Flexible decimator

#This invention relates to the field of digital signal processing, and more particularly to a decimator.

#Digital filtering is employed in many areas, for example, in measurement systems, source coding, echo cancellation etc. A relatively common filter function is decimation.

#A decimator is a structure that combines samples into a single sample. It typically consists of an electronic hardware structure (ASIC's, FPGA's and the like) or software (DSP's), and can be used in any environment where sampling is possible. The decimation function typically has two objectives, namely reduction of the number of samples and an increase in the accuracy of the samples.

#The invention will now be described in more detail, by way of example only, with reference to the accompanying drawings, in which:

#FIG. 1 is a first embodiment of a prior art decimator;

#FIG. 2 is a second embodiment of a prior art decimator;

#The novel decimator is best explained first in mathematical equivalencies, since these show best illustrate the underlying principles of the invention. A normal decimator over M will perform the following operation:

#Output ⁡ ( N ) = ∑ i = 0 M - 1 ⁢ ⁢ Input ⁡ ( N * M + i ) M

#This means that the output process is M times slower than the input process, and that the output is the average of the last block of M samples.