Terminated and Tailbiting Spatially-Coupled Codes with Optimized Bit Mappings for Spectrally Efficient Fiber-Optical Systems
Journal article, 2015

We study the design of spectrally efficient fiber- optical communication systems based on different spatially cou- pled (SC) forward error correction (FEC) schemes. In particular, we optimize the allocation of the coded bits from the FEC encoder to the modulation bits of the signal constellation. Two SC code classes are considered. The codes in the first class are protograph-based low-density parity-check (LDPC) codes which are decoded using iterative soft-decision decoding. The codes in the second class are generalized LDPC codes which are decoded using iterative hard-decision decoding. For both code classes, the bit allocation is optimized for the terminated and tailbiting SC cases based on a density evolution analysis. An optimized bit allocation can significantly improve the performance of tailbiting SC codes codes over the baseline sequential allocation, up to the point where they have a comparable gap to capacity as their terminated counterparts, at a lower FEC overhead. For the considered terminated SC codes, the optimization only results in marginal performance improvements, suggesting that in this case a sequential allocation is close to optimal.

Author

Christian Häger

Chalmers, Signals and Systems, Kommunikationssystem, informationsteori och antenner, Communication Systems

Alexandre Graell i Amat

Chalmers, Signals and Systems, Kommunikationssystem, informationsteori och antenner, Communication Systems

Fredrik Brännström

Chalmers, Signals and Systems, Kommunikationssystem, informationsteori och antenner, Communication Systems

Alex Alvarado

University College London (UCL)

Erik Agrell

Chalmers, Signals and Systems, Kommunikationssystem, informationsteori och antenner, Communication Systems

Journal of Lightwave Technology

0733-8724 (ISSN)

Vol. 33 7 1275-1285 7005396

Areas of Advance

Information and Communication Technology

Subject Categories

Telecommunications

Communication Systems

Infrastructure

C3SE (Chalmers Centre for Computational Science and Engineering)

DOI

10.1109/JLT.2015.2390596