In-Band Emission in LTE-A D2D: Impact and Addressing Schemes In recent years, the device-to-device (D2D) proximity services in the long term evolution advanced (LTE-A) system drew much attention and is now being investigated and standardized in LTE Release-12. Device discovery is a fundamental aspect of D2D proximity services, allowing discovery user to advertise its presence and/or discover others in its neighborhood. Due to the essential nature of D2D networks, the in- band emission emerges as a critical issue that impacts the in-band coexistence of D2D and cellular systems. This paper systematically studies the in-band emission issue, including its modeling, the impact on cellular system and the potential schemes to address this issue, which is further evaluated by system simulations. It is shown that the impact of the in-band emission could be addressed with the resource grouping method and/or the power control method.