Method for realizing initial synchronization of TD-LTE (Time Division-Long Term Evolution) digital relay technology

The invention discloses a method for realizing the initial synchronization of a TD-LTE (Time Division-Long Term Evolution) digital relay technology, relating to traffics or facilities applicable to a wireless communication network. The method comprises the following steps of: carrying out low-pass filtering on data subjected to A/D (Analog-Digital) sampling, and carrying out PSS (Primary Synchronization Signal)-slippage-related detection so as to obtain the IDs (Identifiers) and PSS positions of cells in a cell group; detecting CP types of positions of OFDM (Orthogonal Frequency Division Multiplexing) symbols where PSSs are located; finding out positions of SSSs (Secondary Synchronization Signals) according to the PSS positions and the CP types, carrying out SSS-related detection, and finishing front/rear half frame detection and cell ID searching; and finding out the position of a PBCH (Physical Broadcast Channel), solving the PBCH to obtain system bandwidth, and returning to control A/D sampling, thereby achieving the initial synchronization. The method has the advantages that the initial synchronization is realized by selecting an appropriate sampling frequency on the premise that a relay does not know the downlink bandwidth, the coarse timing synchronization of the symbols is achieved, the CP type is determined, the position of the PBCH is found out, and the PBCH is solved, so that the system bandwidth, system frame number and base station antenna configuration are obtained.