Constrained Interference Alignment for Covert Communications over Interference Networks
Abstract
Constrained Interference Alignment for Covert Communications over Interference Networks Syed A. Jafar E-mail: syed@uci.edu Tactical communication networks should ideally operate at the boundary of the tradeo between covert communication capability and spectral e ciency. On the side of spectral e ciency, interference alignment | a radical idea that shows that interference networks are not fundamentally interference limited | is one of the most promising breakthroughs in wireless communications and network information theory over the past decade. On the side of covert communication, digital chaos signaling has produced remarkable improvements against cyclostationary feature detectors and protocol sni ers, and close to ideal anti-jam performance with only modest increases in computation complexity, albeit with a price paid in terms of spectral e ciency. With digital chaos signaling and interference alignment representing the cutting edge of covert communications and spectral e ciency, respectively, using the two in conjunction holds the potential for achieving the best of both worlds | covert communications with high spectral e ciency. However, it is challenging to incorporate interference alignment principles into covert communication networks due to constraints such as robustness, secrecy, anti-jamming, anti-spoo ng, low probability of intercept, and low probability of detection. Exploring the utility of interference alignment within these constraints is the goal of the proposed research. The proposed research is divided into three thrusts, exploring 1) interference alignment with constrained transmitters, 2) interference alignment with constrained receivers, and 3) the tradeo between covertness and spectral e ciency. Within the rst thrust, we explore the constraints on the use of signaling dimensions at the transmitters that arise due to covertness requirements. The use of spread-spectrum techniques, direct sequence as well as frequency hopping, possibly optimized for covertness, is enforced as an external constraint and interference alignment is applied within this constrained framework. The second thrust explores the utility of interference alignment for receivers that are constrained to operate with limited coherence and/or are subject to asynchrony. The third thrust is aimed at understand- ing the nature of the fundamental tradeo between covertness and spectral e ciency from the perspective of both existing schemes (achievability) and information theoretic bounds (converse). The proposed research is supported by preliminary results and insights from the PI s prior work. There are intriguing similarities between direct sequence spread spectrum techniques used for covert communications and the symbol extension techniques used for interference alignment. Dynamic topologies shown to be bene cial for interference alignment in the PI s prior work can arise through slow frequency hopping. Fast frequency hopping adds the intriguing aspect of dynamic interference at the sub-symbol level, which may give rise to weak interference settings studied recently by the PI. Given the signi cance and novelty of these topics, the proposed research is expected to signi cantly advance our understanding of optimal design principles of future covert communication networks.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 12, 2016
- Source ID
- N000141512557
Entities
People
- Syed A. Jafar
Organizations
- Naval Information Warfare Center Pacific
- Office of Naval Research
- United States Navy