Zero-Delay Multiple Descriptions of Stationary Scalar Gauss-Markov Sources Using Feedback
Translated title
Zero-Delay Multiple Descriptions af stationære skalarer Gauss-Markov kilder med anvendelse af feedback
Author
Fuglsig, Andreas Jonas
Term
4. semester
Education
Publication year
2019
Submitted on
2019-06-07
Abstract
This thesis studies how to combine zero-delay source coding and multiple descriptions (MD) to enable robust real-time communication over unreliable networks. The focus is two-description ZDMD coding of stationary scalar Gauss–Markov sources under a mean-squared error criterion, with perfect decoder feedback. The main contributions are: (1) a new information-theoretic lower bound on the sum rate for ZDMD coding with feedback and mutually independent decoder side information, expressed as the sum of the directed information rate from the source to the MD reconstructions and the mutual information rate between the reconstructions; (2) a corresponding lower bound on the operational symmetric ZDMD rate–distortion function; (3) under technical assumptions, Gaussian test channels minimize this bound for stationary scalar Gauss–Markov sources; (4) the optimal Gaussian test channel is realizable via a double-branch architecture with two predictive coding loops, establishing achievability in a Gaussian coding scheme; and (5) numerical simulations using a simple, existing MD quantization method that mirrors the test-channel realization show high-rate performance within about 5 dB of the theoretical limits. Overall, the thesis provides both fundamental limits and a practical realization that support zero-delay, two-description robust source coding.
Denne afhandling undersøger, hvordan man kan kombinere zero-delay (øjeblikkelig) kildekodning og multiple descriptions (MD) for robust realtidskommunikation over upålidelige netværk. Fokus er på to-beskrivelses ZDMD-kodning af stationære skalar Gauss-Markov-kilder under et MSE-kriterium, i scenarier med perfekt dekoder-feedback. Arbejdet bidrager med: (1) en ny informationsteoretisk nedre grænse på sumraten for ZDMD-kodning med feedback og indbyrdes uafhængig sideinformation ved dekoderen, udtrykt som summen af den retningsbestemte informationsrate fra kilden til MD-rekonstruktionerne og den indbyrdes informationsrate mellem rekonstruktionerne; (2) en tilsvarende nedre grænse for den operationelle symmetriske ZDMD rate–distortionsfunktion; (3) under tekniske antagelser vises, at Gaussiske test-kanaler minimerer denne grænse for stationære skalar Gauss-Markov-kilder; (4) den optimale Gaussiske test-kanal kan realiseres via en dobbelt-grens struktur med to prædiktive kodningssløjfer, hvilket etablerer opnåelighed i et Gaussisk kodningsskema; og (5) numeriske simuleringer med en simpel, eksisterende MD-kvantiseringsmetode, der ligner test-kanal realiseringen, viser højrate performance inden for ca. 5 dB af de teoretiske grænser. Samlet set giver afhandlingen både teoretiske grænser og en praktisk realisering, der understøtter zero-delay robust kildekodning med to beskrivelser.
[This apstract has been generated with the help of AI directly from the project full text]