Abstract
The Nyquist wavelength-division-multiplexing technique (N-WDM) enables a solution to achieve high spectral efficiency (SE) in long-haul transmission systems. Compared to polarization-division-multiplexing (PDM) quadrature-phase-shift-keying modulation, multilevel modulation scheme such as PDM 64-ary quadrature amplitude modulation (64QAM) is much more sensitive to intrachannel noise and interchannel crosstalk caused by N-WDM. We experimentally demonstrated the generation and transmission of the 6×144-Gb/s N-WDM PDM-64QAM signal over 80-km single-mode fiber SMF-28 with erbium-doped-fiber- amplifier-only amplification. It achieved a net SE of 10 bits/s/Hz assuming 20% forward error correction overhead. This experiment was successfully enabled by digital-signal-processing (DSP) pre-equalization of transmitter-side impairments and DSP post-equalization of the channel and receiver-side impairments. Nyquist-band is considered in the pre-equalization to enhance the tolerance of the PDM-64QAM to the aggressive spectral shaping. The benefit from the proposed Nyquist-band pre-equalization scheme was also experimentally demonstrated.
| Original language | English |
|---|---|
| Article number | 6338988 |
| Pages (from-to) | 3687-3692 |
| Number of pages | 6 |
| Journal | Journal of Lightwave Technology |
| Volume | 30 |
| Issue number | 23 |
| DOIs | |
| Publication status | Published - 2012 |
| Externally published | Yes |
Keywords
- 64QAM
- Coherent detection
- Nyquist wavelength-division multiplexing
- Nyquist-band
- pre-equalization
- signal transmission
- spectral efficiency (SE)