6,039 research outputs found
Dynamic Interference Management
A linear interference network is considered. Long-term fluctuations (shadow
fading) in the wireless channel can lead to any link being erased with
probability p. Each receiver is interested in one unique message that can be
available at M transmitters. In a cellular downlink scenario, the case where
M=1 reflects the cell association problem, and the case where M>1 reflects the
problem of setting up the backhaul links for Coordinated Multi-Point (CoMP)
transmission. In both cases, we analyze Degrees of Freedom (DoF) optimal
schemes for the case of no erasures, and propose new schemes with better
average DoF performance at high probabilities of erasure. For M=1, we
characterize the average per user DoF, and identify the optimal assignment of
messages to transmitters at each value of p. For general values of M, we show
that there is no strategy for assigning messages to transmitters in large
networks that is optimal for all values of p.Comment: Shorter version is in proceedings of the Asilomar Conference on
Signals, Systems, and Computers, Nov. 201
Multilevel Topological Interference Management
The robust principles of treating interference as noise (TIN) when it is
sufficiently weak, and avoiding it when it is not, form the background for this
work. Combining TIN with the topological interference management (TIM)
framework that identifies optimal interference avoidance schemes, a baseline
TIM-TIN approach is proposed which decomposes a network into TIN and TIM
components, allocates the signal power levels to each user in the TIN
component, allocates signal vector space dimensions to each user in the TIM
component, and guarantees that the product of the two is an achievable number
of signal dimensions available to each user in the original network.Comment: To be presented at 2013 IEEE Information Theory Worksho
Topological Interference Management with Alternating Connectivity
The topological interference management problem refers to the study of the
capacity of partially connected linear (wired and wireless) communication
networks with no channel state information at the transmitters (no CSIT) beyond
the network topology, i.e., a knowledge of which channel coefficients are zero
(weaker than the noise floor in the wireless case). While the problem is
originally studied with fixed topology, in this work we explore the
implications of varying connectivity, through a series of simple and
conceptually representative examples. Specifically, we highlight the
synergistic benefits of coding across alternating topologies
Opportunistic Interference Management for Multicarrier systems
We study opportunistic interference management when there is bursty
interference in parallel 2-user linear deterministic interference channels. A
degraded message set communication problem is formulated to exploit the
burstiness of interference in M subcarriers allocated to each user. We focus on
symmetric rate requirements based on the number of interfered subcarriers
rather than the exact set of interfered subcarriers. Inner bounds are obtained
using erasure coding, signal-scale alignment and Han-Kobayashi coding strategy.
Tight outer bounds for a variety of regimes are obtained using the El
Gamal-Costa injective interference channel bounds and a sliding window subset
entropy inequality. The result demonstrates an application of techniques from
multilevel diversity coding to interference channels. We also conjecture outer
bounds indicating the sub-optimality of erasure coding across subcarriers in
certain regimes.Comment: 8 pages, 5 figures, a shorter version of this work will appear in the
proceedings of ISIT 201
Inter-cell Interference Management in DL/UL PHY Control for IEEE802.16m
[[abstract]]Some interference management measures in the PHY control to reduce possible interferences in the transmission between an MS and BSs are proposed. The design and assignment procedures to generate pilots to have lower interference levels are introduced and discussed. Based on the design process each pilot is accordingly assigned an interference weight with respect to a basic pilot and with this design in the system simulation by utilizing the generated pilots to IEEE 802.16m system it reveals that the system performance has 7.5 dB and 23 dB advantages in the interference levels for 7 BSs and 19 BSs respectively comparing with the conventional pilot design that assigns the pilots with the same interference weight for all BSs.[[conferencetype]]國際[[conferencedate]]20090709~20090710[[iscallforpapers]]Y[[conferencelocation]]California, US
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