Enhancement of time compression overlap-add using multirate downsample upsample shift add algorithm

Abstract

In this paper, we introduce a Downsample Upsample Shift Add (DUSA) method that faithfully implements the Time Compression Overlap-Add (TC-OLA) technique while overcoming some of the existing TC-OLA implementation shortcomings. The mathematical framework of DUSA relies on three operators: downsample, upsample, shift and add operators, and is shown to yield the same results as TC-OLA. Moreover, at some point of the processing of DUSA is carried out at a lower sampling rate which partially decreases the complexity of the design. Furthermore, DUSA does not depend on the window function and inherently accommodates any values of the TC-OLA parameters, namely the segment length, M, and the hoping size, R. Finally, DUSA can be easily extended to implement other schemes such as CDMA.