Advances in Speech Coding

Speech coding has been an ongoing area of research for several decades, yet the level of activity and interest in this area has expanded dramatically in the last several years. Important advances in algorithmic techniques for speech coding have recently emerged and excellent progress has been achieved in producing high quality speech at bit rates as low as 4.8 kb/s. Although the complexity of the newer more sophisticated algorithms greatly exceeds that of older methods (such as ADPCM), today's powerful programmable signal processor chips allow rapid technology transfer from research to product development and permit many new cost-effective applications of speech coding. In particular, low bit rate voice technology is converging with the needs of the rapidly evolving digital telecom­ munication networks. The IEEE Workshop on Speech Coding for Telecommunications was held in Vancouver, British Columbia, Canada, from September 5 to 8, 1989. The objective of the workshop was to provide a forum for discussion of recent developments and future directions in speech coding. The workshop attracted over 130 researchers from several countries and its technical program included 51 papers. Front Matter....Pages i-ix Introduction....Pages 1-2 Front Matter....Pages 3-3 Backward Adaptive Prediction Algorithms in Multi-Tree Speech Coders....Pages 5-12 Backward Adaptive Configurations for Low-Delay Vector Excitation Coding....Pages 13-23 A Robust Low-Delay CELP Speech Coder at 16 Kb/s....Pages 25-35 An Efficient Variable-Bit-Rate Low-Delay CELP (VBR-LD-CELP) Coder....Pages 37-46 A Trellis-Searched 16 Kbit/Sec Speech Coder with Low-Delay....Pages 47-56 Hybrid Backward Adaptive Pitch Prediction for Low-Delay Vector Excitation Coding....Pages 57-66 Front Matter....Pages 67-67 Vector Sum Excited Linear Prediction (VSELP)....Pages 69-79 An Error Protected Transform Coder for Cellular Mobile Radio....Pages 81-86 A Multipulse Speech Codec for Digital Cellular Mobile Use....Pages 87-96 Transmitting Digital Speech in a Portable Radio Environment....Pages 97-107 A Study on Speech and Channel Coding for Digital Cellular....Pages 109-118 Front Matter....Pages 119-119 The Dod 4.8 Kbps Standard (Proposed Federal Standard 1016)....Pages 121-133 Analysis-by-Synthesis Linear Predictive Speech Coding at 4.8 kbit/s and Below....Pages 135-143 Binary Pulse Excitation: A Novel Approach to Low Complexity CELP Coding....Pages 145-156 Speech Coding with Dynamic Bit Allocation (Multimode Coding)....Pages 157-166 7 KBPS — 7 MIPS — High Quality ACELP for Cellular Radio....Pages 167-177 A 6 KBPS Regular Pulse CELP Coder for Mobile Radio Communications....Pages 179-188 Front Matter....Pages 189-189 Beyond Multipulse and CELP Towards High Quality Speech at 4 Kb/s....Pages 191-201 Sine-Wave Amplitude Coding at Low Data Rates....Pages 203-213 Front Matter....Pages 189-189 The Multi-Band Excitation Speech Coder....Pages 215-223 Phonetic Segmentation for Low Rate Speech Coding....Pages 225-234 Vector Excitation Homomorphic Vocoder....Pages 235-244 A 400-bps Speech Coding Algorithm for Real-Time Implementation....Pages 245-254 Front Matter....Pages 255-255 Source-Dependent Channel Coding and its Application to CELP....Pages 257-266 Vector Trellis Quantization for Noisy Channels....Pages 267-276 Application of Stochastic Coding Schemes in Satellite Communication....Pages 277-286 A Real Time Implementation of a 4800 bps Self Excited Vocoder....Pages 287-297 A Real-Time Full Duplex 16/8 kbps CVSELP Coder with Integral Echo Canceller Implemented on a Single DSP56001....Pages 299-308 Front Matter....Pages 309-309 Improved Excitation Sequence Quantization in Regular Pulse Excitation Speech Coding....Pages 311-320 On Improving the Performance of Pitch Predictors in Speech Coding Systems....Pages 321-327 Efficient Encoding of the Long-Term Predictor in Vector Excitation Coders....Pages 329-338 Constrained-Stochastic Excitation Coding of Speech at 4.8 kb/s....Pages 339-348 Speech Coding Using Least-Squares Estimation....Pages 349-358 Qualitative Analysis and Enhancement of Sine Transform Coding....Pages 359-366 An ADM Speech Coding with Time Domain Harmonic Scaling....Pages 367-373 Back Matter....Pages 375-378