A 6 KBPS Regular Pulse CELP Coder for Mobile Radio Communications

Delprat, M.; Lever, M.; Gruet, C.

doi:10.1007/978-1-4615-3266-8_18

Cited by 3 publications

(5 citation statements)

References 11 publications

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“…Previous works have shown that a time-invariant weighted synthesis filter (leading to fixed coefficients in R) could be used with a very small impact on subjective quality [5,8]. Here this solution was rejected, since the determination of R represents a small amount of computations.…”

Section: Basic Speech Codermentioning

confidence: 93%

“…The fmt pulse (initial phase p) is at one of the locations 0 to D-1. RP excitation has already shown its efficiency at higher rates [ 181 and here, in addition, the codebook is intrinsically robust to transmission errors [5,9].…”

Section: Excitation Modelmentioning

confidence: 98%

“…With an autocorrelation approach in the error minimization criterion (71, the matrix R = HL.H is a symetrical Toeplitz matrix whose ith diagonal term is the autocorrelation coefficient Ri-l of the impulse response of l/A(z/y). Then the signal y, = R.r, can be efficiently computed as the result of a particular filtering operation [5,8]. This greatly simplifies the computation of the numerator of P d i ) since no filtering of the excitation sequences is required anymore.…”

Section: Basic Speech Codermentioning

confidence: 99%

“…More recent works have shown that structured codebooks may greatly reduce complexity while maintaining high quality speech [5,9]. A binary Regular Pulse (RP) codebook, first introduced in [4], is particularly efficient to reduce both computational load and storing requirements.…”

Section: Excitation Modelmentioning

confidence: 99%

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Experiments with a regular pulse CELP coder for the pan European half rate channel

Gruet¹,

Pommaret²,

Delprat³

1991

[Proceedings] ICASSP 91: 1991 International Conference on Acoustics, Speech, and Signal Processing

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The paper descnbes the various experiments that have been carried out at Matra Communication for the realization of a combined speech and channel coder, to be submitted as a candidate for the standardization of the pan European half rate channel. The speech coder is based on the CELP technique and involves binary Regular Pulse excitation (RPCELP). Fast codebook search procedures are described and a new fast algorithm for closed-loop long term prediction is introduced. Then fractional pitch analysis can be performed with a small computational load.The channel coder uses a convolutional code with an error detection code for the most sensitive bits. The global solution was designed to reduce the effects of transmission errors. The proposed half rate codec is real time implemented in fixed point with a very low complexity. First results indicate that speech quality remains close to that of the full rate codec for all transmission conditions.

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Section: Basic Speech Codermentioning

confidence: 93%

Section: Excitation Modelmentioning

confidence: 98%

Section: Basic Speech Codermentioning

confidence: 99%

Section: Excitation Modelmentioning

confidence: 99%

See 2 more Smart Citations

Experiments with a regular pulse CELP coder for the pan European half rate channel

Gruet¹,

Pommaret²,

Delprat³

1991

[Proceedings] ICASSP 91: 1991 International Conference on Acoustics, Speech, and Signal Processing

Self Cite

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show abstract

“…The speech codec is a regular pulse code-excited linear prediction (RP-CELP) system [30] based on the CELP technique, which uses the properties of speech as an audio signal. The codec operates at a net bit rate of 4.6 kb/s.…”

Section: H Audio Codingmentioning

confidence: 99%

Mobile audio-visual terminal: system design and subjective testing in DECT and UMTS networks

Gill¹,

Cosmas

Pearmain

2000

IEEE Trans. Veh. Technol.

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It is anticipated that there will shortly be a requirement for multimedia terminals that operate via mobile communications systems. This paper presents a functional specification for such a terminal operating at 32 kb/s in a digital European cordless telecommunications (DECT) and universal mobile telecommunications system (UMTS) radio network. A terminal has been built, based on a PC with digital signal processor (DSP) boards for audio and video coding and decoding. Speech coding is by a phonetically driven code-excited linear prediction (CELP) speech coder and video coding by a block-oriented hybrid discrete cosine transform (DCT) coder. Separate channel coding is provided for the audio and video data. The paper describes the techniques used for audio and video coding, channel coding, and synchronization. Methods of subjective testing in a DECT network and in a UMTS network are also described. These consisted of subjective tests of first impressions of the mobile audio-visual terminal (MAVT) quality, interactive tests, and the completion of an exit questionnaire. The test results showed that the quality of the audio was sufficiently good for comprehension and the video was sufficiently good for following and repeating simple mechanical tasks. However, the quality of the MAVT was not good enough for general use where high-quality audio and video was needed, especially when transmission was in a noisy radio environment.

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Fractional excitation and other efficient transformed codebooks for CELP coding of speech

Delprat¹,

Gruet²,

Dervaux³

et al. 1992

[Proceedings] ICASSP-92: 1992 IEEE International Conference on Acoustics, Speech, and Signal Processing

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A 6 KBPS Regular Pulse CELP Coder for Mobile Radio Communications

Cited by 3 publications

References 11 publications

Experiments with a regular pulse CELP coder for the pan European half rate channel

Experiments with a regular pulse CELP coder for the pan European half rate channel

Mobile audio-visual terminal: system design and subjective testing in DECT and UMTS networks

Fractional excitation and other efficient transformed codebooks for CELP coding of speech

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