A receiver and method for operating a receiver, in particular of a radio network, is provided, whereby the receiver includes circuit blocks in a receive path for detecting a preamble of a received signal, and a controller for controlling a receive mode. Whereby at least some of the circuit blocks are designed to be capable of being turned on for a turn-on duration and turned off for a turn-off duration. Whereby, the controller is configured to alternately turn on at least some of the circuit blocks for the turn-on duration and off for the turn-off duration during the receive mode, wherein the turn-off duration is shorter than the preamble. Whereby, the controller is configured to compare a first measured value measured in the receive path to a first threshold, and the controller is configured to change the turn-on duration and/or the turn-off duration on the basis of a result of the comparison with the first threshold, and whereby the controller is configured to compare a second measured value to a second threshold in order to detect a valid signal of the preamble and, on the basis of a result of the comparison with the second threshold, to terminate the turn-off and to drive the portion of the circuit blocks into a turned-on state for a synchronization by means of the preamble.