WDM extended reach passive optical networks using OFDM-QAM

Area of Science:

• Telecommunications Engineering
• Optical Networking
• Signal Processing

Background:

• Network operators aim to reduce broadband delivery costs by simplifying architectures.
• Integrating metro and access networks necessitates advanced solutions like Extended Reach Passive Optical Networks (ER-PONs).
• ER-PONs typically feature high data rates, extended reach, high split ratios, and WDM.

Purpose of the Study:

• To propose and demonstrate a highly spectral efficient ER-PON.
• To achieve a high split ratio and extended reach using cost-effective components.
• To analyze system performance under various modulation schemes and driving ratios.

Main Methods:

• Implementation of a 4 Gb/s Orthogonal Frequency Division Multiplexing Quadrature Amplitude Modulation (OFDM-QAM) system for upstream and downstream signals.
• Utilizing optical components optimized for Gigabit Passive Optical Networks (GPON).
• Conducting numerical analysis of different QAM orders (16, 64, 256) and electrical driving ratios.

Main Results:

• Demonstration of a spectral efficient ER-PON achieving a 256 split ratio.
• Successful 100 km reach without the need for dispersion compensation.
• Analysis of receiver sensitivities and power penalties for various OFDM-QAM configurations.

Conclusions:

• The proposed ER-PON design enables high spectral efficiency and a high split ratio.
• The system effectively utilizes GPON-optimized components for extended reach applications.
• The findings support the feasibility of cost-effective, high-performance broadband delivery networks.