JP2982272B2 - Distortion monitor circuit - Google Patents
Distortion monitor circuitInfo
- Publication number
- JP2982272B2 JP2982272B2 JP2266705A JP26670590A JP2982272B2 JP 2982272 B2 JP2982272 B2 JP 2982272B2 JP 2266705 A JP2266705 A JP 2266705A JP 26670590 A JP26670590 A JP 26670590A JP 2982272 B2 JP2982272 B2 JP 2982272B2
- Authority
- JP
- Japan
- Prior art keywords
- distortion
- frequency
- monitor circuit
- filter
- division multiplexed
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R23/00—Arrangements for measuring frequencies; Arrangements for analysing frequency spectra
- G01R23/16—Spectrum analysis; Fourier analysis
- G01R23/20—Measurement of non-linear distortion
Landscapes
- Physics & Mathematics (AREA)
- Nonlinear Science (AREA)
- Mathematical Physics (AREA)
- General Physics & Mathematics (AREA)
- Monitoring And Testing Of Transmission In General (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は周波数分割多重信号の歪みモニタ回路に関
し、特に非直線性によって生じる歪み雑音の発生状況を
モニタする歪みモニタ回路に関する 〔従来の技術〕 一般に、複数のチャネルからなる周波数分割多重信号
を扱う伝送システムにおいては、信号経路の非直線性に
より歪み雑音が生じて信号の伝送品質が劣化する。従
来、端局を含む伝送路においてこのような歪み雑音の発
生状況を常時モニタ回路できる機能を有する伝送システ
ムはなかった。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distortion monitor circuit for a frequency division multiplexed signal, and more particularly to a distortion monitor circuit for monitoring a state of occurrence of distortion noise caused by non-linearity. In general, in a transmission system that handles a frequency division multiplexed signal composed of a plurality of channels, distortion noise is generated due to non-linearity of a signal path, and signal transmission quality is degraded. Conventionally, there has been no transmission system having a function of constantly monitoring a state of occurrence of such distortion noise in a transmission line including a terminal station.
本発明の目的は、非直線性による歪み雑音の発生状況
を常時モニタできる歪みモニタ回路を提供することにあ
る。SUMMARY OF THE INVENTION It is an object of the present invention to provide a distortion monitor circuit capable of constantly monitoring the state of occurrence of distortion noise due to non-linearity.
本発明の歪みモニタ回路は、各チャネルの中心周波数
の間隔がf0且つチャネルの最低中心周波数が2f0以上の
周波数分割多重信号における非直接性による歪み雑音を
モニタする歪みモニタ回路において、前記周波数分割多
重信号の占有帯域の最低周波数までの領域に発生する所
定の信号成分を取り出すフィルタと、このフィルタの出
力を所定のレベルに増幅する増幅器と、この増幅器の出
力を検波する第１の検波器と、前記周波数分割多重信号
を検波する第２の検波器と、前記第１および第２の検波
器の各出力の差を出力する差動増幅器とを備えて構成さ
れている。また、前記フィルタは、中心周波数f0で帯域
幅f0以内の周波数成分を取り出す帯域フィルタで構成し
てもよい。The distortion monitor circuit of the present invention is a distortion monitor circuit for monitoring distortion noise due to indirectness in a frequency division multiplexed signal in which the center frequency interval of each channel is f 0 and the minimum center frequency of the channel is 2f 0 or more. A filter for extracting a predetermined signal component generated in a region up to the lowest frequency of the occupied band of the division multiplex signal, an amplifier for amplifying the output of the filter to a predetermined level, and a first detector for detecting the output of the amplifier A second detector for detecting the frequency division multiplexed signal; and a differential amplifier for outputting a difference between respective outputs of the first and second detectors. Further, the filter is at the center frequency f 0 may be constituted by a band filter for extracting a frequency component within the bandwidth f 0.
一般に、複数の信号からなる周波数分割多重信号に
は、信号経路の非直線性によって歪み雑音が生じる。こ
の場合、任意の２つの信号の２次歪み、すなわち、２つ
の信号の和差ビート成分は他の歪み成分に比してレベル
が大きい。いま、各チャネルの中心周波数の間隔をf0と
し、チャネルの最低中心周波数f1を2f0とすると、第３
図に示すように非直線性によって、周波数f0を中心に和
差ビート成分が発生する。この和差ビート成分をモニタ
回路することにより、非直線性による歪み雑音の発生状
況を推測することができる。In general, distortion noise is generated in a frequency division multiplexed signal composed of a plurality of signals due to nonlinearity of a signal path. In this case, the secondary distortion of any two signals, that is, the sum difference beat component of the two signals has a higher level than the other distortion components. Now, the distance between the center frequency of each channel and f 0, when the lowest center frequency f1 of the channel and 2f 0, 3
Nonlinearities as illustrated in FIG, Wasa beat component is generated around the frequency f 0. By monitoring this sum difference beat component, it is possible to estimate the state of occurrence of distortion noise due to nonlinearity.
