Fig. 1. Cascaded DDLMS. (a) Diagram of DDLMS flow; (b) structure of cascaded DDLMS

Fig. 2. Simulation system of optical transmission

Fig. 3. Diagram of DSP algorithm flow

Fig. 4. Simulation results of three DSP schemes. (a) IQ amplitude imbalance of Tx; (b) IQ phase imbalance of Tx; (c) IQ time skew of Tx

Fig. 5. Error of transceiver joint estimation. (a)(d) IQ amplitude imbalance; (b)(e) IQ phase imbalance; (c)(f) IQ time skew