RU99106430A - MICROPHONE MUFFLING IN RADIO COMMUNICATIONS SYSTEMS - Google Patents

Claims (19)

1. A remote station comprising a voice input device for receiving voice signals; an encoding circuit for encoding said voice signals to generate encoded speech signals; a generator for generating alternative information signals; a transmitter for selectively transmitting either said encoded speech signals or said alternative information signals; and a muting input switched between muting mode and non-muting mode, wherein said transmitter selectively transmits said alternative information signals when said muting input is set in said muting mode, and transmits said encoded speech signals when said muting input is set in said non-muting mode muting.  2. The remote station of claim 1, wherein said coding chain is a linear prediction encoder driven by a code.  3. The remote station of claim 1, wherein said coding chain uses long-term pulse excitation prediction to generate said coded speech signals.  4. The remote station of claim 1, wherein said voice input device is a microphone.  5. The remote station of claim 1, wherein said generator generates, as said alternative information signals, comfort noise information.  6. The remote station of claim 1, wherein said generator generates, as said alternative information signals, silence frames.  7. The remote station of claim 1, further comprising a voice activity detector that monitors the activity level of said received voice signals.  8. A mobile station comprising means for receiving voice signals; means for encoding said voice signals into coded speech frames; means for generating background frames; muting mode selector; and means for transmitting said background frames when selecting said muting mode and, otherwise, transmitting said frames of encoded speech.  9. The mobile station of claim 8, wherein said means for receiving voice signals includes a microphone.  10. The mobile station of claim 8, wherein said encoding means includes an encoder with linear prediction driven by a code.  11. The mobile station of claim 8, wherein said coding chain uses long-term pulse excitation prediction to generate said coded speech signals.  12. The mobile station of claim 8, wherein said background frame generating means generates silence frames.  13. The mobile station of claim 8, wherein said background frame generating means generates comfort noise frames.  14. The mobile station of claim 8, wherein said selection means includes a button on said mobile station.  15. The mobile station of claim 8, further comprising means for detecting a level of voice activity associated with said received voice signals.  16. A method for transmitting background noise during selective muting of a radio communication device, comprising the steps of receiving input voice signals; encoding said input voice signals to generate frames of encoded voice; determining whether the muting function has been activated; transmitting said coded speech frames if said muting function has not been activated; and transmitting information frames other than said encoded speech frames if said muting function has been activated.  17. The method according to p. 16, in which said step of determining is independent of the level of voice activity in close proximity to said radio communication device.  18. The method of claim 16, wherein said radio communication device is a mobile station.  19. The method of claim 16, wherein said information frames other than said coded speech frames include either silence frames or comfort noise frames.