概括
一种新的查找表方法提高了50Gb/s PAM4系统的低密度平价检查代码 (LDPC) 在非高斯噪声的性能. 这种方法在人工神经网络等效器系统中提高了0.6dB的灵敏度.
科学领域:
- 光学通信系统 光学通信系统
- 数字信号处理是数字信号处理.
- 信息理论是信息理论.
背景情况:
- 来自非线性均等器的非高斯噪声会降低高速光学系统中低密度平价检查 (LDPC) 代码的性能.
- 计算日志概率 (LLR) 的现有方法假定高斯噪声,在这些场景中是不准确的.
- 一般化互惠信息 (GMI) 经常用于预测LDPC性能,但在非线性等分后可能不可靠.
研究的目的:
- 调查非高斯噪声对25公里,50Gb/s脉冲振幅调制-4 (PAM4) 直接检测系统中的LDPC代码性能的影响.
- 提出一种新的LLR计算方法,以减轻非高斯噪声的影响,并提高LDPC的性能.
- 评估GMI在非线性均等器存在的情况下对LDPC性能的预测能力.
主要方法:
- 实施一个25公里,50Gb/s的PAM4直接检测系统.
- 使用非线性等分器,包括决策反等分器 (DFE) 和人工神经网络 (ANN) 等分器.
- 开发和应用基于查找表 (LUT) 的LLR计算方法,适用于非高斯噪声条件.
- 将拟议的基于LUT的LLR方法与传统的基于高斯的LLR计算进行比较.
主要成果:
- 拟议的基于LUT的LLR计算方法在非高斯噪声下显著提高了LDPC代码的性能.
- 与传统方法相比,在ANN等分器系统中使用拟议的方法实现了0.6dB的灵敏度改善.
- 该研究表明,当使用DFE和ANN等非线性均等器时,传统的GMI是LDPC性能的不完美预测器.
结论:
- 基于LUT的LLR计算是一种有效的策略,用于改善受非高斯噪声影响的PAM4系统中的LDPC性能.
- 这些发现突显了传统的LLR计算和GMI作为先进光通信系统性能预测器的局限性.
- 这项研究有助于为未来的高速光学网络开发更强大的纠错技术.
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