Channel estimation algorithm for interference suppression in IMDD–OQAM–OFDM transmission systems

• IAFA-CE consider the intrinsic interference and channel noise on OQAM–OFDM system.
• The algorithm can achieve high accuracy CE for combating the system noise.
• The 10 Gb/s IMDD–OQAM–OFDM system is set to validate the algorithm.
• The algorithm can greatly reduce EVM.
• IAFA-CE can achieve ~1.5 dB sensitivity improvement compared with IAM-C.

In this paper, we investigate the intrinsic interference caused by intra-symbol data and channel noise in the intensity-modulation direct-detection OQAM–OFDM (IMDD–OQAM–OFDM) system by theoretical derivation. Based on the analysis, we proposed and experimentally demonstrated a channel estimation algorithm with the combination of IAM-C and frequency-averaging method to combat the effect of these noises. Experimental results show that compared to the common channel estimation algorithms, our algorithm can greatly reduce the error vector magnitude (EVM) and achieve ~1.5 dB sensitivity improvement.