Performance Enhancement of Probabilistically Shaped OFDM Enabled by Precoding Technique in an IM-DD System
| Autor: | Kaiquan Wu, Ming Chen, Jie Ma, Jing He |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Computer science
Orthogonal frequency-division multiplexing Autocorrelation 02 engineering and technology Precoding Multiplexing Atomic and Molecular Physics and Optics Discrete Fourier transform QAM 020210 optoelectronics & photonics 0202 electrical engineering electronic engineering information engineering Low-density parity-check code Algorithm Circulant matrix |
| Zdroj: | Journal of Lightwave Technology. 37:6063-6071 |
| ISSN: | 1558-2213 0733-8724 |
| Popis: | Probabilistically shaped orthogonal frequency-division multiplexing (PS-OFDM) signal is proposed and experimentally demonstrated in a low-cost intensity-modulation and direct-detection (IM-DD) system for optical access networks. The concatenation of constant composition distribution matcher (CCDM) and low-density parity-check (LDPC) code sequentially implements probabilistic amplitude shaping (PAS) and channel coding. Thanks to the precoding scheme, all data subcarriers can be treated equally by one optimized probabilistic distribution. Experimental results demonstrate that constant amplitude zero autocorrelation sequence (CAZAC) precoding can offer optimal performance compared to orthogonal circulant transform (OCT) precoding and discrete Fourier transform spread (DFT-spread) in terms of increasing generalized mutual information (GMI) and reducing PAPR. Moreover, probabilistically-shaped 64-QAM OFDM signal can provide shaping gains of 1.04/0.94/0.64 dB at 4.0/3.6/3.0 bits/QAM symbol compared to traditional 64-QAM OFDM signal. Meanwhile, compared to traditional 16-QAM OFDM, it can offer shaping gains of 1.64/0.64 dB at 3.6/3.0 bits/QAM symbol. In addition, net data rate ranging from 32.66 to 43.55-Gb/s over 20-km single mode fiber (SMF) can be achieved by only adjusting the probabilistic distribution. |
| Databáze: | OpenAIRE |
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