An evaluation of the Gaussian approximation technique applied to the multiple input signal case of an ideal hard-limiter

The accuracy of the Gaussian approximation technique (GAT) is evaluated. The GAT involves representing the signal ensemble input into a nonlinear device, such as a hard limiter, as a Gaussian process. The results demonstrate that if the number of signals is greater than five and the power of each of the Gaussian approximated input signals contain less than 20% of the total power, then the results obtained by approximating the input signal ensemble by a Gaussian process will accurately represent actual system performance. It is also shown that the GAT is quite accurate as long as the ratio of Gaussian approximated input signal power to total signal power is no more than 50%