Gpp Oriented Design And Optimization Of Lte Cell Search And Downlink Synchronization

LTE adopts the OFDMA multiple-access scheme in downlink. Completing the time and frequency synchronization of receiver and transmitter through the cell search and downlink synchronization process is a critical step of the OFDM receiver design. Precision of time and frequency synchronization have an important impact on the performance of entire system. Therefore, the cell search and downlink synchronization process has a crucial role and this research work has a very important significance.A research focus of this paper is the key algorithm of cell search and downlink synchronization process, including capture and tracking stages. First, the author proposed a way to reduce complexity of PSS detection by circular convolution. Compared with the piecewise linear convolution method, the points of FFT/IFFT has dropped by half. Second, in the tracking stage, a scheme of using reference signal and loop filter to achieve precise timing is proposed. In addition, the author discuss the CP type detection, frequency offset estimation, SSS detection and frequency tracking algorithms. Then a detailed design of TD-LTE cell search and downlink synchronization process is given in this paper and highlights the optimization process based on Intel GPP platform.The test results show that this scheme can well complete the cell search and a downlink synchronization process and can complete the timing and frequency synchronization quickly and accurately on the GPP platform. Timing synchronization is accurate to several samples and frequency synchronization can be accurate to several tens of Hertz, ensuring that the receiver has a good performance.