Signal processing method, device, and system in a passive optical network

A signal processing method in a passive optical network, comprising:

• performing analog/digital conversion on received superposed optical domain Orthogonal Frequency Division Multiple Access signals;
• performing Orthogonal Frequency Division Multiplexing demodulation on the signals after analog/digital conversion;
• and
• performing baseband decoding processing on the signals after Orthogonal Frequency Division Multiplexing demodulation to obtain service signals.

An optical network unit, comprising:

• an encoding module, configured to perform baseband encoding processing on a received service signal;
• an Orthogonal Frequency Division Multiplexing modulation module, configured to modulate the signal after baseband encoding processing onto allocated Orthogonal Frequency Division Multiple Access subcarriers through an Orthogonal Frequency Division Multiplexing modulation manner;
• a digital/analog conversion module, configured to perform digital/analog conversion on the modulated Orthogonal Frequency Division Multiple Access subcarriers to obtain an electric domain Orthogonal Frequency Division Multiple Access signal;
• an optical modulation module, configured to modulate the electric domain Orthogonal Frequency Division Multiple Access signal to an uplink optical signal to obtain an optical domain Orthogonal Frequency Division Multiple Access signal;
• and
• a transmission module, configured to transmit the optical domain Orthogonal Frequency Division Multiple Access signal.

An optical line terminal, comprising:

• an analog/digital conversion module, configured to perform analog/digital conversion on received superposed Orthogonal Frequency Division Multiple Access signals;
• an Orthogonal Frequency Division Multiplexing demodulation module, configured to perform Orthogonal Frequency Division Multiplexing demodulation on the signals after analog/digital conversion;
• and
• a baseband decoding module, configured to perform baseband decoding processing on the signals after Orthogonal Frequency Division Multiplexing demodulation to obtain service signals.

A passive optical network system, comprising an optical line terminal, a remote node, and more than one optical network unit (ONU), wherein:

• the ONU is configured to perform baseband encoding processing on a received service signal;
• modulate the signal after baseband encoding processing onto allocated Orthogonal Frequency Division Multiple Access subcarriers through Orthogonal Frequency Division Multiplexing modulation;
• perform digital/analog conversion on the modulated Orthogonal Frequency Division Multiple Access subcarriers to obtain an electric domain Orthogonal Frequency Division Multiple Access signal;
• modulate the electric domain Orthogonal Frequency Division Multiple Access signal onto an uplink optical signal to obtain an optical domain Orthogonal Frequency Division Multiple Access signal;
• and transmit the optical domain Orthogonal Frequency Division Multiple Access signal;
• the remote node is configured to superpose optical domain Orthogonal Frequency Division Multiple Access signals of the same wavelength transmitted from different optical network units through a power splitter, multiplex the superposed optical domain Orthogonal Frequency Division Multiple Access signals into a multi-wavelength optical signal through a Wave Division Multiplexing multiplexer, and transmit the multi-wavelength optical signal to the optical line terminal;
• and
• the optical line terminal is configured to demultiplex the received multi-wavelength optical signal to obtain optical signals of different wavelengths, wherein the optical signals of different wavelengths bear the superposed optical domain Orthogonal Frequency Division Multiple Access signals, and perform analog/digital conversion, Orthogonal Frequency Division Multiplexing demodulation, and baseband decoding processing on the superposed optical domain Orthogonal Frequency Division Multiple Access signals respectively to obtain service signals.