I have a signal of length 'N' which looks like this
[.......p-set...] [SINE-WAVE] [....q-set...]
amplitude of points in p-set << amplitude of points in sine-wave
Sometimes there are a few sparse points in p-set whose amplitude is comparable to sine-wave points. However, number of such points is much less than the length of the sine wave. I want to find the beginning point of the sine-wave.
Clearly I cannot use thersholding as those sparse points will be counted as the beginning of the sine-wave which is wrong.
Is there any effective solution or existing functions? Sliding window may be? Please explain with some code (MATLAB). Due to firewall restrictions I cannot upload image. Sorry.