The disclosure provides a method and a device for use in a communication node for wireless communications. The communication node receives first information and second information, and transmits a first signal; wherein the first information and the second information are used for determining a first time-frequency resource pool and a second time-frequency resource pool respectively, the first signal occupies a target time-frequency resource block; a number of resources occupied in time domain by any one first-type time-frequency resource block in the first time-frequency resource pool is not equal to a number of resources occupied in time domain by any one second-type time-frequency resource block in the second time-frequency resource pool; the target time-frequency resource block belongs to the first time-frequency resource pool or the second time-frequency resource pool. The disclosure improves random access performances.