142 / 2016-11-09 22:16:05

An Efficient Algorithm for Estimating Carrier Frequency Offset of APSK Signal

APSK; frequency offset estimation; constellation; quartic spectrum

This paper presents an effective algorithm for estimating carrier frequency offset of APSK modulated signal. The data of the signal is obtained after the process of timing synchronization. The algorithm is based on the characteristic that the radiuses of the points of the constellation of APSK modulated signal are different. The value of the data is set to zero except the points with the smallest radius. The spectrum line of the quartic spectrum of the zeroing data is extracted to estimate carrier frequency offset. Simulation results show that this algorithm is low in complexity and highly practical. The mean square error of estimation of carrier frequency offset is lower than -80 dB when the number of symbol is 500 and the signal to noise ratio is greater than 15 dB.