A method of resource allocation in sidelink (SL) communication by a user equipment (UE) includes performing resource allocation across multiple SL resource pools (RPs)/carriers. The multiple SL RPs/carriers include a first SL RP/carrier having the first sub-carrier spacing (SCS) and the second SL RP/carrier having a second SCS, and resources are selected based on at least one of following conditions: selecting resources consecutive in the time domain in the second SL RP/carrier and overlapping with at least one resource or slot in the first SL RP/carrier, selecting resources in the second SL RP/carrier and overlapping with a first portion of the at least one resource or slot in the first SL RP/carrier, and avoiding selecting a slot of resources in the second SL RP/carrier where a feedback occasion overlaps in the time domain with a reserved resource in the first SL RP/carrier.