Assumed knowledge: It is essential that you are familiar with IIR and FIR filtering, the sampling theorem, the discrete Fourier transform, random signals, auto- and cross-correlation and frame-by-frame processing. Students who are not confident in their knowledge from previous signal processing courses (especially the topics mentioned) are strongly advised to revise their previous course materials as quickly as possible to avoid difficulties in this course.

Speech coding refers to digital compression and transmission of speech. This course provides an in-depth perspective to ACELP, the most commonly used speech coding algorithm. We will study the speech production models on which it is based, the perceptual models which are used for its optimization, and most importantly, go through the theory and practice of the most important concepts, linear prediction (LP), long time prediction (LTP), algebraic codebooks, line spectral frequencies (LSFs) and windowing. In addition, we will look at the big picture, the additional challenges that emerge when building a commercial speech coding product.

The goal of this course is to provide a strong foundation for researchers, engineers, and graduate students who are interested in the problem of speech coding.

Relation to other courses
This course is the most advanced course offered by the university on this topic, and serves as an excellent basis from which to commence research in the area. Various aspects of the course bring students up to date with the very latest developments in the field, as seen in recent international standards, conferences and journals. This course builds on Sprach- und Audiosignalverarbeitung (by Prof. Kellermann), and is well complimented by Mensch-Maschine-Schnittstelle (by Prof. Rabenstein), Praxis der Audiodatenkompression (Dr. Grill), Speech Enhancement (Prof. Habets) and Selected Topics in Perceptual Audio Coding (Prof. Herre), which deal with many other signal processing methods and gives an understanding of human auditory perception (also a key part of speech coding) and audio compression techniques.