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Title:
OFDM-IM SYSTEM FREQUENCY OFFSET ESTIMATION METHOD
Document Type and Number:
WIPO Patent Application WO/2019/153801
Kind Code:
A1
Abstract:
The present invention provides an OFDM-IM system frequency offset estimation method. The method comprises: S1, performing preliminary frequency offset compensation on a receiving signal subjected to non-uniform frequency offset by using a two-step method: (1) resampling and down conversion; (2) unified compensation on residual frequency offset ε; in step (2), using the sum of energy of null sub-carriers as a cost function, obtaining an initial estimation value of ε by means of one-dimensional search, and performing preliminary compensation; S2, estimating positions of non-activated sub-carriers in the OFDM-IM system by means of the signal subjected to preliminary compensation; S3, assigning certain weights to the estimated sub-carriers, the energy of the estimated sub-carriers being added into the cost function according to different weights, obtaining a final estimation value of ε by means of one-dimensional search on ε, and performing secondary compensation. The sub-carriers of the OFDM-IM adopted by the present invention are partially activated. It means that in addition to the initially set null sub-carriers, the energy of the non-activated sub-carriers can be utilized. Therefore, the present invention optimizes estimation of Doppler frequency shift by utilizing the non-activated sub-carriers.

Inventors:
CHEN FANGJIONG (CN)
YANG ZHIBIN (CN)
LIU JING (CN)
JI FEI (CN)
YU HUA (CN)
Application Number:
CN2018/112821
Publication Date:
August 15, 2019
Filing Date:
October 30, 2018
Export Citation:
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Assignee:
UNIV SOUTH CHINA TECH (510640, CN)
International Classes:
H04L27/00; H04L5/00
Foreign References:
CN108418772A2018-08-17
CN107231176A2017-10-03
CN106992848A2017-07-28
US20170180032A12017-06-22
Attorney, Agent or Firm:
YOGO PATENT & TRADEMARK AGENCY LIMITED COMPANY (510620, CN)
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