromagnetic (EM) Radiation, a realistic (inhomogeneous) model for human head having
numerous tissues is analyzed with respect to an ideal (homogeneous) model. And the exposures are considered based on the
simulations based on the Specific Absorption Rate (SAR) pertaining to the head. Both models exhibit same total SAR, but in
terms of maximal and local SAR they tend to be different. In order to overcome, Base station-to-Base station (BS-to-BS) &
User Equipment-to-User Equipment (UE-to-UE) interferences arising due to asymmetric Uplink (UL) and Downlink (DL),
synchronous transmissions are deployed in Time Division Duplex (TDD) systems. But, this limits the configuration of
resources dynamically. Heterogeneous Networks (Hetnets) incorporating high power-wide area and low power-small area
create opportunities in harnessing the dynamic UL-DL feature and thereby adapting to the asymmetric UL-DL in each cell.
Electromagnetic Asymmetry (EA) means that, under the restriction of EM radiation, the equivalent bandwidth of uplink
should be narrower than that of downlink in view of the duplexing schemes. Increase in multimedia services and the wide
scale use of various applications like web browsing, real-time video and interactive games have resulted in the EA between
the uplink and downlink. This paper discusses the EM Asymmetric scenario and its design aspects, requirements and
deployment of UL-DL reconfiguration in view of EM Asymmetry.
Keywords— TDD, TD-LTE, EM Asymmetry, SAR, Inhomogeneous head model.