A modulation scheme for 100 Gb/s modified minimum-shift keying format based on imbalanced bias in IQ components

We propose a modified minimum-shift keying (MSK) modulation scheme by applying the imbalanced bias on the in-phase and quadrature components of a MZM-based MSK modulator. This scheme enables constant envelope and continuous temporal phase shift of 100 Gb/s optical MSK signal by driving the MZMs with traditional sinusoidal signal instead of triangle signal. The principle of generating the optical MSK signal by this imbalanced scheme is presented. Theoretical analysis is given to modulated spectra, BER performance, residual dispersion tolerance and SPM tolerance. It is demonstrated that compared to the existing solutions the proposed scheme is able to decrease 2 dB receiver power penalty and improve SPM tolerance by 2 dB.

► A 100 Gb/s MSK signal with constant envelope and continuous temporal phase shift. ► Using traditional sinusoidal signal to drive the MZMs instead of triangle signal. ► Generation principle, equations, and pre-coding logic circuit based on the system. ► Outperform the existing schemes by 2 dB receiver power penalty. ► Comparing with existing schemes, improve the SPM tolerance by 1–2 dB.