DSP Blockset

Overlapping Buffers.   In some cases it is useful to work with data that represents overlapping sections of an original sample-based or frame-based signal. In estimating the power spectrum of a signal, for example, it is often desirable to compute the FFT of overlapping sections of data. Overlapping buffers are also needed in computing statistics on a sliding window, or for adaptive filtering. The Buffer overlap parameter of the Buffer block specifies the number of overlap points, L.

In the overlap case (L > 0), the frame period for the output is (Mo-L)*Tsi, where Tsi is the input sample period and Mo is the Buffer size.

Note    Set the Buffer overlap parameter to a negative value to achieve output frame rates slower than in the nonoverlapping case. The output frame period is still Tsi*(Mo-L), but now with L < 0. Only the Mo newest inputs are included in the output buffer; the previous L inputs are discarded.

Example: Buffering Sample-Based Signals without Overlap

Example: Buffering Sample-Based Signals with Overlap