We study how UE-to-UE interference impacts the performance, considering transmitter out-of-band (OOB) emissions and receiver blocking characteristics for homogenous 20 MHz LTE systems. For co-existing TDD systems on different carrier frequencies within the same band, UE-to-UE interference may occur in certain situations. The impact of such interference is evaluated for a hotspot scenario and compared to a uniform user distribution scenario, and is found to be significantly worse. When the number of scheduled users in the aggressor cell is high (e.g. > 2), then receiver blocking impact, rather than the OOB emission, dominates the interference performance in hotspot scenario. Consequently, guard bands cannot be used to mitigate the receiver blocking impacts.