Cost-effective single-lane 112  Gb/s solution for mobile fronthaul and access applications

Area of Science:

• Optical communications
• Signal processing
• Fiber optics

Background:

• High-speed optical transmission systems are crucial for modern data networks.
• Signal impairments like chirp-induced skew limit transmission performance.
• Effective equalization techniques are needed to overcome these limitations.

Purpose of the Study:

• To experimentally demonstrate 112 Gb/s PAM-4 signal transmission over 30-km standard single-mode fiber.
• To investigate and compare the performance of Feed-Forward Equalizer (FFE), Volterra Filter (VF), and Maximum Likelihood Sequence Estimator (MLSE) equalization schemes.
• To identify the most effective equalization strategy for mitigating signal distortion and improving system performance.

Main Methods:

• Experimental setup for 112 Gb/s PAM-4 signal transmission over 30-km standard single-mode fiber.
• Implementation and comparison of FFE, VF, and MLSE equalization techniques.
• Analysis of signal skew distortion and error floor reduction capabilities of each scheme.

Main Results:

• Volterra filter components (|x| and x|x|) effectively reduce chirp-induced signal skew distortion.
• A 4-state MLSE successfully eliminates the error floor.
• FFE performance is inferior to VF combined with a 4-state MLSE, even with a 64-state MLSE.

Conclusions:

• VF and MLSE offer superior performance for high-speed optical transmission compared to FFE.
• Optimized equalization strategies are vital for achieving reliable long-haul, high-bit-rate optical communication.