In-band crosstalk-induced power penalties in various signal modulation formats

Area of Science:

• Optical communications
• Signal processing
• Telecommunications engineering

Background:

• In-band crosstalk significantly impacts optical signal quality.
• Accurate estimation of power penalty is crucial for system design.
• Different modulation formats exhibit varying crosstalk tolerance.

Purpose of the Study:

• To derive a simple equation for estimating in-band crosstalk-induced power penalty.
• To compare crosstalk penalties across various optical signal modulation formats.
• To validate the derived equation against experimental measurements.

Main Methods:

• Developed a novel equation considering symbol peak power and intersymbol distance.
• Incorporated crosstalk level and Q-value into the penalty estimation.
• Estimated and compared penalties for On-Off Keying (OOK), DQPSK, and Pulse Amplitude Modulation-4 (PAM-4) signals.

Main Results:

• The derived equation accurately estimates in-band crosstalk-induced power penalty.
• On-Off Keying (OOK) non-return-to-zero signals are 9 dB more tolerant to in-band crosstalk than PAM-4 signals.
• Estimated results show strong agreement with measured data.

Conclusions:

• The developed equation provides a straightforward method for assessing crosstalk impact.
• OOK signals offer superior resilience to in-band crosstalk compared to PAM-4.
• The findings are validated by experimental data, confirming the equation's utility.