Cognitive Radio for Tactical Wireless Communication Networks

Abstract

The public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Research has been completed on adaptive modulation and coding for multicast transmission in a tactical packet radio network. Our adaptive multicast transmission compensates for changes in propagation conditions that occur from packet to packet during a session with one sender and multiple receivers. We also completed our research investigation of adaptive coding for frequency-hop communications over tactical communications channels that have time-varying fading and partial-band interference. New protocols were developed that combat fading and ABSTRACTResearch has been completed on adaptive modulation and coding for multicast transmission in a tactical packet radio network. Our adaptive multicast transmission compensates for changes in propagation conditions that occur from packet to packet during a session with one sender and multiple receivers. We also completed our research investigation of adaptive coding for frequency-hop communications over tactical communications channels that have time-varying fading and partial-band interference. New protocols were developed that combat fading and interference while providing throughput levels that are near the theoretical upper bounds. New distributed protocols for channel access and adaptive spreading were devised and evaluated for use in direct-sequence spread-spectrum packet radio networks that have no central controllers, access points, or base stations. Information theoretic bounds and tools have been derived that give performance benchmarks for practical protocols, provide analytical techniques for the minimization of resource consumption in tactical networks, and simplify the design of protocols for the adaptation of coding and spreading in direct-sequence spread-spectrum packet radios.