SSBI-free SSB-DD transmission scheme using phase modulation for high-quality analog mobile fronthaul

摘要

In this invited talk, we introduce a signal-to-signal beat interference (SSBI)-free direct-detection transmission system using phase modulation (PM), which was proposed and presented in the ECOC2019 post-deadline session. In the scheme, a PM signal is detected by single photodiode as self- heterodyne detection. Since the PM signal has a constant envelope, the SSBI term becomes just a DC component. Therefore, SSBI can be easily removed by a DC block without using any complicated schemes such as the Kramers-Kronig (KK) algorithm. In addition, the optimal carrier-to-signal-power-ratio (CSPR) value is always found to be 0 dB, which can improve the power efficiency compared to the KK scheme. By using the SSBI-free scheme, we could successfully transmit a 2-GHz 1024QAM OFDM signal.