Spectrally-efficient direct-detection WDM transmission systems

Shi

et al. 2018

J. Lightwave Technol.

Self Cite

mentioning

confidence: 99%

Digital Linearization of Direct-Detection Transceivers for Spectrally Efficient 100 Gb/s/λ WDM Metro Networking

Shi

et al. 2018

J. Lightwave Technol.

Self Cite

“…To cope with this growth, cost-effective optical transceivers offering low power consumption, resilience to noise and fiber impairments, and high information spectral density (ISD) play a key role. In contrast to polarization-multiplexed digital coherent systems, the simple and potentially lower cost of the optical hardware structure of single-polarization direct-detection (DD) wavelength division multiplexing (WDM) systems may make them a favorable solution for inter-data center, access, and metropolitan links/networks, provided they can meet the above-mentioned requirements [3,4].…”

Section: Introductionmentioning

confidence: 99%

Comparison of digital signal-signal beat interference compensation techniques in direct-detection subcarrier modulation systems

Galdino

et al. 2016

Opt. Express

Self Cite

Single-polarization direct-detection transceivers may offer advantages compared to digital coherent technology for some metro, back-haul, access and inter-data center applications since they offer low-cost and complexity solutions. However, a direct-detection receiver introduces nonlinearity upon photodetection, since it is a square-law device, which results in signal distortion due to signal-signal beat interference (SSBI). Consequently, it is desirable to develop effective and low-cost SSBI compensation techniques to improve the performance of such transceivers. In this paper, we compare the performance of a number of recently proposed digital signal processing-based SSBI compensation schemes, including the use of single-and two-stage linearization filters, an iterative linearization filter and a SSBI estimation and cancellation technique. Their performance is assessed experimentally using a 7×25 Gb/s wavelength division multiplexed (WDM) single-sideband 16-QAM Nyquist-subcarrier modulation system operating at a net information spectral density of 2.3 (b/s)/Hz.

“…However, it is not currently practical to install coherent technologies in such applications due to their cost-sensitive nature [1]. Thus, it is still favorable to employ simpler direct-detection (DD) wavelength division multiplexing (WDM) systems for many inter-data center, access, metro and back-haul applications [2].…”

Section: Introductionmentioning

confidence: 99%

Two-Stage Linearization Filter for Direct-Detection Subcarrier Modulation

IEEE Photon. Technol. Lett.

Maher

et al. 2016

Self Cite

A novel digital two-stage linearization filter is proposed for direct-detection (DD) systems and assessed experimentally for the first time. The performance improvement is quantified by experiments with a 7 × 25 Gb/s WDM DD single sideband 16-QAM Nyquist-shaped subcarrier modulation (Nyquist-SCM) system with a net optical information spectral density of 2.3 (b/s)/Hz. The results indicate that this technique can effectively compensate the nonlinearity caused by square-law detection while, at the same time reducing the DSP complexity, avoiding the need to perform the multiple iterations which are required in previously proposed beating interference cancellation methods.