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Analysis of soft-decision FEC on non-AWGN channels
Junho Cho1, Chongjin Xie, Peter J Winzer
1Bell Labs, Alcatel-Lucent, 1649 Sangam-Dong, Mapo-Gu, Seoul 121-904, South Korea. junho.cho@alcatel-lucent.com
Optics Express
|March 29, 2012
Summary
Soft-decision forward error correction (SD-FEC) can improve fiber-optic communication by accounting for non-Gaussian noise. Utilizing signal correlation information offers over 3 dB coding gain, enhancing system performance.
Area of Science:
- Optical Communications
- Information Theory
- Error Correction Coding
Background:
- Soft-decision forward error correction (SD-FEC) is typically designed for additive white Gaussian noise (AWGN) channels.
- Fiber-optic communication channels often exhibit non-Gaussian and non-circularly symmetric noise, violating SD-FEC design assumptions.
Purpose of the Study:
- To quantify the impact of non-AWGN noise on SD-FEC performance in optical channels.
- To analyze the effect of noise correlations on SD-FEC performance using a conditionally bivariate Gaussian noise (CBGN) model.
Main Methods:
- Utilized a conditionally bivariate Gaussian noise (CBGN) model to represent non-AWGN in optical channels.
- Applied density evolution analysis of low-density parity-check (LDPC) codes to assess SD-FEC performance under CBGN conditions.
Main Results:
- Demonstrated that SD-FEC can achieve over 3 dB of coding gain on CBGN channels with correlated, elliptic noise.
- Quantified the performance degradation of standard SD-FEC designs when faced with non-AWGN conditions.
Conclusions:
- Noise characteristics in fiber-optic systems significantly impact SD-FEC performance.
- Exploiting correlation information in non-AWGN environments is crucial for maximizing SD-FEC benefits and improving optical transmission system detection.
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