Speech Coding for Packet Networks

Signal Compression Laboratory Research Project

 

Researcher: Hosam Khalil
Faculty: Prof. Kenneth Rose
Research Focus: The design of a multi-stage vector quantizer (MSVQ) based source-channel coding system is optimized for packet networks. Resilience to packet loss is further enhanced by a proposed interleaving approach that ensures that a single lost packet only eliminates a subset of the vector stages. The design is optimized while taking into account compression efficiency,packet loss rate, and the interleaving technique in use.The new source-channel-optimized MSVQ is tested on memoryless line spectral frequency (LSF) parameter quantization in speech coders. A source-channel-optimized MSVQ is shown to yield a gain of up to 2.0 dB in SNR, for coding the LSFs, over traditional MSVQ and to substantially enhance the robustness of packetized speech transmission. Although the formulation is given in the context of packet networks, the work is directly extendible to the broader category of erasure channels.
Presentation:

Multi-Stage Vector Quantizer Design for Packet Networks