Journal of Xidian University

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Analysis and optimization of the LDPC code on the land mobile satellite channel

DAI Jingke1;LIN Kailiang2   

  1. (1. Information Engineering Department, Rocket Force Univ. of Engineering, Xi'an 710025, China;
    2. School of Science, Northwest A&F Univ., Xi'an 712100, China)
  • Received:2017-09-06 Online:2018-06-20 Published:2018-07-18

Abstract:

The low-density parity-check (LDPC) code is applied to the land mobile satellite (LMS) channel with Shadowed-Rician fading, where both of symmetry and stability conditions are proven, and the Shannon limit is calculated. The decoding thresholds are obtained based on density evolution, and the degree distributions of irregular codes are optimized using differential evolution. Simulation results show that the thresholds well predict the code performance, and that the optimized code has a threshold within 0.1dB of the Shannon limit. With the same code-length, the optimized code outperforms both the regular code and irregular code employed by the Digital Video Broadcasting-Satellite-Second Generation (DVB-S2), indicating its advantage of information transmission over the LMS channel.

Key words: low density parity check codes, shadowed-Rician channel, density evolution, decoding threshold, optimization