Power-efficient adaptive bias layered optical OFDM (Orthogonal Frequency Division Multiplexing) method and system

The invention discloses a power-efficient self-adaptive bias layered optical OFDM (Orthogonal Frequency Division Multiplexing) method and system, and aims to improve the power efficiency of an ABLO-OFDM method, adopt a constellation expansion method, calculate the expansion probability of a QAM (Quadrature Amplitude Modulation) symbol real part and an imaginary part on a subcarrier, and select the condition that the sending optical power is minimum under the condition that the same bit error rate is realized. At the moment, the power efficiency of the ABLO-OFDM method is improved. According to the scheme, the subcarrier utilization rate is high, the bit error rate is low, the performance in the aspects of receiving complexity and processing time delay is excellent, and efficient power is achieved on the basis. According to the method, information transmission is carried out by adopting multiple layers of subcarriers, the utilization rate of the subcarriers is close to 100% along with the increase of the numbe