Improved Differential Correlated Joint Detection in Primary Synchronization Procedure for 3GPP LTE Downlink System

• Main Authors: Jong-Cheng Hsieh, 謝榕城
• Other Authors: 林信標
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/8534fu

碩士 === 國立臺北科技大學 === 電腦與通訊研究所 === 100 === In 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) downlink systems. The downlink transmission utilizes Orthogonal Frequency Division Multiple Access (OFDMA) as the physical layer technique. In this paper, we focus only on the downlink transmission synchronization and cell search procedure. Within recently cellular systems, user equipment (UE) must perform the cell search procedure in order to acquire symbol timing, frame timing, CFO, sector ID and group ID. Because of having the best serving base station, the UE needs to establish connection as fast as it can. Furthermore, we also know that OFDMA technique is sensitive to time and frequency synchronization errors, so we need a robust cell search procedure to help us acquire above mentioned synchronization information. In this paper, we are going to introduce an improved frequency offset detection algorithm in 3GPP LTE downlink systems. The detection algorithm including ML estimation, joint detection. The ML estimation uses the characteristics of cyclic prefix in order to obtains the symbol timing and fractional carrier frequency offset (CFO). Then, we also need to acquire the sector identification (ID) and integer CFO from joint detection in the frequency domain. We investigated two kinds of joint detection method and compared their performances. Simulation results demonstrate that the proposed method with better performance. Furthermore, the proposed method can effectively achieve the integer CFO and sector identification (ID).