Channel estimation based on interference cancellation method for FBMC-PON

Abstract

Based on the traditional orthogonal frequency division multiplexing passive optical network (OFDM-PON) system, filter bank multi-carrier passive optical network (FBMC-PON) eliminates the CP by introducing a synthesis filter, dramatically improving spectral efficiency when the number of symbols is sufficient in one transmission. Meanwhile, thanks to its excellent bit error rate (BER) performance, FBMC-PON becomes one of the significant alternatives to OFDM-PON. In previous practical cases, the interference approximation method (IAM) based channel estimation algorithm, which mainly enhances the power of training sequence, plays superior in FBMC-PON. However, the interference cancellation method (ICM) channel estimation method is a better choice due to the self-cancellation of imaginary interference, especially for short-distance optical fiber access channels. We analyze the four different training sequences and consider that in the short fiber channel of PON, it is more vital to suppress the imaginary interference rather than improve the training sequence’s power. The simulation results show that the BER performance of FBMC-PON based on our proposed ICM training sequence structure is one order of magnitude higher than that of OFDM-PON and half an order of magnitude higher than that of IAM in the case of 20 km fiber. Our proposed channel estimation algorithm only changes the structure of the training sequence and does not increase any additional computational complexity. As far as we know, ICM training sequence structure is verified in FBMC-PON by simulation for the first time. The results show that ICM is the optimal choice of the 4 kinds of training sequence structures. ICM training sequence structure has a very high application prospect in short reach FBMC-PON.