Lecture "Adaptive Filters"

Basic Information

Lecturers:   Gerhard Schmidt (lecture) and Tobias Hübschen (exercise)
Room:   F-SR I
Language:   English
Target group:   Students in electrical engineering and computer engineering
Prerequisites:   Basics in system theory

Students attending this lecture should learn the basics of adaptive filters. To achieve this, necessary algorithms will be derived and applied to problems arising in speech and audio processing. The algorithms comprise Wiener filtering, linear prediction, and adaptive schemes such as the NLMS algorithm, affine projection, and the RLS algorithm. For applications from speech and audio processing we use noise and reverberation reduction, echo cancellation, and beamforming.

Topic overview:

  • Introduction and application examples
  • Signal properties and cost functions
  • Wiener filter and principle of orthogonality
  • Linear prediction
  • RLS algorithm
  • LMS algorithm and its normalized version
  • Affine projection algorithm
  • Control of adaptive filters
  • Efficient processing structures
  • Applications of linear prediction



no current news



The following schedule regarding lectures and excercises is preliminary and may be adapted during the semester.

Date   Content
xx.xx.2020   tbd


Lecture Slides

  Slides of the lecture "Introduction"
(Introduction, boundary conditions of the lecture, applications)
  Slides of the lecture "Wiener Filter"
(basics, principle of orthogonality, suppression of background noise)
  Slides of the lecture "Linear Prediction"
(derivation of linear prediction, Levinson-Durbin recursion)
  Slides of the lecture "Algorithms (Part 1 of 2)"
(RLS algorithm, LMS algorithm [part 1 of 2])
  Slides of the lecture "Algorithms (Part 2 of 2)"
(LMS algorithm [part 2 of 2], affine projection algorithm)
  Slides of the lecture "Control"
(basic aspect, pseudo-optimal control parameters)
  Slides of the lecture "Processing Structures"
(polyphase filterbanks, prototype lowpass filter design)
  Slides of the lecture "Applications of Linear Prediction"
(Improving the speed of convergence, filter design)



  Extension for the lecture "Wiener Filter"
(derivation of the error surface)


Matlab Demos

  Matlab demo (GUI based) for adaptive system identification
  Matlab demo (GUI based) for adaptive noise suppression
  Matlab demo (GUI based) for linear prediction
  Matlab demo (GUI based) for the NLMS algorithms
  Matlab demo (GUI based) for prediction-based filter design



The first exercise will be on 06.05.2019 at 8.15 h in F-SR I. Please prepare by reviewing the topics Wiener Filter and Linear Prediction.

The second exercise will be on 03.06.2019 at 8.15 h in F-SR I. Please prepare by reviewing the topics Algorithms and Control.

At the end of the semester, each student will give a talk about a certain topic as a prerequisite to sit the exam. The aim is both to give you the chance to work on an adaptive filter-related topic that interests you, and to improve your presentational skills. The talks should take ten minutes, plus 2.5 minutes of discussion and 2.5 minutes of feedback.

Please contact This email address is being protected from spambots. You need JavaScript enabled to view it. with your topic suggestion. Below you can find the current schedule of the talks.

Date   Room   Time   Topic   Presenter(s)
xx.xx.2020   tbd   xx:x h        




Below is the list of students with their exam dates. If you do not have a date for the exam yet please register in the online booking system. You can find the booking system here.

Date   Time   Students (matriculation numbers)   Assessor
xx.xx.2020   xx:xx h       Tobias Hübschen



  Current evaluation     Completed evaluations

Website News

20.10.2019: We had a very good retreat on the island of Sylt.

07.08.2019: Talk from Juan Rafael Orozco-Arroyave added.

11.07.2019: First free KiRAT version released - a game for Parkinson patients

25.06.2019: About 30 pupils from the Isarnwohld-Schule in Gettorf visited us.

02.05.2019: Christin Baasch finished sucessfully her defense on the evaluation of Parkinson speech.

30.11.2018: New student project on driver distraction added.

Recent Publications


J. Reermann, E. Elzenheimer and G. Schmidt: Real-time Biomagnetic Signal Processing for Uncooled Magnetometers in Cardiology, IEEE Sensors Journal, Volume 15, Number 10, Pages 4237-4249, June 2019, doi: 10.1109/JSEN.2019.2893236


Prof. Dr.-Ing. Gerhard Schmidt

E-Mail: gus@tf.uni-kiel.de

Christian-Albrechts-Universität zu Kiel
Faculty of Engineering
Institute for Electrical Engineering and Information Engineering
Digital Signal Processing and System Theory

Kaiserstr. 2
24143 Kiel, Germany

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DSS-Retreat 2019

As in the last year we spent a couple of days (15.10.2019 till 18.10.2019) on the island Sylt to reflect our past, current, and future research work. Due to a "cold wave" we were a bit reduced this year, but anyhow, we had a very good (and producive) time on this beautiful island. Beside our research plans (reflecting the last year and planning of the next years), we also discussed teaching ...

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