| 摘要 |
<p>A system and method of masking an objectionable artifact in a mobile telephone. The process starts by referring to the design characteristics of the mobile phone to determine the expected level and source of objectionable artifacts that will be apparent during operation of the mobile phone. The noise necessary to mask the objectionable artifact is then calculated. The masking noise signal is then created within the mobile telephone and superimposed over the objectionable artifact. The masking noise signal is typically created in a digital signal processor (DSP) resident within the mobile telephone using a pseudo-noise generator. The masking noise signal can be stored as a look-up table in the digital signal processor (DSP) of the mobile telephone. To further enhance the effectiveness of the masking process, the masking noise signal is filtered to best match the objectionable artifact. The masking noise signal can be low pass filtered for objectionable artifacts that are lower in frequency. The masking noise signal can be high pass filtered for objectionable artifacts that are higher in frequency. Or, the masking noise signal can be band pass filtered for objectionable artifacts regardless of frequency. In an alternative embodiment, the masking noise signal can be created as a band-limited masking noise signal created within a pre-determined frequency bandwidth correlated to the frequency bandwidth of the objectionable artifact.</p> |
