Abstract: Provided are a tag and a method, performed by the tag, of transmitting a response signal regarding a tag search signal. The method includes: receiving, from at least one of a plurality of slave nodes, the tag search signal including identifying data for identifying the tag; charging an energy storage element inside the tag by using the received tag search signal; obtaining the identifying data for identifying the tag from the received tag search signal; determining whether the obtained identifying data matches identification information pre-stored in the tag; and when the energy storage element is charged to a certain numerical value or above and the obtained identifying data matches the identification information pre-stored in the tag, outputting the response signal regarding the tag search signal.

Abstract: An object detection method performed by a movable device is provided. The object detection method includes emitting radio frequency signals, receiving radio frequency signals reflected by an object, obtaining N sample sequences by digitizing N radio frequency signals, N being a natural number greater than or equal to 2, from among the received radio frequency signals, obtaining a matrix including each of the N sample sequences as a column, in an order in which the radio frequency signals are received, obtaining a resulting signal by summing samples for each row of the matrix and obtaining an energy value from the resulting signal, and detecting the object based on the obtained energy value being greater than or equal to a certain threshold value.

Abstract: Provided are a tag and a method, performed by the tag, of transmitting a response signal regarding a tag search signal. The method includes: receiving, from at least one of a plurality of slave nodes, the tag search signal including identifying data for identifying the tag; charging an energy storage element inside the tag by using the received tag search signal; obtaining the identifying data for identifying the tag from the received tag search signal; determining whether the obtained identifying data matches identification information pre-stored in the tag; and when the energy storage element is charged to a certain numerical value or above and the obtained identifying data matches the identification information pre-stored in the tag, outputting the response signal regarding the tag search signal.