| 摘要 |
A method and apparatus of providing an audio output to a user in a communications system in which the audio to be output to a user, preferably an audio frame, is assessed before it is broadcast to the user, and then selectively changed on the basis of the assessment. The assessment may be carried out in the audio encoding process, in the audio decoding process and/or after the audio decoding process. The selective changing of the audio output may comprise selectively replacing the audio output and/or re-encoding of the audio output. The invention aims to overcome the problem of howl/squeal in the TETRA decoder caused when an error arises in the codebook index values and extraction which is caused by the impulse response of the TETRA decoder filter going unstable. |
