Comments on "Degradation of signal-to-noise ratio due to amplitude ripple

Sadr, Shahshahani, and Hurd (see ibid., vol.35, no.4, p.874, 1989) studied the effect of filtering on the signal-to-noise ratio (SNR) of a coherently demodulated bandlimited signal and found the worst case amplitude ripple. They showed that when the maximum passband amplitude ripple is 2/spl Delta/, then the signal-to-noise ratio is degraded by at most (1-/spl Delta//sup 2/). A very simple proof is given in this article.<
>