In an embodiment, a method of a base station (BS) for managing an ISI in a cellular network is disclosed. The method includes receiving at least one UE-Capability information element from a UE comprising a list of CP lengths and a list of SCSs, determining a plurality of parameters associated with the UE based on the list of CP lengths and the list of SCSs, calculating at least one of a first custom CP length and a first SCS based on the plurality of parameters from the list of CP lengths and the list of SCSs, and transmitting, to the UE, a response message indicating that at least one of the first custom CP length and the first SCS is selected for managing the ISI.