PAM-4 delivery based on pre-distortion and CMMA equalization in a ROF system at 40Â GHz

In this paper, we proposed a PAM-4 delivery in a ROF system at 40-GHz. PAM-4 transmission data can be generated via look-up table (LUT) pre-distortion, then delivered over 25km single-mode fiber and 0.5m wireless link. At the receiver side, the received signal can be processed with cascaded multi-module algorithm (CMMA) equalization to improve the decision precision. Our measured results show that 10Gbaud PAM-4 transmission in a ROF system at 40-GHz can be achieved with BER of 1.6 × 10−3. To our knowledge, this is the first time to introduce LUT pre-distortion and CMMA equalization in a ROF system to improve signal performance.