Selection of time-frequency resources, for autonomous mode operation of V2V UEs, may be performed based on measurements of power transmitted by other UEs and received sidelink control information (SCI) transmitted by the other UEs. Based on these measurements, the UE may selectively exclude spectrum resources, from the set of possible resources, to obtain a final set of resources from which the UE may select resources to use for transmitting. In some implementations, the exclusion of the resources may be based on an iterative operation in which a power threshold value is incrementally modified until a candidate number of resources are available. Additionally, in some implementations, UE priority assignments may be used to obtain the power threshold value for a particular UE.