A novel interpolation algorithm for pilot-assisted channel estimation in DDO-OFDM System

Pilot patterns and interpolation algorithms are of great importance to the performance of pilot-assisted channel estimation in optical OFDM systems. Traditionally a number of pilot tones are periodically inserted into the OFDM symbols for the estimation of the channel state, for instance, the least-square (LS) linear interpolation was a traditional approach to estimate the phase rotation of the subcarriers. In this paper, we present a novel interpolation algorithm with better performance than linear interpolation method while maintain similar complexity. Simulations in a 10 Gb/s direct detection optical OFDM (DDO-OFDM) system show that the algorithm greatly improves the constellation convergence.