Distribution of the sum of two sine waves and Gaussian noise

The cumulative distribution of the envelope of the sum of two sine waves and narrowband Gaussian noise, the difference of the phases of the sine waves being uniformly distributed over (0, 2 pi ), is expressed as an integral that is evaluated by numerical quadrature. Approximation for the distribution valid in the limit of large signal-to-noise ratio are derived. The probability density function of the envelope is similarly treated.<
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