Self-interference-tolerant Frequency Offset Estimation Technique for IM/DD-based OFDMA-PON Systems

A self-interference tolerant Carrier Frequency Offset (CFO) and Sampling Frequency Offset (SFO) estimation technique is described for compensation of these impairment effects in passive optical networks (PONs) using orthogonal frequency-division multiple access (OFDMA) with intensity modulation and direct detection (IM/DD). Self-interference is due to CFO and SFO, as well as due to decoding of partial sub bands. The algorithm estimates the channel impulse response (CIR) based on training symbols added to the data frames header and is simple to process. Simulation and measurement results are presented as a proof-of-concept, as well as an indication of the achievable performance in presence of these real-world impairment effects.