Signal processing devices, systems and method, and signal transmission subsystem and system

A signal processing device, comprising:

• a second photoelectric conversion module, configured to receive a first optical signal of a preset frequency sent by a first optical path coupling device, convert the first optical signal into a first electrical signal to be processed, and send the first electrical signal to be processed to a first photoelectric conversion module, wherein the first optical signal is obtained by the first optical path coupling device from an optical signal transmission line;
• and
• the first photoelectric conversion module, configured to convert the first electric signal to be processed into a first optical signal to be processed, and send the first optical signal to be processed to a time synchronization device;
• wherein the first photoelectric conversion module is further configured to receive an optical signal to be sent that is sent by the time synchronization device, convert the optical signal to be sent into an electric signal to be sent, and transmit the electrical signal to be sent to the second photoelectric conversion module, wherein the optical signal to be sent is generated by the time synchronization device according to an initial electrical signal, and the initial electrical signal comprises a service signal and a time synchronization signal, causing that in a process of transmitting the time synchronization signal, the signal processing device does not need to extract the time synchronization signal from the service signal;
• the second photoelectric conversion module is further configured to convert the electrical signal to be sent into a second optical signal of a preset frequency, and send the second optical signal to a second optical path coupling device, causing the second optical path coupling device to couple the second optical signal to the optical signal transmission line for transmission;
• and
• a wavelength difference between the first optical signal and the second optical signal is less than or equal to a preset wavelength threshold.

A signal processing method, comprising:

• receiving an optical signal to be sent that is sent by a time synchronization device, wherein the optical signal to be sent is generated by the time synchronization device according to an initial electrical signal, and the initial electrical signal comprises a service signal and a time synchronization signal, and in a process of transmitting the time synchronization signal, the time synchronization signal does not need to be extracted from the service signal;
• converting the optical signal to be sent into an electrical signal to be sent;
• converting the electrical signal to be sent into a first optical signal of a preset frequency;
• and
• sending the first optical signal to a first optical path coupling device, causing the first optical path coupling device to couple the first optical signal to an optical signal transmission line for transmission.