This paper deals with the use of stochastic resonance (SR) for detection purposes. The nonlinear physical phenomenon of SR generally occurs in dynamical bistable systems excited by a noisy sine: such systems are able to force cooperation between sine and noise such that the noise ampli1es the sine. Because of this non-intuitive e3ect, the use of SR can be envisaged to detect small amplitude sines corrupted by additive noise. In this paper we recall some basics of detection and then show why SR can be used in sine detection context. After recalling some basics of SR in discrete time, we show how to use SR in a detection scheme. ? 2002 Elsevier Science B.V. All rights reserved.