Eduardo Mateo

Trans-pacific transmission of quad-carrier 1Tb/s DP-8QAM assisted by LUT-based MAP algorithm

1Tb/s quad-carrier DP-8QAM transmission over 9280 km is reported at a spectral efficiency of 4.54 b/s/Hz thanks to the proposed joint transmitter maximum a posterior (MAP) pre-distortion and receiver correction scheme.

Optimized BICM-8QAM formats based on generalized mutual information

Through the expansion of non-Gray-mapping symbols, the pre-FEC and post-FEC Q-factors of the proposed optimized Circle-8QAM outperform Circle-8QAM and Star-8QAM by ~0.3 dB and ~0.6dB at the coding rate of 0.8 in experiments.

Transoceanic transmission of dual-carrier 400G DP-8QAM at 121.2km span length with EDFA-only

400-Gb/s dual-carrier DP-8QAM transmission over 6,787 km is reported at 121.2km span length, the longest to date with EDFA only. Spectral efficiency of 4.54 b/s/Hz is achieved thanks to Nyquist shaping and nonlinear compensation techniques.

Real-time Transoceanic Transmission of 1-Tb/s Nyquist Superchannel at 2.86-b/s/Hz Spectral Efficiency

Real-time 1-Tb/s superchannel transmission over 5,400-km using 100-GbE based subcarriers was achieved with an optical bandwidth of 350-GHz. The distance was further extended to 7,200-km by using digital Nyquist-shaped subcarriers with 1-dB margin.

Comparison of modulation formats based on generalized mutual information

16QAM is found to achieve the lowest SNR penalty against the Shannon limit at the GMI of 2~3 bits/channel use compared to the analyzed 2- and 4-dim modulation formats. The FEC OSNR limit of 16QAM is measured to require ~1 dB less than 8QAM at the same GMI of 2.4 bits/channel use.

Dual-optical-carrier 1-Tbps channel transmission over 4,400-km using RF sub-band multiplexing

A dual-carrier 1-Tbps transmitter carrying multiple Nyquist DP-16QAM sub-bands was implemented using novel RF sub-band multiplexing with integrated IQ mixers. 3×1-Tbps channels were transmitted over 4,400-km EDFA-only SMF link with 6.1-b/s/Hz spectral efficiency.

Technologies for the mitigation of transmission impairments in ultra-long haul submarine networks

The capacity of submarine systems has experienced an unprecedented growth with the dawn of the digital coherent era. This success relies greatly on the ability to compensate for propagation impairments in the line terminal equipment by means of digital signal processing (DSP). The continuous exponential growth of silicon integration has enabled the fabrication of powerful digital processors operating at very high speed. The implementation of high order modulation, polarization demultiplexing, spectral shaping, soft-decision FEC or impairment compensation in the digital domain has revolutionized the industry of optical communications. In particular, the ability to compensate linear and nonlinear transmission impairments has drastically changed the way that submarine cables are designed, resulting in a dramatic growth of the spectral efficiency of transoceanic cables. This chapter explains the technologies employed for the compensation of propagation impairments in ultra-long haul submarine systems, emphasizing digital techniques for the compensation of dispersion and fiber nonlinear effects.