The present disclosure discloses a method and a device in a communication node for wireless communications. The communication node monitors first-type information blocks in a first time window, receives a first signaling, and transmits a first radio signal; the first signaling is used for determining time-frequency resources occupied by the first radio signal; information carried by the first radio signal comprises a first difference value, a first reference power value is used for determining the first difference value, the first reference power value is a power value for a wireless transmission on sidelink; when X first-type information blocks are detected in the first time window, the X first-type information blocks respectively correspond to X first-type parameters, X is a positive integer greater than 1; the X first-type parameters are used for determining a target parameter, the target parameter is used for determining the first reference power.