Patent · US Expired

Method and apparatus for adaptive rate communication system

US5940439A · kind A · utility

117Cited by
24References
4Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 26, 1997
Grant dateAug 17, 1999
Priority date
Expiry dateFeb 26, 2017

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04L1/0038
  • WIPO fieldDigital communication
  • WIPO sectorElectrical engineering

Abstract

A system is disclosed for an adaptive rate voice system to provide improvements in coded operation over changing communication channel (50) conditions. This adaptive rate system efficiently determines optimal voice/channel coding rates , coding strategies and modulation/demodulation for optimum voice quality and intelligibility. A system state estimator (100), channel status estimator (110) and channel status monitor (120) provides feedback in the system to optimize the communication channel. The system maintains a continuous link despite changing channel conditions and minimizes delays through the system. Even though simple in design, it provides relatively low complexity and powerful channel coding operation. Operating conditions are thus extended for CDMA and portable communication systems. Voice intelligibility is preserved in extremely noisy or even hostile channel conditions.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.