Abstract
We study a turbo equalization scheme based on low-density parity-check (LDPC) coded turbo equalization (TE). This scheme is suitable for simultaneous: (i) suppression of intrachannel nonlinearities, (ii) chromatic dispersion compensation, and (iii) polarization-mode dispersion (PMD) compensation. LDPC coding is based on large girth (g > 8) block-circulant codes, and maximum a posteriori probability (MAP) equalizer is based on Bahl-Cocke-Jelinek-Raviv (BJCR) algorithm. The ultimate channel capacity limits, assuming an independent identically distributed (i.i.d.) source are reported as well. In the presence of intrachannel nonlinearities the LDPC-coded TE provides almost 12 dB improvement over BCJR equalizer at BER of 10-8. For an NRZ system operating at 10 Gb/s with residual dispersion of 11200 ps/nm and for differential group delay of 50 ps, the LDPC-coded TE is only 1 dB away from the i.i.d channel capacity. The efficiency of LDPC-coded TE in PMD compensation is demonstrated experimentally, with decoding performed off line.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 73-83 |
| Number of pages | 11 |
| Journal | IEEE Journal on Selected Areas in Communications |
| Volume | 26 |
| Issue number | 6 |
| DOIs | |
| State | Published - Aug 2008 |
Keywords
- Fiber-optics communications
- chromatic dispersion
- intra-channel nonlinearities
- low-density parity-check (LDPC) codes
- polarization-mode dispersion (PMD)
- turbo equalization
ASJC Scopus subject areas
- Computer Networks and Communications
- Electrical and Electronic Engineering