Signal processing method, apparatus, and optical fiber transmission system

Patent metadata

Field	Value
Publication number	US-10673534-B2
Application number	US-201916425954-A
Country	US
Kind code	B2
Filing date	May 30, 2019
Priority date	Nov 30, 2016
Publication date	Jun 2, 2020
Grant date	Jun 2, 2020

Abstract

A signal processing method is provided. Under the method, a first digital signal can be obtained by an optical transmitter. The first digital signal is a one-dimensional bipolar digital signal. A spectral compression and filtering can be performed by the optical transmitter on the first digital signal to generate a second digital signal. A frequency shift can be performed by the optical transmitter on the second digital signal such that a center location of a spectrum of the frequency-shifted second digital signal is at a frequency of 0.

First claim

What is claimed is:

1. A signal processing method, comprising:
obtaining, by an optical transmitter, a first digital signal, wherein the first digital signal is a one-dimensional bipolar digital signal;
performing, by the optical transmitter, spectral compression and filtering on the first digital signal to generate a second digital signal; and
performing, by the optical transmitter, frequency shift on the second digital signal, wherein a center location of a spectrum of the frequency-shifted second digital signal is at a frequency of 0.

2. The signal processing method according to claim 1 , wherein obtaining, by the optical transmitter, the first digital signal comprises:
obtaining, by the optical transmitter, a random sequence, and mapping, by the optical transmitter, the random sequence to generate the first digital signal.

3. The signal processing method according to claim 1 , wherein performing, by the optical transmitter, the spectral compression and filtering on the first digital signal to generate a second digital signal comprises:
performing, by the optical transmitter, spectral compression on the first digital signal to generate a third digital signal, wherein a spectral bandwidth of the third digital signal is less than a spectral bandwidth of the first digital signal; and
filtering, by the optical transmitter, the third digital signal to generate the second digital signal, wherein the second digital signal is a positive spectral part or a negative spectral part of the third digital signal.

4. The signal processing method according to claim 1 , wherein after performing, by the optical transmitter, the frequency shift on the second digital signal, the method further comprises:
resampling, by the optical transmitter, the second digital signal, and transmitting the second digital signal after the resampling to an optical receiver.

5. The signal processing method according to claim 1 , wherein the spectrum of the second digital signal further comprises a carrier.

6. A signal processing method, comprising:
performing, by an optical receiver, frequency shift on a second digital signal, wherein a spectral edge of the second digital signal after the frequency shift is at a frequency of 0; and
recovering, by the optical receiver, the second digital signal after the frequency shift to generate a first digital signal, wherein the first digital signal is a one-dimensional bipolar digital signal.

7. The signal processing method according to claim 6 , wherein recovering, by the optical receiver, the second digital signal after the frequency shift to generate the first digital signal comprises:
performing, by the optical receiver, filtering recovery on the second digital signal after the frequency shift, to generate a third digital signal, wherein the second digital signal is a positive spectral part or a negative spectral part of the third digital signal; and
performing, by the optical receiver, spectral compression recovery on the third digital signal, to generate the first digital signal, wherein a spectral bandwidth of the third digital signal is less than a spectral bandwidth of the first digital signal.

8. The signal processing method according to claim 6 , wherein before the performing, by an optical receiver, frequency shift on a second digital signal, the method further comprises:
receiving, by the optical receiver, the second digital signal transmitted by an optical transmitter, and resampling, by the optical receiver, the second digital signal.

9. The signal processing method according to claim 6 , wherein the spectrum of the second digital signal further comprises a carrier.

10. An optical transmitter, wherein the optical transmitter comprises a processor, wherein
the processor is configured to: obtain a first digital signal, wherein the first digital signal is a one-dimensional bipolar digital signal; perform spectral compression and filtering on the first digital signal to generate a second digital signal; and perform frequency shift on the second digital signal, wherein a center location of a spectrum of the frequency-shifted second digital signal is at a frequency of 0.

11. The optical transmitter according to claim 10 , wherein
the processor is configured to: obtain a random sequence, and map the random sequence to generate the first digital signal.

12. The optical transmitter according to claim 10 , wherein
the processor is configured to: perform spectral compression on the first digital signal to generate a third digital signal, wherein a spectral bandwidth of the third digital signal is less than a spectral bandwidth of the first digital signal; and perform filtering on the third digital signal to generate the second digital signal, wherein the second digital signal is a positive spectral part or a negative spectral part of the third digital signal.

13. The optical transmitter according to claim 10 , wherein the optical transmitter further comprises a transmitter;
the processor is further configured to resample the second digital signal after performing frequency shift on the second digital signal; and
the transmitter is configured to: after the processor resamples the second digital signal, transmit the resampled second digital signal to an optical receiver.

14. The optical transmitter according to claim 10 , wherein the spectrum of the second digital signal further comprises a carrier.

Assignees

• Huawei Tech Co Ltd

Inventors

• Lu Yanzhao
• Huang Yuanda

Classifications

• H04B10/5563 Primary

  Digital frequency modulation · CPC title

• H04B10/60

  Receivers · CPC title

• H04N21/61

  Network physical structure; Signal processing (H04B takes precedence) · CPC title

• H04B10/25

  Arrangements specific to fibre transmission · CPC title

• H04B1/68

  for wholly or partially suppressing the carrier or one side band · CPC title