A New HF-Link Parameters/Quality Analysis Approach

HF communication systems operations are characterized by several well-known problems, most of which can be overcome by advances in communications and processing technology. Success is strongly dependent upon selection of the optimum operating frequency and data-transmission configuration, which are highly time and link variable. Described in this paper is a new approach for "real-time" HF-link parameters measurement and quality analysis (LQA) applicable to optimization of high-speed HF data links. The approach employs a digital-signal-processing-based technique for measurement of general HF channel parameters, using simple, in-band test signals, and algorithmic estimation of data-transmission performance for a variety of link configurations. Channel-parameters measurement accuracies are illustrated. Also shown are results of on-the-air HF transmission tests in which LQA-based estimated BER\´s are correlated with measured BER\´s for modems operating over temperate-latitude and transauroral paths. Planned implementations in adaptive systems are described.