8 Tb/s (80 × 107 Gb/s) DWDM NRZ-VSB transmission over 510 km NZDSF with 1 bit/s/Hz spectral efficiency

121.9-Gb/s PDM-OFDM Transmission With 2-b/s/Hz Spectral Efficiency Over 1000 km of SSMF

“…The cyclic prefix required for the mitigation of chromatic dispersion is dependent on the bandwidth of the OFDM signal and the desired transmission distance [15]. A good estimate for the required guard time is (2) where represents the chromatic dispersion of the desired transmission distance [s/m], is the effective bandwidth of the modulated OFDM signal as defined in (1), is the speed of light [m/s] and represents the center frequency of the OFDM band [Hz]. For a 1000-km link of SSMF with 16-ps/nm/km chromatic dispersion a minimal cyclic-prefix guard band of ns/OFDM symbol is required in this configuration.…”

“…The reduction of the width of the OFDM bands has some implications on the configuration and the performance of the system. According to (2), the minimum required guard time in this case is about 1 ns/OFDM symbol instead of the 3.9 ns/OFDM symbol required for the single band configuration. This results in a reduction of the cyclic prefix overhead with a factor of four to less than 1%.…”

“…100 Gigabit Ethernet (100 GbE) is considered to become the next generation Ethernet standard for IP networks [1]. Consequently, research has recently accelerated into finding appropriate long-haul Ethernet transport solutions for the physical layer [2]- [4]. In the short term, multi-wavelength transport might provide a solution for 100-Gb/s Ethernet, but in the long run a single-wavelength solution will be the most cost-effective approach.…”

“…On a 100-GHz grid, 107-Gb/s vestigial sideband (VSB) OOK transmission has been realized over 510 km [2], 107-Gb/s NRZ-DQPSK over 1,200 km [3], and 100-Gb/s DQPSK-modulated coherent-WDM over 1,300 km [4]. However, in these experiments direct detection is employed, resulting in a limited chromatic dispersion (CD) and polarization mode dispersion (PMD) tolerance.…”

100 Gb/s DQPSK field trial: Live video transmission over an operating LambdaXtreme® network

“…Ten channels were transmitted over 400 km with a spectral efficiency (SE) of 0.7 b/s/Hz (143 GHz channel spacing). Currently, the availability of mature high-speed electronics and optoelectronics is limited and thus most binary 100 Gb/s demonstrations have occurred in research labs [8,32,36,37,39,50]. In an effort to improve the spectral efficiency and reach, more advanced modulation formats are being explored [12,47].…”