A maximum entropy method for lightwave system performance evaluation

A constrained maximum entropy criterion is used to approximate the cumulative distribution function of the photocurrent generated by an avalanche photodiode in response to an incident information-bearing optical signal. The approximate distribution, derived from known moments of the photocurrent, is used to evaluate the probability of error in direct detection lightwave systems. In this application, the results of the maximum entropy method are equivalent to those of a Gauss quadrature rule method. However the maximum entropy method exhibits a relative efficiency in terms of the required number of moments of the photocurrent.