Large Doppler Frequency Offset Estimation for LEO Satellite Communication System based on 5G TRS

In order to solve the problem of large Doppler frequency offset (DFO) in 5G Non-Terrestrial Networks (NTN) based low Earth orbiting (LEO) satellite scenario, three DFO estimation algorithms of different complexity based on Doppler rate calculations are proposed - Firstly, TRS conjugate correlation estimator is proposed, and then least squares estimator is proposed on the basis of conjugate correlation. Then, by constructing weights, a weighted least square estimator is proposed. Finally, the DFO can be estimated according to the initial frequency offset and Doppler rate estimation. Compared with the existing algorithms, simulation results demonstrate the proposed three algorithms slightly sacrifice the complexity to improve the estimation accuracy of the Doppler rate, and has good frequency offset estimation performance under the condition of high dynamic frequency offset and low signal to noise ratio. The differences in complexity and performance of the proposed three algorithms are analyzed.