Timing and Frequency Synchronization on Device-to-Device Communication in LTE-A

• Main Authors: Jie-Wen Luo, 羅傑文
• Other Authors: Jia-Chin Lin
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/jy37dt

碩士 === 國立中央大學 === 通訊工程學系 === 105 === 　　D2D has been a key development of communication in next-generation communication. However, there exist, such as interference management, mode selection, discovery and signal synchronization, occurring in scenario. Among the problems, signal synchronization is the most crucial one, especially the aspect of frequency synchronization. Intercarrier interference(ICI) may result when the orthogonality among subcarriers do not be perfectly maintained. In INC (In-Network Coverage) scenario, DUEs are in the same coverage and can achieve synchronization state via the sector searching mechanism that makes devices connect to the base station. Nonetheless, according to 3GPP Rel-12, asynchronous problems may occur in the PNC (Partial-Network Coverage) and ONC (Out-of-Network Coverage) scenarios because of different central frequencies. This issue has been discussed since 3GPP TSG RAN1 Session #79, including the position of synchronization sequence of D2D and scenario settings. 3GPP is dedicated to discussing D2D discovery methods and synchronization methods. Until now, the outcome has not been well known. 　 In this thesis, a novel procedure consisting of three steps is proposed. At first, frame timing and primary synchronization signal of D2D is searched for by autocorrelation. Second, fractional frequency offset is estimated by. At last, integer frequency offset is detected by frequency-domain matched filter. The proposed algorithm may provide accurate timing synchronization and frequency correction for D2D communication. D2D communication will operate on licensed bands in future, and the proposed method can provide connection stability for D2D communication. Therefore, the proposed technique improves the applicability of D2D communication.