A new wideband high frequency channel simulation system

This paper provides a technical overview of a high frequency (HF) channel simulation system that is applicable to either narrowband or wideband HF channels. Although narrowband models of the HF channel have existed for many years, they are applicable only to a limited set of actual narrowband channel conditions. The need for an HF channel model that is valid for both narrow and wide bandwidths over a more extensive range of channel conditions motivated the research reported in this paper. Wideband propagation, noise, and interference models have been developed and implemented in a real-time digital simulator that utilizes state-of-the-art signal processing hardware with a throughput in excess of 1 mega samples/s. The simulator architecture has the flexibility to permit its application to future simulator designs as faster signal processing components become available. The current simulation system can be used for simulating radio channels other than HF because the propagation, noise, and interference models are implemented in software. This flexibility results in a very powerful test instrument.