Latest on-air testing of U.S. MIL-STD-188-110C appendix D wideband HF data waveforms

The US MIL-STD-188-110B has been revised to MIL-STD- 188-110C and includes Appendix D defining a family of wideband HF data waveforms supporting bandwidths from 3 kHz to 24 kHz in increments of 3 kHz. This waveform family, designed by engineers at Harris Corporation and Rockwell Collins, extends the high performance serial tone modem technology of the original versions of the standard to wider bandwidths. The wider bandwidths can provide user bit rates up to 120 kbps and allow users the option of selecting the bandwidth and modulation so as to optimize modem performance. This paper provides an overview of the newly standardized wideband HF waveforms and reports on a series of recent on- air tests performed to evaluate the tradeoffs required to utilize the new waveform standard as the basis for a high performance adaptive HF system. Results are presented for recent on-air testing over several different HF links. These include a 160 km Near Vertical Incidence Skywave (NVIS) link, which is representative of common tactical military HF communications scenarios, and a 1,700 km skywave link more representative of a strategic back haul link. Additionally the latest series of on air testing, reported in this paper, specifically addresses the robustness tradeoffs offered by the new suite of wideband waveforms.