Robust Speech Coding for the Indoor Wireless Channel

Gould, Kevin W.; Cox, R.V.; Jayant, N.; Melchner, Melvin J.

doi:10.1002/j.1538-7305.1993.tb00551.x

Cited by 6 publications

(1 citation statement)

References 3 publications

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“…The benefits of rate adaptation have led to the development of several variable rate speech and audio coding schemes [5]- [17]. In particular, subband coding is proposed as a flexible scheme for robust speech coding [13]- [15], and highquality audio compression [17]. A speech production model is not used, ensuring robustness to speech in the presence of background noise, and to nonspeech sources.…”

Section: Introductionmentioning

confidence: 99%

A perceptually based embedded subband speech coder

Tang

Shen

Alwan

et al. 1997

IEEE Trans. Speech Audio Process.

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A new scheme for robust, high-quality, embedded speech coding based on subband decomposition and perceptually optimized bit allocation and prioritization is presented. An infinte impulse response (IIR) quadrature mirror filterbank (QMF) performs subband decomposition. A perceptual model, computed using subband spectral analysis, optimizes the coder's perceptual quality. Dynamic bit allocation and prioritization is combined with embedded quantization resulting in little performance degradation relative to a nonembedded implementation. The coder output is scalable from high quality at higher bit rates to lower quality at lower bit rates, supporting a wide range of service and resource utilization. The lower bit-rate representation is obtained simply through truncation of the higher bit-rate representation. Since source-rate adaptation is performed through truncation of the encoded stream, interaction with the coder is not required, making the embedded coder ideally suited for rateadaptive communication systems. Performance for both speech and music was verified through subjective listening tests.

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Section: Introductionmentioning

confidence: 99%

A perceptually based embedded subband speech coder

Tang

Shen

Alwan

et al. 1997

IEEE Trans. Speech Audio Process.

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Speech Coding: Fundamentals and Applications

Hasegawa‐Johnson

Alwan

2003

Wiley Encyclopedia of Telecommunications

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In this chapter, we present an overview of the most widely used algorithms, standards, and applications of wideband and narrowband speech coding. Algorithms for speech coding are classified into four broad headings: (1) waveform coding techniques (including PCM, companded PCM, and DPCM), which are typically used for landline telephony, internet telephony, and secure military communications; (2) subband coding, including perceptually transparent multi‐rate and embedded coding which is mainly used for internet and digital audio applications; (3) linear predictive analysis by synthesis coding (LPC‐AS) algorithms, including multipulse LPC, CELP, SELP, VSELP, and low‐delay CELP, which are typically used for digital cellular and telephony; and (4) LPC vocoders, including advanced vocoder algorithms (e.g., MELP, MBE, and PWI) are used for applications such as secure telephony and satellite telephony. Applications in areas such as voiceover IP (VoIP) and digital cellular are emerging and require a speech coder to gracefully adapt to rapidly changing channel conditions—a need that is met by embedded and multirate speech coders associated with joint source‐channel coding algorithms. Measures of speech coder perceptual quality include subjective measures of intelligibility (DRT and DALT) and naturalness (MOS and DAM), as well as objective measures such as segmental SNR, Bark spectral distortion, PSQM, and PESQ. Speech coding standards are set by organizations including the ITU (for landline telephony), MPEG (for multimedia applications), ETSI (for European digital cellular), TIA (for U.S. digital cellular), and DDVPC (for United States military applications).

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Wireless Systems and Technologies: An Overview

Chang

Miska

Shober

1993

At&T Technical Journal

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The wondrous inventions of Marconi brought about the first wireless revolution, which dramatically transformed the ways people worked and played. The telecommunications industry is now in the midst of a second wireless revolution, which is projected to have an impact as large as that of the original. The current revolution began with the invention of cellular communications technology. As new discoveries were made and cellular technology advanced, another generation of wireless applications has emerged during the past decade. Recent developments, including AT&T's proposed $12.6 billion merger with McCaw Cellular Communications Inc., whose network now spans nearly one‐third of the United States, provide overwhelming proof of the tremendous potential of these technologies. Future applications will make it easier than ever for people to avail themselves of anywhere, anytime voice, data, and messaging services through the telecommunications network. This paper discusses the development of current cellular applications and technologies, and also explores the expanding wireless telecommunications network of the future.

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Robust Speech Coding for the Indoor Wireless Channel

Cited by 6 publications

References 3 publications

A perceptually based embedded subband speech coder

A perceptually based embedded subband speech coder

Speech Coding: Fundamentals and Applications

Wireless Systems and Technologies: An Overview

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