Embodiments of a User Equipment (UE) and methods for determination of a side-link reference signal received power (S-RSRP) are disclosed herein. The UE may receive a signal from a second UE as part of a device-to-device (D2D) communication. The UE may determine a resource element (RE) block size to be used for a determination of the S-RSRP. The RE block size may be based on a delay spread of a channel between the UE and the second UE. The UE may determine the S-RSRP based on multiple summations, sizes of which may be based on the determined RE block size.