2,420 research outputs found
Generalized Interference Alignment --- Part I: Theoretical Framework
Interference alignment (IA) has attracted enormous research interest as it
achieves optimal capacity scaling with respect to signal to noise ratio on
interference networks. IA has also recently emerged as an effective tool in
engineering interference for secrecy protection on wireless wiretap networks.
However, despite the numerous works dedicated to IA, two of its fundamental
issues, i.e., feasibility conditions and transceiver design, are not completely
addressed in the literature. In this two part paper, a generalised interference
alignment (GIA) technique is proposed to enhance the IA's capability in secrecy
protection. A theoretical framework is established to analyze the two
fundamental issues of GIA in Part I and then the performance of GIA in
large-scale stochastic networks is characterized to illustrate how GIA benefits
secrecy protection in Part II. The theoretical framework for GIA adopts
methodologies from algebraic geometry, determines the necessary and sufficient
feasibility conditions of GIA, and generates a set of algorithms that can solve
the GIA problem. This framework sets up a foundation for the development and
implementation of GIA.Comment: Minor Revision at IEEE Transactions on Signal Processin
On the Throughput Cost of Physical Layer Security in Decentralized Wireless Networks
This paper studies the throughput of large-scale decentralized wireless
networks with physical layer security constraints. In particular, we are
interested in the question of how much throughput needs to be sacrificed for
achieving a certain level of security. We consider random networks where the
legitimate nodes and the eavesdroppers are distributed according to independent
two-dimensional Poisson point processes. The transmission capacity framework is
used to characterize the area spectral efficiency of secure transmissions with
constraints on both the quality of service (QoS) and the level of security.
This framework illustrates the dependence of the network throughput on key
system parameters, such as the densities of legitimate nodes and eavesdroppers,
as well as the QoS and security constraints. One important finding is that the
throughput cost of achieving a moderate level of security is quite low, while
throughput must be significantly sacrificed to realize a highly secure network.
We also study the use of a secrecy guard zone, which is shown to give a
significant improvement on the throughput of networks with high security
requirements.Comment: Accepted for publication in IEEE Transactions on Wireless
Communication
Multiuser Diversity for Secrecy Communications Using Opportunistic Jammer Selection -- Secure DoF and Jammer Scaling Law
In this paper, we propose opportunistic jammer selection in a wireless
security system for increasing the secure degrees of freedom (DoF) between a
transmitter and a legitimate receiver (say, Alice and Bob). There is a jammer
group consisting of jammers among which Bob selects jammers. The
selected jammers transmit independent and identically distributed Gaussian
signals to hinder the eavesdropper (Eve). Since the channels of Bob and Eve are
independent, we can select the jammers whose jamming channels are aligned at
Bob, but not at Eve. As a result, Eve cannot obtain any DoF unless it has more
than receive antennas, where is the number of jammer's transmit
antenna each, and hence can be regarded as defensible dimensions against
Eve. For the jamming signal alignment at Bob, we propose two opportunistic
jammer selection schemes and find the scaling law of the required number of
jammers for target secure DoF by a geometrical interpretation of the received
signals.Comment: Accepted with minor revisions, IEEE Trans. on Signal Processin
- …