4,383 research outputs found
Cognitive and Energy Harvesting-Based D2D Communication in Cellular Networks: Stochastic Geometry Modeling and Analysis
While cognitive radio enables spectrum-efficient wireless communication,
radio frequency (RF) energy harvesting from ambient interference is an enabler
for energy-efficient wireless communication. In this paper, we model and
analyze cognitive and energy harvesting-based D2D communication in cellular
networks. The cognitive D2D transmitters harvest energy from ambient
interference and use one of the channels allocated to cellular users (in uplink
or downlink), which is referred to as the D2D channel, to communicate with the
corresponding receivers. We investigate two spectrum access policies for
cellular communication in the uplink or downlink, namely, random spectrum
access (RSA) policy and prioritized spectrum access (PSA) policy. In RSA, any
of the available channels including the channel used by the D2D transmitters
can be selected randomly for cellular communication, while in PSA the D2D
channel is used only when all of the other channels are occupied. A D2D
transmitter can communicate successfully with its receiver only when it
harvests enough energy to perform channel inversion toward the receiver, the
D2D channel is free, and the at the receiver is above the
required threshold; otherwise, an outage occurs for the D2D communication. We
use tools from stochastic geometry to evaluate the performance of the proposed
communication system model with general path-loss exponent in terms of outage
probability for D2D and cellular users. We show that energy harvesting can be a
reliable alternative to power cognitive D2D transmitters while achieving
acceptable performance. Under the same outage requirements as
for the non-cognitive case, cognitive channel access improves the outage
probability for D2D users for both the spectrum access policies.Comment: IEEE Transactions on Communications, to appea
Network-Assisted Device-to-Device (D2D) Direct Proximity Discovery with Underlay Communication
Device-to-Device communications are expected to play an important role in
current and future cellular generations, by increasing the spatial reuse of
spectrum resources and enabling lower latency communication links. This
paradigm has two fundamental building blocks: (i) proximity discovery and (ii)
direct communication between proximate devices. While (ii) is treated
extensively in the recent literature, (i) has received relatively little
attention. In this paper we analyze a network-assisted underlay proximity
discovery protocol, where a cellular device can take the role of: announcer
(which announces its interest in establishing a D2D connection) or monitor
(which listens for the transmissions from the announcers). Traditionally, the
announcers transmit their messages over dedicated channel resources. In
contrast, inspired by recent advances on receivers with multiuser decoding
capabilities, we consider the case where the announcers underlay their messages
in the downlink transmissions that are directed towards the monitoring devices.
We propose a power control scheme applied to the downlink transmission, which
copes with the underlay transmission via additional power expenditure, while
guaranteeing both reliable downlink transmissions and underlay proximity
discovery.Comment: Accepted for presentation at Globecom 201
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