ASYMPTOTIC DISTORTION SPECTRUM OF CLIPPED, DC-BIASED, GAUSSIAN-NOISE

Consider a zero-mean, stationary Gaussian process g(t), to which a large positive constant A has been added. Define a distortion process h(A)(t) as equal to g(t) + A when the latter is negative and equal to zero otherwise. Here we calculate the power spectrum of the process h(A)(t) asymptotically as A becomes large. The results have application for estimating the nonlinear-distortion power in the recovered signal when many frequency-multiplexed subcarriers collectively modulate a laser's output power, as would be the case for CATV transmission over an optical fiber. The process h(A)(t) then models the nonlinear distortion caused by occasional clipping of the dc-biased laser input.