Signal pre-compensation method and apparatus

1. A signal pre-compensation method, wherein the method is applied to an optical signal sending device, and comprises:

determining a target frequency subband from a plurality of frequency subbands, wherein the plurality of frequency subbands are frequency subbands in a frequency band of a first optical signal generated by the optical signal sending device;

demodulating an optical signal of the target frequency subband in the first optical signal based on the target frequency subband, and obtaining a first electrical signal after demodulation;

updating a pre-compensation parameter based on the target frequency subband, the first electrical signal, and a second electrical signal, wherein the pre-compensation parameter is used to perform signal pre-compensation on the second electrical signal;

generating the first optical signal after the pre-compensation is performed on the second electrical signal; and

wherein the target frequency subband comprises a plurality of target frequency subbands, the plurality of target frequency subbands are in a one-to-one correspondence with a plurality of first electrical signals, and each first electrical signal is obtained after an optical signal of a corresponding target frequency subband is demodulated.

2. The method according to claim 1 , wherein the demodulating an optical signal of the target frequency subband in the first optical signal based on the target frequency subband comprises:

generating at least one local oscillator signal based on the target frequency subband, wherein the target frequency subband is in a one-to-one correspondence with the at least one local oscillator signal, and a deviation between a center frequency of each local oscillator signal and a center frequency of a corresponding target frequency subband falls within a first preset range; and

demodulating the first optical signal based on the at least one local oscillator signal and a first demodulation bandwidth, wherein the first demodulation bandwidth is greater than or equal to a frequency bandwidth of the target frequency subband.

3. The method according to claim 1 , wherein the updating a pre-compensation parameter based on the target frequency subband, the first electrical signal, and a second electrical signal comprises:

determining a first symbol subsequence from a symbol sequence of the second electrical signal based on the target frequency subband, wherein a position of the first symbol subsequence in the symbol sequence of the second electrical signal is a first position, a position of the target frequency subband in the plurality of frequency subbands is a second position, and a deviation between the first position and the second position falls within a second preset range; and

updating the pre-compensation parameter based on a difference between a symbol sequence of the first electrical signal and the first symbol subsequence.

4. The method according to claim 3 , wherein the updating the pre-compensation parameter based on a difference between a symbol sequence of the first electrical signal and the first symbol subsequence comprises:

determining a first weight based on the frequency band position of the target frequency subband in the plurality of frequency subbands; and

updating the pre-compensation parameter based on the first weight and the difference between the symbol sequence of the first electrical signal and the first symbol subsequence.

5. The method according to claim 1 , wherein the plurality of frequency subbands have a same frequency bandwidth.

6. The method according to claim 1 , wherein the plurality of target frequency subbands are selected from the plurality of frequency subbands at an equal frequency band interval.

7. The method according to claim 6 , wherein the frequency band interval is one frequency subband.

8. A signal pre-compensation apparatus, comprising: a computing hardware; and

a computer-readable storage medium including computer-executable instructions executed by the computing hardware to perform operations comprising:

determining a target frequency subband from a plurality of frequency subbands, wherein the plurality of frequency subbands are frequency subbands in a frequency band of the optical signal sending device;

demodulating an optical signal of the target frequency subband in the first optical signal based on the target frequency subband, and obtaining a first electrical signal after demodulation;

updating a pre-compensation parameter based on the target frequency subband, the first electrical signal, and a second electrical signal, wherein the pre-compensation parameter is used to perform signal pre-compensation on the second electrical signal;

generating the first optical signal after the pre-compensation is performed on the second electrical signal; and

wherein the target frequency subband comprises a plurality of target frequency subbands, the plurality of target frequency subbands are in a one-to-one correspondence with a plurality of first electrical signals, and each first electrical signal is obtained after an optical signal of a corresponding target frequency subband is demodulated.

9. The apparatus according to claim 8 , wherein the computing hardware is configured with computer-executable instructions to perform operations such that the demodulating an optical signal of the target frequency subband in the first optical signal based on the target frequency subband comprises:

generating at least one local oscillator signal based on the target frequency subband, wherein the target frequency subband is in a one-to-one correspondence with the at least one local oscillator signal, and a deviation between a center frequency of each local oscillator signal and a center frequency of a corresponding target frequency subband falls within a first preset range; and

demodulating the first optical signal based on the at least one local oscillator signal and a first demodulation bandwidth, wherein the first demodulation bandwidth is greater than or equal to a frequency bandwidth of the target frequency subband.

10. The apparatus according to claim 8 , wherein the updating a pre-compensation parameter based on the target frequency subband, the first electrical signal, and a second electrical signal comprises:

determining a first symbol subsequence from a symbol sequence of the second electrical signal based on the target frequency subband, wherein a position of the first symbol subsequence in the symbol sequence of the second electrical signal is a first position, a position of the target frequency subband in the plurality of frequency subbands is a second position, and a deviation between the first position and the second position falls within a second preset range; and

updating the pre-compensation parameter based on a difference between a symbol sequence of the first electrical signal and the first symbol subsequence.

11. The apparatus according to claim 10 , wherein the updating the pre-compensation parameter based on a difference between a symbol sequence of the first electrical signal and the first symbol subsequence comprises:

determining a first weight based on the frequency band position of the target frequency subband in the plurality of frequency subbands; and

updating the pre-compensation parameter based on the first weight and the difference between the symbol sequence of the first electrical signal and the first symbol subsequence.

12. The apparatus according to claim 8 , wherein the plurality of frequency subbands have a same frequency bandwidth.

13. The apparatus according to claim 8 , wherein the plurality of target frequency subbands are selected from the plurality of frequency subbands at an equal frequency band interval.

14. The apparatus according to claim 13 , wherein the frequency band interval is one frequency subband.

15. The apparatus according to claim 8 , wherein the signal pre-compensation apparatus is a chip.