Lutz Leutelt
		Institute for Circuits & Systems Theory Faculty of Engineering of the Christian-Albrechts-University , Kiel Kaiserstraße 2 D-24143 Kiel Germany Phone: +49-431-880-6132 Fax : +49-431-880-6128 eMail: LL@tf.uni-kiel.de

Projects:

• MPEG-4 HVXC Speech Codec (Project in Cooperation with Industry)

Survey of Implementation and Complexity Aspects of Fixed-point Harmonic Vector Excitation Coder (HVXC)


• BMBF Project M4M: MPEG Fo(u)r Mobiles (Project in Cooperation with Industry)

Performance Optimization of MPEG-4 Code Excited Linear Prediction (CELP) Narrow/Wideband-Encoder for Mobile Systems

• Publications:
• project reports remain unpublished

Research:

• Speaker Characteristics, Voice Conversion and Speech Coding and Synthesis

• Publications:
• Leutelt, L. ; Heute, U. : Voice Conversion: Adaptation of relative local Speech Rate by MPEG-4 HVXC.EUSIPCO (2002). (Abstract)
• Leutelt, L. : An MPEG-4 HVXC Based Interspeaker Pitch Prediction for Voice Conversion. Proceedings ECMCS 2001, Budapest, 2001. (Abstract)

• Previous publications:
• Leutelt, L. : Development of circuits in CMOS technology for optical data receivers, 1998 (Master/Diploma thesis, in German)
• Jasinski, P. ; Leutelt, L. ; Zajt,T. ; Nowakowski, A. : Low-cost PC Controlled Potentiostat, 40th scientists meeting of SITP Chem and PTCh, Gdansk, 1997 (in Polish)
• Leutelt, L. : Development of a PC Controlled Potentiostat for AC Voltammetry , 1997 (Undergraduate thesis/Studienarbeit, in German)

Teaching

• Advanced Signals and System (Exercises, in English)

  1. Discrete Signals definitions, deterministic and stochastic signals. 1.1. Stochastic Signals probability; expectation, moments. 1.2. Examples deterministic signals, stochastic signals. 1.3. Simple Operations on Stochastic Signals summation, mapping. 2. Spectra idea of superposition representations; superposition of impulse and step sequences; spectra of deterministic and stochastic signals. 2.1. FOURIER, z-, and Discrete FOURIER Transformation definitions, existence, periodicity, background; characteristics, rules, theorems; examples; one-sided z-transformation, inverse z-transformation and convergence, rational z-transform functions. 3. Spectra of Stochastic Signals definitions, relation to continuous random-signal spectra, examples; processes and signals; stationarity and ergodicity, short-time PDS, periodogram. 4. Discrete Systems system descriptions and classification 4.1. Discrete Linear Systems and their Response to Deterministic Signals reactions on elementary signals; raction on general deterministic signals (impulse and step response, transfer function and frequency response). 4.2. Discrete Linear Systems and their Response to Stochastic Signals 5. Idealised Discrete LTI Systems background; ideal transmission system; attenuation distortions; phase distortions. 6. HILBERT Transformation One-Sided Spectra, Analytic Signal, instantaneous amplitude, phase, and frequency; one-sided signals, causality. 7. State-Space Description definitions, basic structure, signal-flow graphs; transfer, impulse-response, and transition matrices; stability; minimum-phase, allpass configurations. 7.1. From I/O to State-Space Description difference equation; direct and canonical realizations. 7.2. From SFG to State-Space Description 1-st, 2-nd, 4-th canonical forms. 8. Generalisations for Signals, Systems, and Spectral Transformations Generalised Discrete Fourier and Cosine Transformations (GDFT, GDCT, DCT); generalised basis sequences; short-time spectra; 2-D signals and their spectra; 2-D systems.

• Digital Signal Processing I (Exercises, in German)

  Signal digitisation (analogue-to-digital and digital-to-analogue conversion, quantisation characteristics, quantisation noise), sample and hold; sampling of functions and sequences with/without phase shift; down- and up-sampling (decimation, interpolation); DFT and FFT (convolution via DFT, fast DFT evaluation, radix-2/DIT FFT and alternatives, transformation of real sequences, "pruning" and "zoom" FFT), spectral analysis of infinite sequences (windowing, periodograms of random signals); digital filters (difference and state equations, equivalent realisations/transformed structures, diagonal form, transition matrix, observability, controllability), realisation effects (input, arithmetic, and coefficient errors), filter types, non-recursive filters (state-space description, linear-phase filters

• Technik AG (Lab, in German)

  Introduction for students of grammar schools (age 16-18yrs) to analog and digital processing of speech and music signals



• Basic Lab II (Electrical Engeneering Part, in German)

  Each part consists of 12 experiments in Electrical Engineering, Computer Engineering and Materials Science.

• Signals and Systems (Exercises, in German)

  This course teaches basics in systems theory for electrical engineering and information technologie. This basic course is restricted to continuous and deterministic signals and systems. Basic classes of signals and systems; elementary signals: step, impulse, harmonic exponential functions, linear timeinvariant (LTI) systems, linear superposition, Fourier series, Fourier transform, Laplace transform and their properties; convolution; response of LTI systems to elementary and arbitrary signals, rational transfer-functions, partial fraction expansion, system differential equation; pole-zero diagram, stability, low-pass, band-pass, minimum-phase systems, transient response; modulation, linear modulation and demodulation of amplitude (AM), nonlinear angular modulation (FM, PM), frequency-multiplex, pulse-amplitude-modulation, sampling, theorem, aliasing, pulse-code-modulation, quantization, time-multiplex; fundamentals of information theory.