第１図は本発明の一実施例を示すブロック図であり、
中心周波数f0で帯域幅f0以内の周波数成分を取り出す帯
域フィルタ11と、帯域フィルタ11の出力を増幅する増幅
器12と、検波器13および14と、差動増幅器15とを備えて
いる。帯域フィルタ11は、中心周波数f0で所定の帯域幅
の周波数成分を取出す。増幅器12は、帯域フィルタ11に
よって減衰して取出された所定の周波数成分を減衰前の
レベルになるように増幅する。検波器13は所定の周波数
成分を検波する。さて、周波数分割多重信号Siを帯域フ
ィルタ11に入力して所定の周波数成分のみを通過させ、
増幅器12により増幅した後、検波器13によって検波して
所定の周波数成分の検波出力L1を得る。この検波出力L1
が歪み雑音のレベルをを示している。また、周波数分割
多重信号Siをを検波器14で検波して周波数分割多重信号
Siの検出力L2を得る。この検波出力L1およびL2を差動増
幅器15に入力することにより、波数分割多重信号Siのチ
ャネル数に依存しない歪み雑音の相対値を得ることがで
きる。この相対値を歪みモニタ出力Smとすることによ
り、非直線性による歪み雑音の発生状況をモニタでき
る。FIG. 1 is a block diagram showing one embodiment of the present invention.
A bandpass filter 11 for taking out the frequency components within the bandwidth f 0 at the center frequency f 0, an amplifier 12 for amplifying the output of the bandpass filter 11, a detector 13 and 14, and a differential amplifier 15. Bandpass filter 11 extracts the frequency component of a predetermined bandwidth at the center frequency f 0. The amplifier 12 amplifies the predetermined frequency component attenuated and extracted by the bandpass filter 11 to a level before the attenuation. The detector 13 detects a predetermined frequency component. Now, the frequency division multiplexed signal Si is input to the bandpass filter 11 to pass only predetermined frequency components,
After amplification by the amplifier 12, detection is performed by the detector 13 to obtain a detection output L1 of a predetermined frequency component. This detection output L1
Indicates the level of distortion noise. Further, the frequency division multiplexed signal Si is detected by the detector 14 and the frequency division multiplexed signal Si is detected.
The detection power L2 of Si is obtained. By inputting the detection outputs L1 and L2 to the differential amplifier 15, a relative value of distortion noise independent of the number of channels of the wave number division multiplexed signal Si can be obtained. By using this relative value as the distortion monitor output Sm, it is possible to monitor the occurrence of distortion noise due to nonlinearity.
第２図は第１図に示した歪みモニタ回路を光送信装置
に応用した一実施例を示すブロック図であり、周波数分
割多重信号Siに応じて光変調を行う発光素子21における
歪み雑音の発生状況をモニタする場合を示している。こ
の場合、発光素子21の出力光を受光素子22で光−電気変
換し、更に、増幅器23で所定のレベルに増幅した後、入
力する周波数分割多重信号Siと共に歪みモニタ回路10に
供給して歪みモニタ出力Smを得ている。ここで、増幅器
24は発光素子21を周波数分割多重信号Siに応じて駆動す
るための増幅器である。なお、この歪みモニタ回路10を
光受信装置側にも設けることにより、光送信装置および
光受信装置を含めた光伝送システムの非直線性による歪
み雑音の発生状況をモニタすることができる。FIG. 2 is a block diagram showing an embodiment in which the distortion monitor circuit shown in FIG. 1 is applied to an optical transmission device, and the generation of distortion noise in a light emitting element 21 that performs optical modulation according to a frequency division multiplexed signal Si. The case where the situation is monitored is shown. In this case, the output light of the light emitting element 21 is subjected to photoelectric conversion by the light receiving element 22, further amplified to a predetermined level by the amplifier 23, and then supplied to the distortion monitor circuit 10 together with the input frequency division multiplexed signal Si to be subjected to distortion. Monitor output Sm is obtained. Where the amplifier
An amplifier 24 drives the light emitting element 21 according to the frequency division multiplexed signal Si. By providing the distortion monitor circuit 10 also on the optical receiving device side, it is possible to monitor the occurrence of distortion noise due to the non-linearity of the optical transmission system including the optical transmitting device and the optical receiving device.
