| 摘要 |
A system comprises an enhanced downsampling operation for digital data. In the preferred embodiment, a downsampling filter has a quantity of filter coefficients equal to 4(a)+1, where (a) is an integer. In this case the even-numbered coefficients are, to the degree of accuracy required, equal to zero. Also the central even-numbered coefficient is equal to ½. As multiplication by ½ in a binary digital system may be executed by a simple right shift, the total number of coefficient-sample multiplications may be reduced to 2(a). The filter design wherein the even-numbered coefficients equal zero also has the additional benefit of reducing the number of storage locations for the filter coefficients. A further aspect of the present invention is the segregation of the input data stream into even and odd-numbered sample buffers.
|
