Protograph-based LDPC convolutional codes for continuous phase modulation

Tarik Benaddi (1, 2, 3) , Charly Poulliat (1, 2, 4) , Marie-Laure Boucheret (1, 2, 4) , Benjamin Gadat (5) , Guy Lesthievent (3)

1 IRIT-SC - Signal et Communications
2 TéSA - Télécommunications Spatiales et Aéronautiques - Telecommunications for Space ant Aeronautics
3 CNES - Centre National d'Études Spatiales [Toulouse]
4 Toulouse INP - Institut National Polytechnique (Toulouse)
5 TAS - Thales Alenia Space [Toulouse]

The spatial coupling is an efficient technique that improves the threshold of Low Density Parity Check (LDPC) codes. In this paper, we investigate the performance of the serial concatenation of Continuous phase modulation (CPM) and LDPC convolutional codes over a memoryless additive white Gaussian noise channel. We show that coupling protographs optimized for CPM improves their performance and helps designing very good `small' protographs. Inspired from convolutional codes and thanks to the inner structure of CPM, we also introduce a new termination without rate loss but that still exhibits a coupling gain and it thus has a very good threshold. We will illustrate the behavior of different LDPC convolutional codes with different termination methods by giving some examples and studying their performance using multidimensional EXIT analysis.

Mots clés: Termination; CPM; LDPC convolutional codes; Iterative decoding; Code design; EXIT Chart

Domaines: Synthèse d'image et réalité virtuelle [cs.GR]; Traitement du signal et de l'image [eess.SP]; Traitement des images [eess.IV]; Vision par ordinateur et reconnaissance de formes [cs.CV]; Intelligence artificielle [cs.AI]

Tarik Benaddi, Charly Poulliat, Marie-Laure Boucheret, Benjamin Gadat, Guy Lesthievent. Protograph-based LDPC convolutional codes for continuous phase modulation. IEEE International Conference on Communications (ICC 2015), Jun 2015, London, United Kingdom. pp. 4454-4460. ⟨hal-01461710⟩