A comparative study of LPC parameter representations and quantisation schemes for wideband speech coding

No Thumbnail Available
File version
Author(s)
So, Stephen
Paliwal, Kuldip K
Griffith University Author(s)
Primary Supervisor
Other Supervisors
Editor(s)

M. Rangaswamy, F.J. Harris

Date
2007
Size
File type(s)
Location
License
Abstract

In this paper, we provide a review of LPC parameter quantisation for wideband speech coding as well as evaluate our contributions, namely the switched split vector quantiser (SSVQ) and multi-frame GMM-based block quantiser. We also compare the performance of various quantisation schemes on the two popular LPC parameter representations: line spectral frequencies (LSFs) and immittance spectral pairs (ISPs). Our experimental results indicate that ISPs are superior to LSFs by 1 bit/frame in independent quantiser schemes, such as scalar quantisers; while LSFs are the superior representation for joint vector quantiser schemes. We also derive informal lower bounds, 35 and 36 bits/frame, for the transparent coding of LSFs and ISPs, respectively, via the extrapolation of the operating distortion-rate curve of the unconstrained vector quantiser. Finally, we report and discuss the results of applying the SSVQ with dynamically-weighted distance measure and the multi-frame GMM-based block quantiser, which achieve transparent coding at 42 and 37 bits/frame, respectively, for LSFs. ISPs were found to be inferior to the LSFs by 1 bit/frame. In our comparative study, other quantisation schemes that were investigated include PDF-optimised scalar quantisers, the memoryless Gaussian mixture model-based block quantiser, the split vector quantiser, and the split-multistage vector quantiser with MA predictor from the AMR-WB (ITU-T G.722.2) speech coder.

Journal Title

Digital Signal Processing

Conference Title
Book Title
Edition
Volume

17

Issue
Thesis Type
Degree Program
School
Patent number
Funder(s)
Grant identifier(s)
Rights Statement
Rights Statement
Item Access Status
Note
Access the data
Related item(s)
Subject

Mechanical engineering

Communications engineering

Engineering

Information and computing sciences

Persistent link to this record
Citation
Collections