Hardware-Efficient and Performance-Enhanced Joint Pulse Shaping and Dispersion Compensation for Coherent Data Center Interconnects

2026-05-25

AI Summary

This work addresses the significant increase in digital signal processing (DSP) complexity and power consumption in coherent optical communication systems operating at high baud rates with complex modulation formats, primarily caused by conventional receiver-side chromatic dispersion compensation and pulse shaping. To mitigate this, the authors propose a joint pulse shaping and chromatic dispersion pre-compensation (JFS-CD) architecture implemented at the transmitter. By co-designing the spectral characteristics of pulse shaping with the frequency-domain properties of the discrete Fourier transform, and incorporating a low-complexity squared-bound clipping (SBC) algorithm to suppress the elevated peak-to-average power ratio induced by pre-compensation, the scheme achieves the first demonstration of such joint transmitter-side processing. Experimental results show a 0.3 dB improvement in Q-factor, approximately 46% reduction in real-valued multiplications, and enhanced resilience to fiber nonlinearity and receiver IQ imbalance, all while maintaining system performance.

Abstract

With the explosion of data traffic triggered by 5G/6G and Generative artificial intelligence, coherent optical communication is moving towards higher baud rates and more complex modulation formats. This leads to a significant increase in the computational complexity and power consumption of digital signal processing (DSP) at the transmitter and receiver ends, especially in the chromatic dispersion(CD) Compensation and low roll-off shaping filter modules. We propose a joint shaping filtering and CD compensation (JFS-CD) algorithm. This algorithm moves the CD compensation to the transmitter side and utilizes the characteristics of discrete fourier transform and the spectral features of shaping filtering for integrated processing. Aiming at the high peak-to-average power ratio (PAPR) problem caused by chromatic dispersion pre-compensation, we propose a low-complexity square boundary clipping algorithm(SBC). Simulation results show that, under the premise of maintaining unchanged performance, JFS-CD can reduce the real multiplication complexity by about 46%. Meanwhile, benefiting from the suppression of the effects of system nonlinearity and receiver IQ imbalance, the joint JFS-CD and SBC scheme improves the Q-factor by about 0.3 dB in experiments compared to the traditional post-chromatic dispersion compensation scheme. This research provides a highly potential transmitter DSP solution for next-generation low-power and high-performance data center interconnects (DCI).

Problem

• chromatic dispersion compensation
• pulse shaping
• digital signal processing
• peak-to-average power ratio
• data center interconnects

Innovation

• joint pulse shaping
• chromatic dispersion compensation
• low-complexity DSP
• peak-to-average power ratio
• coherent optical communication