Defence Science Journal, Vol 43, No 1, January 1993, pp 7-16 @ 1993, DESIDOC Military Radio Communications Research in Australia S.C. Cook., J.B. Scholz and F.B. Andrews Communications Division, Defence Science and Technology Organisation Salisbury, SA 5108, Australia ABSTRACT An overview of recent research by the Australian Defence Science and Technology Organisation in the field of military radio communications is presented. A philosophy for improving digital radio system performance over complex, variable channels is outlined. A key breakthrough, called PDF-directed adaptive radio, which can provide substantially greater throughput over HF channels whilst minimising bit-error rate and delay, is described. Simulation results for fast adaptive schemes applied to both serial-tone and parallel-tone HF modems are presented and shown to significantly out-perform fixed rate modems and modems employing hybrid automatic-repeat-request schemes. A new detector scheme is discussed which has superior performance to conventional detectors for digital traffic in the. presence of inter-symbol interference and impulsive noise. in the uncertainties regarding the future volume, mix and growth rates of these various types of traffic. In this context, it is crucial that Defence radio links and networks should be capable of carrying a widely differing range of traffic with maximum throughput and guaranteed quality of service (QoS). Nowhere is the disclcpa1;1cy between ti)ese future requirements and the performance possible with current conventional technology greater than in the field of HP radio. Although the b.lndwidth constraints at HP will prevent its use for broadband applications, its enduring role in military communications warrants research effort to meet the DORIC goals for this important medium. The key to a breakthrough in this area is a technology which DSTO calls probability density function (PDP) directed adaptive radio. This technology, in which DSTO has made significant advances, promises to yield substantial improvements in military radio communications throughput, reliability and availabilitx, particulary at HP. I t extends to the tactical user the same integration benefits along with efficient, cost-effective use of available transmission assets as are available to users at the fixed core of the military I. INTRODUCTION The Australian Defence Science and Technology Organisation (DSTO) is undertaking significant research which is yielding the possibility of substantial improvements in the performance, robustness and flexibility of military radio communications. This work is being carried out as a key component of the Defence orgaul:)ation integrated communications (DORIC) program which is the flagship of DSTO's military communications R&D activities. DORIC is a major research program aimed at defining and demonstrating an integrated communications architecture for the Australian Defence Organisation into the twenty-first century. This architecture will enable the integration of Defence organisation communications at three levels, namely traffic, Defence networks, and Defence/civil networks integration. The architecture research is centered around the provision of a global backbone for C21 trafIic. Hence, it takes into account the possibilities of transport of large databases, video conferencing, imagery , sensor data and intelligence traffic, in addition to the more traditional Defence traffic and it also factors Received 14 September 1992 7 brought to you by CORE View metadata, citation and similar papers at core.ac.uk provided by Defence Science Journal