Interference multiple access wireless network demonstration enabled by real-time multiuser detection
ABSTRACT In recent outdoor, over-the-air tests and simulations, DARPA demonstrated greater than 3X improvement in aggregate wireless network throughput and latency compared to the 802.11b wireless local area network. This achievement is based on allowing multiple users to simultaneously use the same channel (time, frequency, code, etc.) without requiring a centralized infrastructure for coordination and spectrum preplanning. DARPA has developed new multi-user detection (MUD) algorithms that make it possible to exploit multi-access interference to increase network capacity. A key program goal is to apply these algorithms to next-generation warfighter communications systems for substantial capacity, latency and scalability improvements.
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ABSTRACT: Underlay communications has the potential to become a valuable tool for increasing the capacity of spectrum provided that the quality of communications is upheld. In this paper, we propose a method for underlay nodes to detect, and coordinate with, other underlay nodes to form a network on preoccupied spectrum. Specifically, we introduce a novel optimization algorithm, called the Coordinated Optimization of EXposure Introduced by a Secondary Transmitter (COEXIST), which selects the best communications channel for all nodes within a network while minimizing interference with the primary user. This algorithm does not require knowledge of spatial location of the primary users or underlay nodes. With the proposed solution, underlay nodes can detect other nodes at power levels far below the power level of the primary user and, once a network is formed, nodes can continue to communicate at very low power levels without causing interference to primary users transmitting at the same time.Global Communications Conference (GLOBECOM), 2012 IEEE; 01/2012
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ABSTRACT: Multiuser Detection (MUD) based receivers theoretically require no power control (PC) as they have the ability to separate signals regardless of their relative power levels as long as these signals achieve a suitable SNR. In practice, receiver designs have finite dynamic range. In this paper, power aware scheduling (PAS) and power control (PC) algorithms are investigated to address the finite MUD dynamic range and performance results are shown. The final PAS algorithm and motivating factors behind the design selections made on the DARPA Interference Multiple Access (DIMA) program are highlighted as well as different approaches involving both scheduling and PC. The techniques selected on the DIMA program are currently operating as part of the DEVIA mobile real-time experiments.01/2010;
Conference Paper: Application of multiuser detection to the common data link waveform[Show abstract] [Hide abstract]
ABSTRACT: The growing use of small form factor unmanned aerial systems (UAS) in theater presents severe co-channel interference issues with todaypsilas radio technology. This paper addresses this concern by describing multiuser detection receiver technology and its application to the Common Data Link (CDL) ISR waveform protocol. By equipping CDL radios with MUD receiver technology developed under the DARPA Interference Multiple Access Communications Program, we show a significant reduction in spectrum pre planning requirements and increases in spectral efficiency. This technique enables multiple UASs to occupy the same channel at the same time without centralized coordination or power control.Military Communications Conference, 2008. MILCOM 2008. IEEE; 12/2008