Method and device for the synchronization between a base radio station and a mobile radio station in a digital radiomobile system

摘要

PCT No. PCT/EP90/02296 Sec. 371 Date Aug. 14, 1992 Sec. 102(e) Date Aug. 14, 1992 PCT Filed Dec. 20, 1990 PCT Pub. No. WO91/10305 PCT Pub. Date Jul. 11, 1991.Synchronization is provided between a mobile radio station and a base station in a digital radiomobile system TDMA where the base station transmits a timeslot containing a preset frequency sinusoid. The method samples (according to different embodiments) the baseband demodulated signals and measures the phase increases between two subsequent samplings. Increases are compared with an intermediate threshold value between 0 DEG and 180 DEG to construct a vector formed by a series of values, the current sum of which is calculated. The minimum value of this sum is then identified to approximately synchronize the mobile station with the timeslot containing the sinusoid. Afterwards, the frequency offset between the local oscillator frequency and the base station oscillator frequency is calculated and corrected in order to correctly identify the timeslot containing the preamble for fine synchronization. Then the decoding of the message containing the station and the frame data is performed. The device performs this method, for instance with an implementation by means of a programmed processor.