Doppler rate estimation scheme for UFMC based LEO satellite communication system

As communication quality and stability are seriously impacted by high Doppler rate in low earth orbit (LEO) satellite communication system, it is quite important and imperative to compensate high Doppler rate precisely. Due to the frequency shift insensitivity feature of Zadoff-Chu (ZC) sequence, this paper presents a Doppler rate estimation algorithm based on ZC sequence in LEO universal-filtered multi-carrier (UFMC) system. According to the principle of second order difference (SOD), Doppler rate can be estimated by calculating conjugate multiplication three times between received signal and native ZC sequence. This algorithm is first used in UFMC system and don't need the Doppler shift pre-estimation. In the scenario of LEO satellite, the simulation results show that the normalized Doppler rate estimation range of this algorithm is limited within (−0.5, 0.5). If the absolute value of normalized Doppler rate is less than 0.4, mean square error (MSE) performance of Doppler rate is good and acceptable. The proposed algorithm is suitable for LEO satellite communication system.