公开(公告)号：US20210044464A1

公开(公告)日：2021-02-11

申请号：US16967734

申请日：2018-10-30

Applicant: SOUTH CHINA UNIVERSITY OF TECHNOLOGY

Inventor： Fangjiong CHEN ,  Zhibin YANG ,  Jing LIU ,  Fei JI ,  Hua YU

IPC: H04L27/00 ,  H04L27/26 ,  H04L5/00

Abstract: The invention provides a frequency offset estimation method for an OFDM-IM system. The method includes: S1. performing preliminary frequency offset compensation on a received signal subjected to non-uniform frequency offset by using a two-step method of: (1) resampling and down conversion; and (2) unified compensation for residual frequency offset ε, wherein in the step (2), a sum of energy of null sub-carriers is used as a cost function, an initial estimation value of ε is obtained by one-dimensional search, and the preliminary compensation is performed; S2. estimating positions of non-activated sub-carriers in the OFDM-IM system by using the signal subjected to the preliminary compensation; and S3. assigning certain weights to the estimated sub-carriers, adding energy of the estimated sub-carriers into the cost function according to different weights, obtaining a final estimation value of ε by the one-dimensional search performed on ε, and performing secondary compensation.