Implementation and on-air testing of a 64 kbps wideband HF data waveform

Abstract

Even with advances in the past two decades, data rates on a single 3 kHz HF channel are, at most, 9.6 kbps with forward error correction. In the digitized battlefield, this sharply limits the number and types of services which can be supported over HF. It is shown that in 12 kHz, a prototype waveform developed to take advantage of wider bandwidth channels can provide data rates of up to 38.4 kbps over a wide range of sky-wave channels. The waveform also includes data rates of 48 and 64 kbps that will be operable on a smaller number of sky-wave channels, but which would be expected to provide reliable communications in surface wave channels. On-air testing of the prototype wideband waveform, implemented as a software upgrade to existing modem hardware, has been undertaken over an 1100 km sky-wave link between Cedar Rapids, Iowa and Dallas, Texas. Tests to date have proven successful operation at 38.4 kbps on this link. When receive diversity has been employed on the link, data rates up to 64 kbps have been successfully used on this sky-wave link.