DE2948549C2 - Method for adaptive equalization of digital baseband signals - Google Patents
Method for adaptive equalization of digital baseband signalsInfo
- Publication number
- DE2948549C2 DE2948549C2 DE19792948549 DE2948549A DE2948549C2 DE 2948549 C2 DE2948549 C2 DE 2948549C2 DE 19792948549 DE19792948549 DE 19792948549 DE 2948549 A DE2948549 A DE 2948549A DE 2948549 C2 DE2948549 C2 DE 2948549C2
- Authority
- DE
- Germany
- Prior art keywords
- signal
- residual distortion
- filter
- measuring device
- equalization
- 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
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L25/00—Baseband systems
- H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
- H04L25/03—Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
- H04L25/03006—Arrangements for removing intersymbol interference
- H04L25/03012—Arrangements for removing intersymbol interference operating in the time domain
- H04L25/03019—Arrangements for removing intersymbol interference operating in the time domain adaptive, i.e. capable of adjustment during data reception
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
- Filters That Use Time-Delay Elements (AREA)
Description
[1] Bocker, P.: Datenübertragung. Berlin, Heidelberg, New York: Springer-Verlag, Band I 1976, S. 214-231, Band II 1977.S. 49-52.[1] Bocker, P .: data transfer. Berlin, Heidelberg, New York: Springer-Verlag, Volume I 1976, pp. 214-231, Volume II 1977 p. 49-52.
[2] Schmidt W.: An Automatic Adaptive Equalizer for Digital Data Transmission. 1978 IEEE International Symposium on Circuits and Systems Proceedings, New York, 1978, S. 436-440.[2] Schmidt W .: An Automatic Adaptive Equalizer for Digital Data Transmission. 1978 IEEE International Symposium on Circuits and Systems Proceedings, New York, 1978, pp. 436-440.
[3] Schmidt W.: Grundlagen für die Anwendung des Oi thogonalfilters zur Filterung und Formung von Signalen unter besonderer Berücksichtigung der Entzerrung von Datenübertragungskanälen. Dissertation Universität Kaiserslautern 1979.[3] Schmidt W .: Basics for the application of the orthogonal filter for filtering and shaping of Signals with special consideration of the equalization of data transmission channels. dissertation University of Kaiserslautern 1979.
Kritik des Standes der TechnikCriticism of the state of the art
Adaptive Entzerrer, die auf dem erstgenannten Prinzip basieren, benötigen am Empfangsort eine separate Synchronisation und funktionieren nur bei nicht zu starken Verzerrungen. Oft ist auch eine besonders Startprozedur für den Entzerrungsablauf notwendig. Darüber hinaus bereitet die Entzerrung sogenannter Vorschwinger zusätzliche Schwierigkeiten. Der auf dem zweiten Prinzip basierende adaptive Entzerrer benötigt keine separate Synchronisation und funktioniert auch bei starken Verzerrungen ohne besondere Startprozedur. Selbst Vorschwinger bereiten keine besonderen Schwierigkeiten. Der Nachteil dieses Entzerrers liegt in der komplizierten und teuren Fehlermeßeinrichtung.Adaptive equalizers, which are based on the first-mentioned principle, require one at the receiving location separate synchronization and only work if the distortion is not too strong. Often there is also one start procedure for the equalization process is particularly necessary. It also prepares the equalization so-called pre-swing additional difficulties. The adaptive one based on the second principle The equalizer does not require a separate synchronization and works without it even with strong distortions special start procedure. Even pre-swings do not cause any particular difficulties. The downside to this The equalizer resides in the complicated and expensive error measuring device.
Aufgabetask
Der Erfindung liegt die Aufgabe zugrunde, bei dem gattungsgemäßen Verfahren ein Prinzip für eine Fehlermeßeinrichtung zu finden, das die Vorzüge des oben genannten zweiten Prinzips besitzt, womöglich noch besser ist, das sich aber durch eine einfachere und billigere Realisierungsmöglichkeit auszeichnetThe invention is based on the object, in the generic method, a principle for a To find error measuring device that has the advantages of the above-mentioned second principle, possibly is even better, but it is characterized by a simpler and cheaper implementation option
Lösungsolution
Diese Aufgabe wird erfinclungsgemäß dadurch gelöst daß als Fehlerkriterium der QuotientAccording to the invention, this object is achieved in that the quotient is the error criterion
F =F =
Betrag des Spitzenwertes
EfTektivwert Amount of the peak value
Effective value
des Signals bzw. des Signalbetrags am Signalfilterausgang verwendet wird oder eine Funktion dieses Quotienten.of the signal or the signal amount at the signal filter output or a function of this Quotient.
