Real-Time Software Simulation of the HF Radio Channel

Modern array processor and digital signal processing technologies have been applied to develop a real-time, software-based system that simulates high-frequency (HF) radio links. This system is called an HF Channel Simulator. In this paper we describe the design features and performance of one such simulator, based on the Floating Point Systems AP-120B array processor. The simulator characteristics are a 4 kHz signal bandwidth and a great flexibility in the selection of link parameters available to the user. All distortions are at least 50 dB below the desired signal output level.