Speech Coding Algorithms: Foundation and Evolution of Standardized Coders
* Speech coding is a highly mature branch of signal processing deployed in products such as cellular phones, communication devices, and more recently, voice over internet protocol* This book collects many of the techniques used in speech coding and presents them in an accessible fashion* Emphasizes the foundation and evolution of standardized speech coders, covering standards from 1984 to the present* The theory behind the applications is thoroughly analyzed and proved
Why Read This Book
You will get a focused, engineering-oriented tour of how modern speech coders work — from the source/filter speech model and linear prediction to CELP-family encoders — with clear links to real standards (G.7xx, GSM, AMR). The book balances algorithmic theory, practical design choices, and the historical evolution of standardized coders so you can both understand and implement codec building blocks.
Who Will Benefit
DSP engineers, communications engineers, and graduate students working on speech/voice codecs, VoIP/mobile voice systems, or anyone implementing and evaluating standardized speech coders.
Level: Advanced — Prerequisites: Undergraduate DSP and signals & systems, basic probability and linear algebra, and familiarity with digital filter concepts and sampling theory; MATLAB or C experience helpful for implementing examples.
Key Takeaways
- Implement and analyze linear predictive coding (LPC) analysis/synthesis and residual quantization
- Explain and implement waveform, parametric (vocoders), and hybrid speech coding architectures
- Design and understand CELP and ACELP encoder/decoder building blocks including codebook search, long-term prediction, and perceptual weighting
- Evaluate codec performance using objective measures and understand perceptual trade-offs and bit-rate vs. quality design choices
- Understand the structure, rationale, and differences of major standards (G.711, G.726, G.728/G.729 families, GSM, early AMR) and how they evolved
- Apply quantization, entropy coding, and rate control techniques used in low-bit-rate speech coders
Topics Covered
- 1. Introduction: Speech, Applications, and Standards
- 2. Speech Production Model and Perceptual Considerations
- 3. Linear Prediction and LPC Coding
- 4. Quantization and Entropy Coding for Speech
- 5. Waveform and Hybrid Coders (PCM, ADPCM)
- 6. Vocoders and Formant Coding
- 7. Code-Excited Linear Prediction (CELP) — Fundamentals
- 8. Analysis-by-Synthesis, Perceptual Weighting, and Codebook Design
- 9. Algebraic CELP and Low-Bit-Rate Techniques
- 10. Descriptions of Standardized Coders (ITU-T and GSM families)
- 11. Error Resilience, Packet Loss, and Network Considerations
- 12. Objective and Subjective Quality Assessment
- 13. Evolution of Standards and Future Directions
Languages, Platforms & Tools
How It Compares
Covers similar ground to Gold & Morgan's Speech and Audio Signal Processing but is more narrowly focused on codec algorithms and standardized implementations rather than broad signal processing theory.