Erzielbare VorteileAchievable benefits
Die mit der Erfindung erzielbaren Vorteile bestehen darin, daß unter Beibehaltung aller bisher erkannten Vorzüge des oben genannten zweiten Prinzips die Realisierung vereinfacht und verbilligt wird. Das Problem der vom Signalpegel abhängig zu wählenden Schwellenhöhe beim oben genannten zweiten Prinzip, siehe [3] Seite 153, welcher auch von den variablen Filterparametern beeinflußt wird, entfällt beim erfin- to dungsgemäfen Kriterium. An Stelle des Wahrscheinlichkeitsmessers kann nun ein Effektivwertmesser (Thermoelement, Diodengleichrichter u. a.) verwendet werden.The advantages that can be achieved with the invention are that while retaining all previously recognized Advantages of the above-mentioned second principle, the implementation is simplified and cheaper. That Problem of the threshold height to be selected depending on the signal level in the above-mentioned second principle, see [3] page 153, which is also influenced by the variable filter parameters, does not apply to the erfinto appropriate criterion. Instead of the probability meter An effective value meter (thermocouple, diode rectifier, etc.) can now be used will.
Beschreibung und WirkungsweiseDescription and mode of operation
Die Wirkungsweise des erfindungsgemäßen Fehlerkriteriums wird anhand von F i g. 1 und F i g. 2 verdeutlicht F i g. 1 gibt in abgeänderter Darstellung das Bild 19 der Iiteratursxelle [3] wieder. Pkennzeichnet die Unterschreitungswahrscheinlichkeit, s den Signalwert, A dessen Spitzenwert und ±kA die Schwellenlagen. Das oben genannte zweite Prinzip basiert auf der Minimierung von F0. Das erfindungsgemäße Fehlerkriterium F besteht aus der positiven Wurzel aus dem Quotienten von Gesamtrechteckfläche mit dem Inhalt A2 dividiert durch den schraffierten Flächenanteil innerhalb der rechteckigen Gesamtfläche. Der schraffierte Flächenanteil entspricht nämlich dem Quadrat des Effektivwerts des Signals £ Die Minimierung von F bedeutet zugleich eine Minimierung von Fo, gleichgültig, wohin die Schwellen ±kA gelegt werden, solange ||The mode of operation of the error criterion according to the invention is illustrated in FIG. 1 and F i g. 2 illustrates FIG. Fig. 1 reproduces a modified representation of Fig. 19 of the literature reference [3]. P denotes the probability of falling below the signal , s the signal value, A its peak value and ± kA the threshold positions. The second principle mentioned above is based on the minimization of F 0 . The error criterion F according to the invention consists of the positive root of the quotient of the total rectangular area with the content A 2 divided by the hatched area portion within the rectangular total area. The hatched area portion corresponds namely to the square of the effective value of the signal £. The minimization of F also means a minimization of Fo, regardless of where the thresholds ± kA are placed, as long as ||
is Datensignale in RZ-Form oder pseudoternäre Basisbanddatensignale lassen sich dadurch entzerren, daß der Quotient F des Betrags des Signalfilterausgangssignals minimiert wird. Der Betrag eines Signals läßt sich in einfacher Weise durch Doppelweggleichrichtung bilden. Is data signals in RZ form or pseudoternary baseband data signals can be equalized by minimizing the quotient F of the amount of the signal filter output signal. The magnitude of a signal can be formed in a simple manner by full-wave rectification.
Hierzu 1 Blatt Zeichnungen1 sheet of drawings
Claims (1)
Effektivwert__ amount of the peak value
Rms value
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19792948549 DE2948549C2 (en) | 1979-12-03 | 1979-12-03 | Method for adaptive equalization of digital baseband signals |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19792948549 DE2948549C2 (en) | 1979-12-03 | 1979-12-03 | Method for adaptive equalization of digital baseband signals |
Publications (2)
Publication Number | Publication Date |
---|---|
DE2948549A1 DE2948549A1 (en) | 1981-06-04 |
DE2948549C2 true DE2948549C2 (en) | 1982-10-14 |
Family
ID=6087457
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
DE19792948549 Expired DE2948549C2 (en) | 1979-12-03 | 1979-12-03 | Method for adaptive equalization of digital baseband signals |
Country Status (1)
Country | Link |
---|---|
DE (1) | DE2948549C2 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3231768A1 (en) * | 1982-08-26 | 1984-03-01 | Standard Elektrik Lorenz Ag, 7000 Stuttgart | Equaliser with adaptive quantised feedback |
-
1979
- 1979-12-03 DE DE19792948549 patent/DE2948549C2/en not_active Expired
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3231768A1 (en) * | 1982-08-26 | 1984-03-01 | Standard Elektrik Lorenz Ag, 7000 Stuttgart | Equaliser with adaptive quantised feedback |
Also Published As
Publication number | Publication date |
---|---|
DE2948549A1 (en) | 1981-06-04 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
OP8 | Request for examination as to paragraph 44 patent law | ||
D2 | Grant after examination | ||
8330 | Complete disclaimer |