Real-time vector excitation coding of speech at 4800 bps
- 24 March 2005
- conference paper
- Published by Institute of Electrical and Electronics Engineers (IEEE)
- Vol. 12, 2189-2192
- https://doi.org/10.1109/icassp.1987.1169424
Abstract
In Vector Excitation Coding (VXC), speech is represented by applying a sequence of excitation vectors to a time-varying speech production filter with each vector chosen from a codebook using a perceptually-based performance measure. Although VXC is a powerful technique for achieving natural and high quality speech compression at low bit-rates, it suffers as other excitation coders do from a very high computational complexity. Recent research has shown that codebook search computation can be reduced to approximately 40 MFlops without compromising speech quality. However, this operation count still prohibits a practical real-time implementation of the coder using today's DSP chips. We present a real-time 4.8 kb/s Pulse Excitation VXC coder (PVXC) which achieves high reconstructed speech quality and incorporates new techniques which reduce the codebook search complexity to only 0.55 MFlops. The coder utilizes an optimized excitation codebook and a promising new interframe vector predictive LPC parameter quantization scheme. A preliminary implementation using a single floating-point signal processor is described.Keywords
This publication has 7 references indexed in Scilit:
- CELP Coding for high-quality speech at 8 kbit/sPublished by Institute of Electrical and Electronics Engineers (IEEE) ,2005
- Complexity reduction methods for vector excitation codingPublished by Institute of Electrical and Electronics Engineers (IEEE) ,2005
- Efficient procedures for finding the optimum innovation in stochastic codersPublished by Institute of Electrical and Electronics Engineers (IEEE) ,2005
- Code-excited linear prediction(CELP): High-quality speech at very low bit ratesPublished by Institute of Electrical and Electronics Engineers (IEEE) ,2005
- Vector Predictive Coding of Speech at 16 kbits/sIEEE Transactions on Communications, 1985
- Predictive Coding of Speech at Low Bit RatesIEEE Transactions on Communications, 1982
- An Algorithm for Vector Quantizer DesignIEEE Transactions on Communications, 1980