Distance distribution for turbo-equalized systems over static frequency-selective channels

In this paper we investigate the Euclidean distance distribution in turbo-equalized systems over static frequency-selective (ISI) channels (1). We propose a novel approach in evaluating the squared Euclidean distance between transmitted sequences at the output of the ISI channel based on the correlogram of error sequences. By inspecting autocorrelation properties of error sequences, we derive the main statistics of the output Euclidean distance. The proposed method provides a more comprehensive tool to predict system behavior with finite or infinite packet length. We exploit obtained results to evaluate the frame error rate (FER) performance of the system under maximum-likelihood sequence estimation.