Abstract:
In high dynamic communication environment, Doppler frequency shift caused by relative motion will introduce residual frequency offset into the baseband signal obtained by downconversion of the receiver, resulting in phase deviation of the baseband signal. Accurate estimation of frequency offset is an important way to improve the communication quality in high dynamic environment. The traditional method usually estimates the carrier frequency offset value by one-dimensional search of the spectrum obtained by Fast Fourier Transform (FFT), which can only estimate the integral frequency point. In order to further improve the accuracy of frequency offset estimation, this paper proposes an interpolation detail search (IDS) algorithm based on cubic Farrow structure. Based on the rough spectrum obtained by FFT, the proposed approach uses cubic interpolation with Farrow structure to obtain more accurate fractional frequency point. Over the Additive White Gaussian Noise (AWGN) channel, the simulation results show that the algorithm performs quite close to the Cramer-Rao bound (CRB) under the condition of 16 multiples interpolation, and the accuracy loss is only 1.2 dB, which has good estimation performance.