Numerical Evaluation of Information Outage for BPSK FHSS Link Performance Analysis

The information outage probability serves as a practical benchmark for the performance evaluation of channel codes in the finite block length region. The metric is derived from the distribution of the mutual information between a channel's in- and output and is readily available for the Gaussian AWGN channel. To review its applicability for modulation constraint channel inputs, we propose a numerical method for the evaluation of the mutual information random variable for BPSK modulated code words. We apply the model to a block fading channel to study the link performance of a frequency hopping spread spectrum (FHSS) system in a slow-fading two-path propagation environment, which is a typical scenario for low power wide area (LPWA) applications. The information outage probability closely reproduces the behavior of a practical rate 1/3 Turbo decoder.