Primary user identification when secondary user is transmitting without using Quiet Period

The goal of this paper is to identify primary (licensed) users when the secondary (non-licensed) system is transmitting without Quiet Period in the same frequency band. The paper further presents the LTE operating in TV channels, where DVB-T and PMSE transmitters are considered as primary users by default. In this context, the LTE system is acting as a secondary system which during a first step i) verifies if a TV channel is available for opportunistic access, and which during a second step ii) will start using the TV channel if the band has been previously identified as free. However, since a primary user may start transmitting anytime, the identification becomes very difficult if the LTE system continues to transmit, because a secondary receiver could detect its own secondary system rather than the primary user. This paper therefore supposes that LTE system embeds classification capabilities, allowing primary user discrimination from LTE transmissions. Finally, simulation results are showing the efficiency of the proposed classification algorithm with respect to regulatory requirements.