Performance evaluation of four-level modified Manchester modulation format for high-speed optical transmission systems
A new multilevel modulation scheme centred on Manchester signalling known as four-level modified Manchester (4-MM) modulation format is envisioned and proven statistically for high-speed optical fibre transmission links. Similarly, the bit error rate (BER) assessment version has been developed for the envisioned 4-MM format. The performance of new 4-MM is examined and compared with conventional Manchester modulation, binary MM modulation, and four-level pulse amplitude modulation (4-PAM) formats in relation to receiver sensitivity, spectral efficiency, and chromatic dispersion tolerance. Therefore, the computed receiver sensitivity and chromatic dispersion tolerance at 10−9 BER of the envisioned 4-MM are −21.5 dBm and 95 ps/nm, respectively. The receiver sensitivity of 4-MM was improved by 3 dB in comparison with 4-PAM in a back-to-back configuration. Similarly, assessment of results indicates that 4-MM technique has a distinct benefit in comparison with binary MM and 4-PAM in achieving a dynamic role in the subsequent generation of high-speed optical access and short reach networks where power efficiency is of critical important.