| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a system level automatic gain control ("System AGC") for automatically initializing and controlling analog microphone gain, in an environment where a plurality of inputs are received simultaneously. <P>SOLUTION: The System AGC also prevents applications from acting to separately control the gain, by intercepting external gain control commands and responding to the corresponding application, with a corresponding digital gain applied to the input signal from the microphone. Consequently, the System AGC avoids problems related to oscillations and instability in the microphone gain resulting from a plurality of applications trying to simultaneously control the gain, while preventing each application from adversely affecting audio capture signal of other application. Furthermore, the System AGC also acts to maximize the signal-to-noise (SNR) ratio of the microphone, without causing clipping according to the background environment. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
