Research And Implementation Of Timing And Frequency Synchronization For OFDMA System In LTE

With the development of LTE technology in the world(especially China), most of equipment provider for LTE technology continues to increase the investment to ensure hold the LTE technology and to lead the development of LTE industry. LTE test technology has become the focus of research in the field of mobile communication. The key technology used in LTE system is OFDMA technology, although OFDMA systems has many advantages, but it requires a very strict synchronization, so that the research on time and frequency synchronization algorithm has become the key to improve the performance of LTE test technology( the BER and MSE as the reference index).This paper analyzes the impact of timing offset and frequency offset to the LTE system brings. LTE system composed by the TD-LTE and FD-LTE.Currently TD-LTE system is used in China, so the focus of this research is the TD-LTE system synchronization algorithms. This paper analyzes the time and frequency synchronization algorithm suiting for the TD-LTE system and basing on frequency training sequence and analyzes classical synchronization algorithms. The paper proposes a new synchronization algorithm based on the training sequence. Finally, the paper gives the comparison of the simulation results and performance of these algorithms, at the same time analyzes the computational complexity of these algorithms. The performance of improved algorithms compared with the classical algorithms is: it eliminates the platform phenomenon of SC in timing estimation, and eliminates the effect of Minn’s and Park’s side beam. The estimation of frequency offset has an order of magnitude increase compared with SC in MSE.Furthermore, it analyzes the algorithms(M-part algorithm) using its own time-frequency synchronizing signal synchronized suiting for TD-LTE system, the paper proposes a new synchronization algorithm based on the training sequence. Finally, the paper gives the comparison of the simulation results and performance of these algorithms, at the same time analyzes the computational complexity of these algorithms. The performance of improved algorithms compared with the classical algorithms: it eliminates the offset impact and improves the performance of timing estimation in multipath channel. The frequency offset estimation algorithm has a more obvious improves compared with original algorithm.Finally, the paper builds simulation platform of LTE and analogs LTE system. Two kinds of time-frequency synchronization algorithm are applied to LTE system and select the best synchronization algorithm derived LTE test solutions(new primary synchronization signal synchronization algorithm). It realizes the function interface of these parameters calculation and to package using VC++ software programming. And it is called for other system.