DMT Modulation With Adaptive Loading for High Bit Rate Transmission Over Directly Detected Optical Channels

Abstract

In this paper, we present the design and analysis of an adaptive cost-effective discrete multitone transponder (DMT) using direct detection (DD) suitable for data center interconnections. Levin Campello margin adaptive (LC-MA) algorithm is applied to the transponder digital signal processing modules to enhance fiber chromatic dispersion (CD) resilience, while achieving highdata rate transmission. The bit error rate (BER) performance and the rate/distance adaptive capabilities of the proposed transponder have been numerically analyzed and compared to bandwidth variable uniform loading, taking into account the transmission impairments at the varying of the fiber length. Specifically, the performance of the designed transponder has been assessed from 20 to 112 Gb/s, extending the achievable reach at 50 Gb/s beyond 80 km of standard single mode fiber (SSMF). The numerical simulations have been compared with experimental results, evidencing good agreement in presence of transmission impairments.

Bit- and Power-Loading—A Comparative Study on Maximizing the Capacity of RSOA Based Colorless DMT Transmitters

“…In general, DMT has been used to maximize capacities of bandwidth limited intensity modulated direct detected (IM-DD) systems [25,[34][35][36]. DMT is a type of OFDM with real-valued output signals that can be easily detected with inexpensive direct detection receivers.…”

Meeting the future metro network challenges and requirements by adopting programmable S-BVT with direct-detection and PDM functionality

“…Thus, optical implementations based on simple transmitter/receiver cost-effective ar-hardware limitations (e.g. digital-to-analog converter, DAC, bandwidth) on the system performance can be reduced [7].…”

“…and optimized m-QAM constellations (m = 2 l ; 2 ≤ l ≤ 8), according to the BL/PL algorithm for adaptive mapping [7]. In particular, the SNR per subcarrier is estimated to activate the BL/PL algorithm at the transmitter side; the network experience/information about the channel is improved [7].…”

“…In particular, the SNR per subcarrier is estimated to activate the BL/PL algorithm at the transmitter side; the network experience/information about the channel is improved [7]. Then, training symbols (TS) are added to properly equalize data at the receiver side.…”

“…Hence, increased overhead is needed in comparison with independent equalization. The Levin Campello rate adaptive BL/PL algorithm is applied for maximizing the capacity of each slice, corresponding to a polarization component, at the target performance [7].…”