Coexistence between DTV and LTE in the 700 MHz band -

Abstract

The introduction of LTE in the UHF band requires a careful analysis of the possibility of coexistence between the mobile service and the broadcasting service in the same or adjacent bands. In this paper, we analyze the coexistence between LTE and Digital TV in the 700 MHz in order to propose operation guidelines such that LTE does not cause any interference to the existing broadcasting service. Our objective is to study the feasibility of the proposed Out of Band Emission requirements and their effect on the broadcasting service. We have shown that with the 3GPP proposed Out of Band (OOB) emission level of -25 dBm-8MHz, it is not possible to have coexistence under normal operating conditions. However, we show that this coexistence is possible when we use lower OOB levels that reflect higher restrictions on the LTE transmit power even without the use of additional filters. We then propose alternate solutions to keep the initially proposed high OOB levels and still mitigate interference by having reduced DTV capacity or equivalently lower required signal to noise ratio (SNR). Most importantly, we propose a new carrier aggregation method that allows us to reduce the level of interference obtained with low OOB restrictions. We also perform different analysis to show the effect of each operating parameter on coexistence and interference