In aerospace telemetry, there is usually a large Doppler frequency offset, and the receiver QPSK demodulator cannot perform carrier recovery. So the large frequency offset compensation is needed. In this paper, a large frequency offset extraction method using fast Fourier transform and phase lock loop is proposed. Based on the QPSK modulation signal, a complex signal containing frequency offset information is constructed, and then the value and the sign of frequency offset is calculated by fast Fourier transform. At last, the phase error will be eliminated by PLL. The utility model has the advantages of high estimation accuracy, large capture range and short lock time. The good performance of this method for large frequency offset carrier recovery is manifested in the simulation. It can be applied to signal synchronous demodulation in satellite communication.

Joint International Conference on Astrophysics for Young Scientists (JICA) (1; 2017; Byurakan, Armenia). The First Joint International Conference on Astrophysics for Young Scientists (JICA) [Электронный ресурс]: Oktober 3-7, 2017, Byurakan, Armenia: [book of proceedings]. — Электрон. текстовые дан. (1 файл : 3,69 Мб). — Saint-Petersburg: Peter the Great St. Petersburg Polytechnic University, 2017. — Загл. с титул. экрана. — Электронная копия печатной публикации 2017 г. — Свободный доступ из сети Интернет (чтение, печать, копирование). — Adobe Acrobat Reader 7.0. — <URL:http://elib.spbstu.ru/dl/2/i17-449.pdf>.