Power amplifier transient of LTE modem is discussed. In current LTE specification, the requirement of power amplifier transient period for LTE modem is within 40 µs. Under this requirement, non-negligible inter-carrier interference (ICI) can be observed for both of normal cyclic prefix (CP) (= 4.7 µs) and extended CP (= 16.7 µs). We analyze the ICI in terms of the transient response of power amplifier and propose ICI mitigation schemes: 1) digital pre-distortion at transmitter 2) low complexity multi-tap equalization at receiver based on the ICI analysis.