We propose a wide-range frequency offset estimation algorithm used in a direct detection orthogonal frequency division multiplexing passive optical network (DD-OFDM-PON) downstream system. Using this method, frequency offset is estimated according to the spectrum of the received DD-OFDM signal. The estimated frequency offset is used for frequency down-conversion in the digital domain to obtain the baseband OFDM signal. With this method, all data-bearing subcarriers should fall into the OFDM bandwidth after frequency down-conversion. The validity of the method is confirmed by an experiment with 20 Gb/s OFDM-PON downstream transmission.
© 2012 OSA
Original Manuscript: September 16, 2011
Revised Manuscript: May 25, 2012
Manuscript Accepted: June 1, 2012
Published: June 21, 2012
Longquan Chen, Yaojun Qiao, Yuan Zhao, and Yuefeng Ji, "Wide-Range Frequency Offset Estimation Method for a DD-OFDM-PON Downstream System," J. Opt. Commun. Netw. 4, 565-570 (2012)