以上説明したように本発明は、各チャネルの中心周波
数の間隔がf0且つチャネルの最低中心周波数が2f0以上
の周波数分割多重信号において、伝送経路の非直線性に
よって周波数多重信号の占有帯域の最低周波数までの領
域に発生する所定の信号成分をフィルタにより取り出
し、この所定の信号成分を増幅後検波した検波出力レベ
ルと周波数多重信号の検波出力レベルとの差をモニタす
ることにより、非直線性による歪み雑音の発生状況を常
時モニタできる。The present invention as described above, the distance of the center frequency of each channel at the lowest center frequency 2f 0 or more frequency division multiplexed signal f 0 and channel, the band occupied by the frequency division multiplexed signal by the non-linearity of the transmission path By filtering out a predetermined signal component generated in the region up to the lowest frequency and amplifying the predetermined signal component and monitoring the difference between the detection output level of the frequency multiplexed signal and the non-linearity, Can constantly monitor the occurrence of distortion noise.
第１図は本発明の一実施例を示すブロック図、第２図は
第１図に示した歪みモニタ回路を光送信装置に応用した
一実施例を示すブロック図、第３図は周波数分割多重信
号を示す図である。 10……歪みモニタ回路、11……帯域フィルタ、12,23,24
……増幅器、13,14……検波器、15……差動増幅器、21
……発光素子、22……受光素子、Si……周波数分割多重
信号、Sm……歪みモニタ出力。FIG. 1 is a block diagram showing one embodiment of the present invention, FIG. 2 is a block diagram showing one embodiment in which the distortion monitor circuit shown in FIG. 1 is applied to an optical transmitter, and FIG. 3 is frequency division multiplexing. It is a figure showing a signal. 10 …… Distortion monitor circuit, 11 …… Band filter, 12,23,24
…… Amplifier, 13,14 …… Detector, 15 …… Differential amplifier, 21
... Light-emitting element, 22 ... Light-receiving element, Si ... Frequency division multiplexed signal, Sm ... Distortion monitor output.
フロントページの続き (58)調査した分野(Int.Cl.6，ＤＢ名) H04B 3/46 - 3/48 H04B 17/00 H04B 1/02 - 1/60 H04J 1/00 H04B 10/00 Continuation of the front page (58) Field surveyed (Int. Cl. 6 , DB name) H04B 3/46-3/48 H04B 17/00 H04B 1/02-1/60 H04J 1/00 H04B 10/00
Claims (2)
ャネルの最低中心周波数が2f0以上の周波数分割多重信
号における非直線性による歪み雑音をモニタする歪みモ
ニタ回路において、前記周波数分割多重信号の占有帯域
の最低周波数までの領域に発生する所定の信号成分を取
り出すフィルタと、このフィルタの出力を所定のレベル
に増幅する増幅器と、この増幅器の出力を検波する第１
の検波器と、前記周波数分割多重信号を検波する第２の
検波器と、前記第１および第２の検波器の各出力の差を
出力する差動増幅器とを備えたことを特徴とする歪みモ
ニタ回路。1. A distortion monitor circuit for monitoring distortion noise due to non-linearity in a frequency division multiplexed signal having a center frequency interval of each channel of f 0 and a minimum center frequency of the channel of 2f 0 or more, A filter for extracting a predetermined signal component generated in a region up to the lowest frequency of the occupied band, an amplifier for amplifying the output of the filter to a predetermined level, and a first for detecting the output of the amplifier.
And a second detector for detecting the frequency division multiplexed signal, and a differential amplifier for outputting a difference between outputs of the first and second detectors. Monitor circuit.
以内の周波数成分を取り出す帯域フィルタであることを
特徴とする請求項１記載の歪みモニタ回路2. The filter according to claim 1, wherein said filter has a bandwidth f 0 at a center frequency f 0.
2. The distortion monitor circuit according to claim 1, wherein the distortion monitor circuit is a bandpass filter for extracting a frequency component within a range.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2266705A JP2982272B2 (en) | 1990-10-04 | 1990-10-04 | Distortion monitor circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2266705A JP2982272B2 (en) | 1990-10-04 | 1990-10-04 | Distortion monitor circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH04143670A JPH04143670A (en) | 1992-05-18 |
| JP2982272B2 true JP2982272B2 (en) | 1999-11-22 |
Family
ID=17434541
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2266705A Expired - Lifetime JP2982272B2 (en) | 1990-10-04 | 1990-10-04 | Distortion monitor circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2982272B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105093153A (en) * | 2015-08-18 | 2015-11-25 | 国网辽宁省电力有限公司大连供电公司 | Evaluation method for measurement nonlinearity of fundamental wave frequency reactive power |
-
1990
- 1990-10-04 JP JP2266705A patent/JP2982272B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH04143670A (en) | 1992-05-18 |
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