OCDM-SDM Optical Communication System Utilizing Four-Dimensional Constellation Mapping

In this article, an orthogonal chirp division multiplexing (OCDM) Space division multiplexing (SDM) optical communication utilizing four-dimensional constellation mapping is proposed. A new 16-point four-dimensional constellation is designed, and its constellation figure of merit (CFM) can reach 1.17. A direct detection orthogonal chirp division multiplexing (DD-OCDM) transmission scheme based on four-dimensional constellation mapping is designed, and 32.8 Gb/s OCDM signal transmission is performed across 2 km seven core fiber through experiments, which verifies the performance of the proposed constellation. Under the condition of multi-core multiplexing and the bit error rate (BER) of 3.8 × 10
⁻³
, the receiver sensitivity of the OCDM signal, which is based on the proposed four-dimensional constellation mapping based on associated constellation mapping (16ACM-4D), has a gain of 0.59 dB, 3.26 dB, and 5.73 dB compared with the OCDM signals based on QPSK, 16QAM, and 16PSK, respectively. The results show that the proposed OCDM short-reach optical communication scheme based on four-dimensional constellation mapping has good bit error performance and anti-interference ability, and has broad application prospects in the future short-reach optical communication.