HF Radio Communication Systems Design Assessment. Task 3.3i. Link Quality Analysis (LQA)

摘要

Link quality analysis (LQA) or in-band channel evaluation is a microscopic approach to characterizing HF radio channels for a two-point system(s). Wide band spectrum monitoring and oblique sounding (step or linear FM) are examples of macroscopic approaches whereby propagation and noise characterization are conducted in a gross sense. Chirp sounding (Section 4.2), however, has such good resolution capabilities that distinctions between frequencies of varying multipath structure can be easily performed. Enhanced frequency selection and communication system performance estimation/projection can be achieved from LQA, permitting higher reliability and throughput of data. A fundamental approach to channel evaluation has been proposed. Estimation of the a priori channel transfer function and the noise power density spectrum is viewed as essential for statistically describing the HF radio channel. Furthermore, this fundamental information can be used to estimate analog/digital system performance based on known system constraints, rate parameters, and coding/modulation schemes.