The present disclosure relates to a method for synchronizing a radio device with a network node of a Global System for Mobile Communications, GSM, radio communication system. The method comprises obtaining a reference array based on a known training sequence, TSC, of a synchronization burst, SB, of a synchronization channel, SCH, of the network node. The method also comprises receiving an SB including the TSC from the network node and forming a received array. The method also comprises comparing the reference array to the received array for finding a sequence of the received array which has identity with the reference array, and thereby finding the position of the TSC in the received SB. The method also comprises determining whether the identity of the found sequence with the reference array is above a predefined threshold, in which case the radio device can be time synchronized based on the found TSC.