Research Article
Carrier Synchronizator in Nonbinary LDPC Coded Modulation Systems
@INPROCEEDINGS{10.1007/978-3-319-78139-6_13, author={Qiang Zhang and Zhong-yang Yu and Baoming Bai}, title={Carrier Synchronizator in Nonbinary LDPC Coded Modulation Systems}, proceedings={Communications and Networking. 12th International Conference, ChinaCom 2017, Xi’an, China, October 10-12, 2017, Proceedings, Part II}, proceedings_a={CHINACOM}, year={2018}, month={4}, keywords={Pilot-aided Nonbinary LDPC High-order QAM Carrier synchronization}, doi={10.1007/978-3-319-78139-6_13} }- Qiang Zhang
Zhong-yang Yu
Baoming Bai
Year: 2018
Carrier Synchronizator in Nonbinary LDPC Coded Modulation Systems
CHINACOM
Springer
DOI: 10.1007/978-3-319-78139-6_13
Abstract
This paper proposes carrier synchronizator in a nonbinary LDPC and high-order QAM system in order to solve some relevant problems (e.g. Doppler shift, spectrum efficiency etc.) in the satellite communication. The carrier synchronizator is divided into two parts: frequency estimator and phase estimator. The frequency estimator has two steps: single pilot block-based coarse frequency estimation and multiple pilot block-based fine frequency estimation performed by an autocorrelation (AC) operation and a cross-correlation (CC) operation, respectively. Through frequency compensation, the following phase estimator is carried out by the classical maximum likelihood (ML) criterion. Simulation results show that, for a (225, 173) nonbinary LDPC code over GF(16) with a 16-QAM systems, the proposed carrier synchronizator can eliminate large Doppler shift in the presence of random phase offset with low complexity.