| 摘要 |
<p>An improved VQ system uses a first class-1 table (42) and second class-2 table (44) for vector values having different degrees of signal correlation. For a selected signal segment, the VQ system determines a vector Xbar1 representing a difference between the signal values in the selected segment and an average of a selected group of signal values in a preceding segment, and for the same signal segment, determines another vector Xbar2 representing a difference between the signal values in the selected signal segment and an average of a selected group of signal values in the selected signal segment. The system finds a class-1 best match entry (76) in the class-1 table for the vector Xbar1, and finds a class-2 best match entry (78) in the class-2 table for the vector Xbar2. After determining the best match entries, the improved VQ systems selects (94) one of the class-1 or class-2 best match entry.</p> |
