Beyond QPSK and 16QAM: The future of Optical Modulation

As we move into the 800G to 1.6T era, traditional modulation formats like QPSK and 16QAM are hitting their limits. To meet the growing demand for faster, more efficient optical networks, we need advanced formats.

Why Modulation Matters: Modulation encodes data onto light waves, balancing efficiency, reach, and power in optical systems.

Key factors:

  1. Spectral efficiency
  2. Reach (distance without regeneration)
  3. Noise tolerance (OSNR)
  4. Power consumption & DSP complexity

The Evolution:

  1. QPSK: Robust for long-haul, low spectral efficiency.
  2. 16QAM: Higher data rates but shorter reach due to noise sensitivity.
  3. Higher-order QAM (64QAM, 128QAM, 256QAM): Increased data capacity but increased noise sensitivity.

Next-Gen Techniques:

  1. Probabilistic Constellation Shaping (PCS): Optimizes symbol distribution for improved reach, noise tolerance, and bandwidth efficiency.
  2. Geometric Shaping (GS): Optimizes symbol placement for improved SNR and efficiency, especially in 800G+ systems.

Looking Ahead:

  1. AI-driven Adaptive Modulation: Real-time selection of the best modulation format.
  2. Orbital Angular Momentum (OAM): Potential ultra-high-capacity systems leveraging the twist of light.

Conclusion: To power future networks beyond 1.6T, advanced modulation formats like PCS, GS, and AI-driven approaches will drive efficiency and performance. Which modulation format do you think will dominate the future of optical communication? Let’s discuss in the comments!

PDF: :point_down:

Beyond QPSK and 16QAM - The future of Optical Modulation (By Jayvie Suriaga, PECE).pdf (2.2 MB)

LinkedIn: :point_down:

1 Like