The Study And Simulation On The Large Time And Frequency Offset Estimation Algorithm Based On LTE

The large area coverage and high speed scene can bring some problems such as transmission delay and Doppler frequency offset which will strongly influence the performance. This paper mainly introduces the design of time offset estimation algorithm and frequency offset estimation algorithm based on LS (Least Square) and phase impact under high-speed running scene.The large time offset estimation algorithm puts forward a new joint time offset estimation algorithm based on the combination of LS and phase impact. This algorithm processes the small RB configuration (below 20 RB) and large RB configuration (more than 20 RB) separately. The algorithm can calculate simply and simplify the computation of large RB configuration greatly.Frequency offset estimation under high-speed scene is based on the frequency offset estimation judged by frequency offset symbol and the maximum likelihood (ML) estimation. After analyzing the two estimations’ performance, it puts forward a joint frequency offset estimation algorithm. The analysis shows that as long as the time bias is less than CP length, the frequency offset estimation judged by frequency offset symbol can make an accurate estimation, but it is sensitive to noise. In the context of high SNR, Maximum likelihood estimation can get an accurate estimation, but at the same time, it is sensitive to time bias. Combining the advantages of the above mentioned algorithms, the joint frequency offset estimation algorithm can better adapt to the high-speed scenarios. It has important instructional significance in practice.