Apparatus for measuring a filtering characteristic, pre-equalizer and communication equipment

Patent metadata

Field	Value
Publication number	US-10116388-B2
Application number	US-201615375714-A
Country	US
Kind code	B2
Filing date	Dec 12, 2016
Priority date	Dec 11, 2015
Publication date	Oct 30, 2018
Grant date	Oct 30, 2018

Abstract

A method and apparatus for measuring a filtering characteristic, pre-equalizer and communication equipment. The method includes: obtaining a receiving signal after two measurement signals of different spectral ranges pass through different filtering modules and are received at the same time at a receiving end; and determining a part of a filtering characteristic of a receiving end and a part of a joint response according to a nonoverlapped spectral part of the two signals in the spectrum of the receiving signal.

First claim

What is claimed is:

1. An apparatus for measuring a filtering characteristic, including:
processor circuitry configured to:
one of determine a first part of a filtering characteristic of a receiving end and determine a first part of a joint response of the filtering characteristic of a transmitting end and the filtering characteristic of the receiving end, in a spectrum of a first receiving signal obtained after a first measurement signal and a second measurement signal pass through respective filtering modules, according to a nonoverlapped spectral part of the first measurement signal and the second measurement signal;
one of determine a second part of the filtering characteristic of the receiving end in a spectrum of a second receiving signal obtained after a third measurement signal and the second measurement signal pass through respective filtering modules, according to a nonoverlapped spectral part of the third measurement signal and the second measurement signal and determine a second part of the joint response of the filtering characteristic of the transmitting end and the filtering characteristic of the receiving end, in the spectrum of the second receiving signal obtained after a fourth measurement signal and the first measurement signal pass through respective filtering modules, according to a nonoverlapped spectral part of the fourth measurement signal and the first measurement signal; and
one of determine the filtering characteristic of the receiving end according to the first part of the filtering characteristic and the second part of the filtering characteristic and determine the joint response of the filtering characteristic of the transmitting end and the filtering characteristic of the receiving end according to the first part of the joint response and the second part of the joint response;
wherein, the filtering modules through which the first measurement signal and the third measurement signal pass include a transmitting end filtering module and a receiving end filtering module, a filtering module through which the second measurement signal and the fourth measurement signal pass include the transmitting end filtering module, spectral ranges of the first measurement signal and the second measurement signal are different, and one of frequencies of the third measurement signal and the first measurement signal are complementary and frequencies of the fourth measurement signal and the second measurement signal are complementary;
and frequency complementarity denotes that spectral ranges of two measurement signals cover all a measurement range of the filtering characteristic, and the two measurement signals have an overlapped frequency point; and the first measurement signal, the second measurement signal, the third measurement signal and the fourth measurement signal are continuous signals.

2. The apparatus according to claim 1 , wherein the processor circuitry configured to:
calculate a first receiving signal power spectral density of the first receiving signal;
extract a first power spectral density of the nonoverlapped spectral part of the first measurement signal and the second measurement signal from the spectrum of the first receiving signal power spectral density of the first receiving signal; and
obtain the first part of the filtering characteristic of the receiving end according to the first power spectral density; and
calculate a second receiving signal power spectral density of the second receiving signal;
extract a second power spectral density of the nonoverlapped spectral part of the third measurement signal and the second measurement signal from the spectrum of the power spectral density of the second receiving signal; and
obtain the second part of the filtering characteristic of the receiving end according to the second receiving signal second power spectral density.

3. The apparatus according to claim 1 , wherein the processor circuitry configured to:
judge whether responses of the first part of the filtering characteristic and the second part of the filtering characteristic are identical at the overlapped frequency point; and
combine the first part of the filtering characteristic and the second part of the filtering characteristic when a result of judgment is responses of the first part of the filtering characteristic and the second part of the filtering characteristic are identical at the overlapped frequency point to obtain a consecutive filtering characteristic;
and when the result of judgment is responses of the first part of the filtering characteristic and the second part of the filtering characteristic are not identical at the overlapped frequency points, the processor circuitry further configured to:
adjust the responses of the first part of the filtering characteristic and the second part of the filtering characteristic at the overlapped frequency point to be identical; and
combine an adjusted first part of the filtering characteristic and second part of the filtering characteristic to obtain the consecutive filtering characteristic.

4. The apparatus according to claim 2 , wherein
the processor circuitry further configured to:
remove a second measurement signal power spectral density of the second measurement signal from the first power spectral density when the second measurement signal has a non flat power spectral density; and
determine the first part of the filtering characteristic according to a result of processing; and
remove the second measurement signal power spectral density of the second measurement signal from the second power spectral density extracted when the second measurement signal has the non flat power spectral density; and
determine the second part of the filtering characteristic according to the result of processing.

5. The apparatus according to claim 2 , wherein the processor circuitry further configured to:
determine the first part of the joint response according to an overlapped spectral part of the first measurement signal and the second measurement signal in the spectrum of the power spectral density of the first receiving signal;
determine the second part of the joint response according to the overlapped spectral part of the third measurement signal and the second measurement signal in the spectrum of the power spectral density of the second receiving signal; and
determine the joint response according to the first part of the joint response and the second part of the joint response.

6. The apparatus according to claim 5 , wherein the processor circuitry configured to:
extract a third power spectral density of the overlapped spectral part of the first measurement signal and the second measurement signal from the spectrum of the power spectral density of the first receiving signal; and
obtain the first part of the joint response according to the third power spectral density; and
extract a fourth power spectral density of the overlapped spectral part of the third measurement signal and the second measurement signal from the spectrum of the power spectral density of the second receiving signal; and
obtain the second part of the joint response according to the fourth power spectral density.

7. The apparatus according to claim 5 , wherein the processor circuitry configured to:
judge whether responses of the first part of the joint response and the second part of the joint response are identical at the overlapped frequency point; and
combine the first part of the joint response and the second part of the joint response when a result of judgment is responses of the first part of the joint response and the second part of the joint response are identical at the overlapped frequency point to obtain the consecutive joint response; and
when the result of judgment is responses of the fir

Assignees

• Fujitsu Ltd

Inventors

• Fan Yangyang
• Tao Zhenning
• Dou Liang

Classifications

• H04L25/03878

  Line equalisers; line build-out devices · CPC title

• H04L25/022 Primary

  of frequency response · CPC title

• H04B10/0779

  Monitoring line transmitter or line receiver equipment · CPC title

• H04B10/0731

  Testing or characterisation of optical devices, e.g. amplifiers · CPC title

• H04B10/25073 Primary

  using spectral equalisation, e.g. spectral filtering · CPC title