Transmission of comfort noise parameters during discontinuous transmission

• US 6,816,832 B2
• Filed: 06/11/2001
• Issued: 11/09/2004
• Est. Priority Date: 11/14/1996
• Status: Expired due to Fees

• Current Assignee: Nokia Corporation
• Original Assignee: Nokia Corporation
• Inventors: Alanara, Seppo, Kapanen, Pekka
• Primary Examiner(s): Nguyen, Simon
• Application Number:
  US09/878,503
• Publication Number:
  US 20010046843A1
• Time in Patent Office: 1,247 Days
• Field of Search: 455/63.1, 455/79, 455/222, 455/228, 455/423, 455/570, 455/95, 455/116, 704/214, 704/215, 704/226, 704/233, 704/208, 704/205
• US Class Current: 704/205
• CPC Class Codes: G10L 19/012 Comfort noise or silence coding

Abstract

A comfort noise block, that include a hangover period and comfort noise parameters, is transmitted in such a manner that it is not interrupted by other messages, such as FACCH messages. This is accomplished in a mobile station by a determination of whether any FACCH messages are required to be transmitted. If such FACCH messages exist, a further determination may be made as to which transmission can be made in the shortest time (i.e., the FACCH message or messages or the comfort noise parameters message), and this transmission is made first. In any event the comfort noise parameters block is transmitted without interruption. In a further embodiment of this invention the comfort noise parameters message is transmitted by being concatenated with another message, such as a neighbor channel measurement results message, so as to reduce overhead, conserve bandwidth, and reduce power consumption. An element of the comfort noise parameters message is a Random Excitation Spectral Control (RESC) information element, which is used in the decoder for improving the spectral content of the generated comfort noise so as to better match the background noise at the transmitter.

Claims

1. A method for transmitting comfort noise (CN) parameters in a digital mobile station that operates in a discontinuous transmission (DTX) mode, comprising the steps of:

generating a comfort noise parameters message in response to a voice activity detector detecting an absence of speech; and

transmitting the comfort noise parameters message from the mobile station to a base station by concatenating the comfort noise parameters message with another message that is scheduled for transmission to the base station.

2. A method as in claim 1, wherein the another message scheduled for transmission is transmitted over a Fast Associated Control Channel (FACCH).

3. A method as in claim 1, wherein the another message scheduled for transmission to the base station is transmitted at one second intervals.

4. A method as set forth in claim 1, and including a step of generating a Random Excitation Spectral Control (RESC) information element as a part of the comfort noise parameters message that is concatenated with the another message, the RESC information element being used for improving a spectral content of generated comfort noise.

5. A mobile station operative with a base station, said mobile station comprising:

a transmitter;

an input speech transducer;

a voice activity detection (VAD) function coupled to said speech transducer; and

a controller having an input coupled to an output of said VAD function, to an output of said speech transducer, and to an input of said transmitter, said controller being responsive to said VAD function indicating an absence of user speech for initiating a Discontinuous Transmission (DTX) mode of operation and for transmitting at least one comfort noise (CN) block, the comfort noise block being comprised of a hangover period following a detected absence of speech and comfort noise parameters, said controller being operative for transmitting the comfort noise parameters message from the mobile station to the base station by concatenating the comfort noise parameters message with another message transmitted over a control channel to the base station.

6. A method for transmitting comfort noise (CN) parameters in a digital mobile station that operates in a discontinuous transmission (DTX) mode, comprising the steps of:

generating a comfort noise parameters message in response to a voice activity detector detecting an absence of speech; and

transmitting the comfort noise parameters message over a traffic channel by using Digital Control Channel (DCCH) channel coding and intraslot interleaving, thereby enabling the comfort noise parameters message to be transmitted in one time slot from the mobile station to a base station.

7. A method as set forth in claim 6, and including a step of generating a Random Excitation Spectral Control (RESC) information element as a part of the comfort noise parameters message, that is transmitted to the base station, the RESC information element being used for improving a spectral content of generated comfort noise.