Document Type



Available under a Creative Commons Attribution Non-Commercial Share Alike 4.0 International Licence


Applied mathematics

Publication Details

ISAST Transactions on Electronics and Signal Processing, vol: ISSN 1797-2329, issue: No. 1, Vol. 1, pages: 61 - 71, 2007


This paper discusses a new approach to ‘watermarking’ digital signals using linear frequency modulated or ‘chirp’ coding. The principles underlying this approach are based on the use of a matched filter to provide a reconstruction of a chirped code that is uniquely robust, i.e. in the case of very low signal-to-noise ratios.

Chirp coding for authenticating data is generic in the sense that it can be used for a range of data types and applications (the authentication of speech and audio signals, for example). The theoretical and computational aspects of the matched filter and the properties of a chirp are revisited to provide the essential background to the method. Signal code generating schemes are then addressed and details of the coding and decoding techniques considered.