A Multipulse Speech Codec for Digital Cellular Mobile Use
The capacity of the cellular system depends on spectrum utilization and the frequency reuse pattern. Conversion to digital transmission will initially increase the spectrum utilization by a factor of three. Digital speech compression allows three virtual channels to be transmitted over a single 30 KHz bandwidth radio channel using a TDMA (time-division multiple access) format. Improved voice coding techniques are expected to increase the capacity by an additional factor of two in the next few years.
The digital transmission technique will support many new customer services such as data and FAX transmission, encryption and anti-fraud features. Additional services may be based on the ability to determine vehicle locations by triangularization from the base stations.
KeywordsMean Opinion Score Virtual Channel Pulse Position Synthesis Filter Speech Codec
Unable to display preview. Download preview PDF.
- B. S. Atal and J. R. Remde, “A new model of LPC excitation for producing natural-sounding speech at low bit rate”, Proc. Int. Conf. on Acoustics, Speech and Signal Processing, Paris, France, 1982, pp. 614–617Google Scholar
- M. Berouti, H. Garten, P. Kabal, and P. Mermelstein, “Efficient computation and encoding of the multipulse excitation for LPC,” Proc. Int. Conf. on Acoustics, Speech and Signal Processing, San Diego, California, 1984, pp. 10.1.1–10.1.4.Google Scholar
- M. R. Schroeder and B. S. Atal, “Code-excited linear prediction (CELP): high quality speech at very low bit rates,” Proc. Int. Conf. on Acoustics, Speech and Signal Proc., March 1985, pp. 937–940.Google Scholar
- S. Lin and D. J. Costello, Error Control Coding: Fundamentals and Applications, Prentice-Hall Inc., 1983.Google Scholar
- O. J. Wasem, D. J. Goodman, C. A. Dvorak, and H. G. Page, “The effect of waveform substitution on the quality of PCM packet communications,” IEEE Trans, on Acoustics, Speech and Signal Proc., vol. 36, no. 3, March 1988.Google Scholar