Techniques are provided for mitigating inter-carrier interference (ICI) due to frequency multiplexed downlink channels with mixed numerologies. For example, a base station allocates, for a user equipment (UE), a first downlink (DL) channel and a second DL channel that are frequency multiplexed in a same bandwidth part (BWP) and have different channel numerologies The base station determines a guard band interval between the first DL channel and the second DL channel based on one or more characteristics of the different channel numerologies, transmits DL transmissions to the UE, over the first DL channel and the second DL channel, using the guard band interval between the first DL channel and the second DL channel.