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Phase compensation device, phase compensation method and communication device

A phase compensation and phase difference technology, which is applied in the field of phase compensation devices, can solve the problems that phase changes cannot be removed cleanly, and achieve the effect of improving accuracy

Active Publication Date: 2021-04-16
NTT ELECTORNICS CORP +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0012] However, even if the phase noise compensation is performed using the existing technology, there is still a problem that the phase fluctuation cannot be completely removed and remains

Method used

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  • Phase compensation device, phase compensation method and communication device
  • Phase compensation device, phase compensation method and communication device
  • Phase compensation device, phase compensation method and communication device

Examples

Experimental program
Comparison scheme
Effect test

Embodiment approach 1

[0028] figure 1 It is a diagram showing the communication device according to Embodiment 1 of the present invention. The communication device is a digital correlation optical receiver that receives an optical signal transmitted from a transmitting side.

[0029] The local oscillator light source 1 (Local Oscillator) is a light source that oscillates laser light having the same frequency as the optical signal. However, there is a frequency difference between the frequency of the optical signal and the frequency of output light of the local oscillation light source 1 due to individual differences in the local oscillation light source 1 or the like.

[0030] The optical phase mixer 2 mixes the optical signal and the local light output from the local oscillation light source 1 to generate a set of mutually orthogonal optical signals. One of a group of optical signals is obtained by combining the optical signal and partial light, and is called an optical signal of an I (In-phase,...

Embodiment approach 2

[0039] image 3 It is a diagram showing a phase compensation device according to Embodiment 2 of the present invention. Figure 4 It is a diagram plotting the output signal of the symbol phase difference compensator on the constellation diagram. In addition, the constellation diagram is also called a signal space diagram, and is a diagram representing a digitally modulated signal on the complex plane.

[0040] The rotational folding unit 15 folds the signals of all quadrants into the first quadrant with respect to the output signal of the symbol phase difference compensation unit 6 . That is, the signal in the 1st quadrant remains unchanged, the signal in the 2nd quadrant is rotated by -π / 2, folded into the 1st quadrant, and the signal located in the 3rd quadrant is rotated by -π, folded into the 1st quadrant, and located in the 4th quadrant The signal of is rotated by +π / 2 (=-3π / 2), and folded to the first quadrant. Then, the provisional determination unit 12 and the phase...

Embodiment approach 3

[0050] Figure 8 is a diagram showing a phase compensation device according to Embodiment 3 of the present invention. The configuration up to the calculation of the complex signal by the multiplication unit 19 is the same as that of the second embodiment. The rotation angle calculation unit 22 calculates the rotation angle corresponding to the second phase difference ΔΦ from the complex signal. Then, after the averaging unit 20 takes the average of several symbols, it is expressed by the exponential expression unit 23 with an exponential expression EXPj(ΔΦ).

[0051] The phase difference compensation unit 14 multiplies the output signal of the symbol phase difference compensation unit 6 by the rotation angle represented by an exponential expression. Thereby, it is possible to compensate for phase variation with respect to an output signal with a residual amount of phase noise.

[0052] In addition, it is also possible to record the program for realizing the functions of the...

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Abstract

A symbol phase difference compensator (6) calculates a first phase difference between a known pattern extracted from a received signal and its true value, that is, a phase difference, and performs phase compensation for the received signal based on the first phase difference. A provisional determination unit (12) performs a provisional determination on the output signal of the symbol phase difference compensation unit (6), and obtains a phase estimation value. The phase difference acquisition unit (13) acquires a second phase difference between the phase of the output signal and the phase estimated value obtained by the tentative determination unit (12). A phase difference compensator (14) performs phase compensation for the output signal based on the second phase difference.

Description

technical field [0001] The present invention relates to a phase compensating device, a phase compensating method and a communication device for compensating phase variation in data communication. Background technique [0002] In correlated optical communication, a frequency offset (frequency error) as a frequency difference occurs between the frequency of a received signal and the frequency of a local oscillation light source. In addition, due to nonlinear optical effects, vibration of optical fibers, etc., phase fluctuations such as phase noise occur in the received signal. [0003] On the other hand, a technique has been proposed that detects a frequency error after raising an input signal to the nth power and removes a phase term (phase change due to modulation), and feeds it back to the input side to compensate for a frequency offset (for example, refer to Patent Document 1). However, the frequency offset can be compensated to a certain extent, but there will be a lot o...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H04L27/01H04B10/61H04L27/38
CPCH04B10/61H04L27/3836H04L2027/0024H04L27/01H04L27/38H04B10/615H04B10/6164H04B10/6165
Inventor 山崎悦史野内裕之大沼靖治高椋智大大山胜一武井和人富泽将人木坂由明吉田光辉中村政则
Owner NTT ELECTORNICS CORP