Cyclic prefixed versus zero-padded-coherent optical OFDM systems' based MMSE equalization

This paper investigates the effects of zero padding and cyclic prefixing in channel equalization for coherent optical orthogonal frequency division multiplexing (CO-OFDM) system. Two equalization-based algorithms, namely zero forcing (ZF) and minimum mean square error (MMSE) based equalizers are employed for the system The computer simulation results show that the zero padded (ZP)-CO-OFDM system outperforms its counterpart, the CP-CO-OFDM system. These results indicate that the ZP-CO-OFDM system can mitigate effects of the fiber link such as chromatic dispersion and polarization mode dispersion better than the CP-CO-OFDM system. The results also show that the MMSE based equalizer only slightly outperforms the ZF-based equalizer, that has associated low computational complexity, in the ZP-CO-OFDM system.