SPECTRUM EFFICIENT A / J WAVEFORM FOR 21 st CENTURY HF

The concept of spectrum eficient, Paul K. Lee, Jeffrey A. Rudin Sanders, A Lockheed Martin Company PTP1-2C39, P. O. BOX 868 Nashua, NH 03061 anti-jam (A/J), high @equency (HF) communications is discussed in this paper. The HF concept is intended for mobile, beyond line qf sight (BLOS) military communications for use in the 21st century. Spectrum ef>ciency and fast jiequency hopping ofler opportunities for high data rates and A/J capability. This system concept is referred to as HF_dt_21. The concept employs a new high densi~ modulation waveform discrete trellis-coded modulation (d-TC~, Reed-Solomon code, and fast jiequency hopping (3 or 6 kilohops/s), to achieve: high spectrum eficiency, frequency reuse, and A/J. These features are desirable for future Army tactical communications, but unachievable in a single system with current HF technolo~. Technical feasibility and system performance are also presented herein.