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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 (No. 381, Wushan Road Tianh, Guangzhou Guangdong 0, 510640, CN)
YANG, Zhibin (No. 381, Wushan Road Tianh, Guangzhou Guangdong 0, 510640, CN)
LIU, Jing (No. 381, Wushan Road Tianh, Guangzhou Guangdong 0, 510640, CN)
JI, Fei (No. 381, Wushan Road Tianh, Guangzhou Guangdong 0, 510640, CN)
YU, Hua (No. 381, Wushan Road Tianh, Guangzhou Guangdong 0, 510640, CN)
Application Number:
CN2018/112821
Publication Date:
August 15, 2019
Filing Date:
October 30, 2018
Export Citation:
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Assignee:
SOUTH CHINA UNIVERSITY OF TECHNOLOGY (No. 381, Wushan Road Tianh, Guangzhou Guangdong 0, 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 (Room 4416, BlockB Sinopec Tower,Tiyuxi Road, Tianh, Guangzhou Guangdong 0, 510620, CN)
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