Name
Abstract | ||
|---|---|---|
This paper introduces a novel signal modification method for wide-band code-excited linear prediction (CELP) speech codecs to improve pitch prediction at low bit rates. The method is enabled only in stable voiced speech frames, and preserves the original time scale at the end of each frame. This feature helps to avoid artifacts and simplifies an encoder implementation. The signal modification includes a classification algorithm as an integral part. The classification algorithm detects the frames most suitable for signal modification and low bit rate coding, and can be employed in a rate selection module of variable bit rate (VBR) codecs. In this paper, the signal modification method is applied in an experimental VBR wide-band speech codec derived from the 3GPP adaptive multirate wideband (AMR-WB) standard (ITU-T Recommendation G.722.2). The codec fulfills the system requirements of IS-95/CDMA2000 Rate Set II, operating at source coding bit rates 12.65, 6.2, and 1.0 kb/s. The signal modification is used in the 6.2 kb/s mode dedicated for voiced speech frames. Listening test results demonstrate the good performance of the proposed method. The signal modification method is used in the Nokia/VoiceAge codec that was declared in April 2003 as the winner of the selection phase in the 3GPP2 CDMA2000 wide-band speech codec standardization. |
Year | DOI | Venue |
|---|---|---|
2005 | 10.1109/TSA.2005.851975 | IEEE Transactions on Speech and Audio Processing |
Keywords | Field | DocType |
linear predictive coding,speech codecs,speech coding,variable rate codes,3GPP adaptive multirate wideband standard,pitch prediction,signal modification,speech codecs,variable bit rate codecs,voiced speech frames,wideband code excited linear prediction,Signal modification,variable bit rate (VBR) coding,wide-band speech coding | Code-excited linear prediction,Vector sum excited linear prediction,Speech coding,Computer science,Adaptive Multi-Rate audio codec,Speech recognition,Full Rate,Harmonic Vector Excitation Coding,Codec2,Linear predictive coding | Journal |
Volume | Issue | ISSN |
13 | 5 | 1063-6676 |
Citations | PageRank | References |
2 | 0.60 | 7 |
Authors | ||
3 | ||
Name | Order | Citations | PageRank |
|---|---|---|---|
| Mikko Tammi | 1 | 13 | 2.83 |
| Milan Jelinek | 2 | 33 | 8.49 |
| Vesa T. Ruoppila | 3 | 11 | 3.03 |