Radar in-band interference effects on macrocell LTE uplink deployments in the U.S. 3.5 GHz band

Abstract

National Telecommunications and Information Administration (NTIA) has proposed vast exclusions zones between radar and Worldwide Interoperability for Microwave Access (WiMAX) systems which are also being considered as geographic separations between radars and 3.5 GHz Long Term Evolution (LTE) systems without investigating any changes induced by the distinct nature of LTE as opposed to WiMAX. This paper performs a detailed system-level analysis of the interference effects from shipborne radar systems into LTE systems. Even though the results reveal impacts of radar interference on LTE systems performance, they provide clear indications of conspicuously narrower exclusion zones for LTE vis-à-vis those of WiMAX and pave the way toward deploying LTE at 3.5 GHz within the coastline populous areas.

Joint Bi-Static Radar and Communications Designs for Intelligent Transportation

“…This brings performance gain to superposition, as will be shown later. Using (16) and following the same procedures as those used to derive (8), one has the probability of false alarm in the superposition scheme as…”

“…The first area focuses on the coexistence or cooperation of radar and communications. For example, in [8] and [9], the effects of interference were evaluated. In [10], interference cancellation was considered.…”

PSUN: An OFDM-Pulsed Radar Coexistence Technique with Application to 3.5 GHz LTE

“…In [11], it is suggested that the secondary communication system utilizes information of the incumbent radar that is provided by a database. In [12], impacts of interference from shipborne radars to LTE systems are studied. An eNodeB's signal-tointerference-plus-noise ratio (SINR) plummets when hit by radar pulses, but an LTE system is able to recover during the time between radar pulses.…”

“…The authors concluded that the UE throughput loss in the uplink direction is tolerable even with a radar deployed only 50 kilometers away from the LTE system. In [13], the study in [12] is extended. The authors studied impacts of shipborne radars that operate in the same channel and are located in the vicinity of a 3.5 GHz macrocell and outdoor small-cell LTE systems.…”

“…In [14], on the other hand, it is concluded that LTE systems are unable to cope well with narrowband bursty interference on the downlink. Our work is distinguished from [9][10][11][12][13][14] because this paper studies how to actually cancel radar interference, while only feasibility of coexistence was discussed in the prior studies.…”