An orthogonal frequency division multiplexing (OFDM) interconnected transmission system employing joint modulation of variable-order constellation compression and probabilistic shaping is proposed in this paper. In the proposed system, constant composition distribution matcher (CCDM) is utilized to implement probabilistic shaping, and fixed symbol-level label method is adopted to achieve the constellation compression. The coded modulation schemes can be adjusted dynamically according to the diversified traffic requirement of the users, in a bid to enhance the network utilization and provide effective end-to-end services. So far, to the best of our knowledge, it is the first time that probabilistic shaping and constellation compression modulation have been simultaneously applied to an interconnection system to achieve real-time self-tuning of transmission performances. Moreover, experimental verifications are successfully carried out by setting up a 25 km intensity-modulation/direct-detection interconnection transmission system. The results show lower bit error rate with flexible coding capability, indicating a high-potential transmission solution for the future optical communication.
