Method for receiving optical orthogonal frequency-division multiplexing signal and receiver thereof

A receiver of an optical orthogonal frequency-division multiplexing (OFDM) system, adapted to receive an optical signal emitted by an emitter of the optical OFDM system, comprising:

• an optical-to-electrical converting element, for receiving and converting the optical signal into an analog signal;
• an analog-to-digital converting element, for converting the analog signal into a digital signal;
• a symbol boundary estimator, for estimating a symbol boundary according to the digital signal;
• a guard interval removal element, for removing a guard interval of the digital signal according to the symbol boundary, so as to generate a digital electrical signal;
• a fast Fourier transform (FFT) element, for converting the electrical signal into a plurality of frequency domain sub-carriers Y(k) in an FFT manner, wherein each of the frequency domain sub-carriers comprises a plurality of symbols, the symbols corresponding to the same frequency domain sub-carrier comprise a plurality of data carrier signals and pilot carrier signals, and the pilot carrier signals X(k) are located in the same symbol period, wherein k is an integer greater than or equal to −N/2 and smaller than (N/2)−1, and N is an FFT size;
• and
• a timing offset estimator, for estimating a timing offset τ with the pilot carrier signals X(k) and four frequency domain sub-carriers Y(k) corresponding to the same symbol period, wherein the symbol boundary estimator compensates and estimates the symbol boundary according to the timing offset.