| 摘要 |
<p>A method of improving voice quality in low-rate dynamic bit allocation sub-band coding (DBASC) by inserting synthetic filler signals for non-transmitted signal bands. Large spectral holes may exist in an output voice speech spectrum of DBASC with a low transmission rate. The holes are caused by low energy signal sub-bands that are not transmitted and create noticeable artifacts in the received voice signal. To avoid these artifacts, the spectral holes in the received signal are filled with synthetic signals generated from the received signal. The synthetic filler signals are signals from transmitted energy bands that are scaled to the energy level of the non-transmitted band.</p> |
