65,961 research outputs found
User Cooperation in Wireless Powered Communication Networks
This paper studies user cooperation in the emerging wireless powered
communication network (WPCN) for throughput optimization. For the purpose of
exposition, we consider a two-user WPCN, in which one hybrid access point
(H-AP) broadcasts wireless energy to two distributed users in the downlink (DL)
and the users transmit their independent information using their individually
harvested energy to the H-AP in the uplink (UL) through
time-division-multiple-access (TDMA). We propose user cooperation in the WPCN
where the user which is nearer to the H-AP and has a better channel for DL
energy harvesting and UL information transmission uses part of its allocated UL
time and DL harvested energy to help to relay the far user's information to the
H-AP, in order to achieve more balanced throughput optimization. We maximize
the weighted sum-rate (WSR) of the two users by jointly optimizing the time and
power allocations in the network for both wireless energy transfer in the DL
and wireless information transmission and relaying in the UL. Simulation
results show that the proposed user cooperation scheme can effectively improve
the achievable throughput in the WPCN with desired user fairness.Comment: 7 figure
Cost-Aware Green Cellular Networks with Energy and Communication Cooperation
Energy cost of cellular networks is ever-increasing to match the surge of
wireless data traffic, and the saving of this cost is important to reduce the
operational expenditure (OPEX) of wireless operators in future. The recent
advancements of renewable energy integration and two-way energy flow in smart
grid provide potential new solutions to save the cost. However, they also
impose challenges, especially on how to use the stochastically and spatially
distributed renewable energy harvested at cellular base stations (BSs) to
reliably supply time- and space-varying wireless traffic over cellular
networks. To overcome these challenges, in this article we present three
approaches, namely, {\emph{energy cooperation, communication cooperation, and
joint energy and communication cooperation}}, in which different BSs
bidirectionally trade or share energy via the aggregator in smart grid, and/or
share wireless resources and shift loads with each other to reduce the total
energy cost.Comment: Submitted for possible publicatio
Outage Probability Analysis of Coded Cooperative Communication
Cooperative communication was proposed for wireless networks such as cellular network and wireless ad-hoc networks to meet the rapid increase in the data rate. Coded cooperative communication is one of the co-operative system, in which cooperation is combined with the channel coding. Coded cooperation is a promising technology to improve the outage performance of the system
Energy Efficiency of Network Cooperation for Cellular Uplink Transmissions
There is a growing interest in energy efficient or so-called "green" wireless
communication to reduce the energy consumption in cellular networks. Since
today's wireless terminals are typically equipped with multiple network access
interfaces such as Bluetooth, Wi-Fi, and cellular networks, this paper
investigates user terminals cooperating with each other in transmitting their
data packets to a base station (BS) by exploiting the multiple network access
interfaces, referred to as inter-network cooperation, to improve the energy
efficiency in cellular uplink transmission. Given target outage probability and
data rate requirements, we develop a closed-form expression of energy
efficiency in Bits-per-Joule for the inter-network cooperation by taking into
account the path loss, fading, and thermal noise effects. Numerical results
show that when the cooperating users move towards to each other, the proposed
inter-network cooperation significantly improves the energy efficiency as
compared with the traditional non-cooperation and intra-network cooperation.
This implies that given a certain amount of bits to be transmitted, the
inter-network cooperation requires less energy than the traditional
non-cooperation and intra-network cooperation, showing the energy saving
benefit of inter-network cooperation.Comment: in Proceedings of the 2013 IEEE International Conference on
Communications (IEEE ICC 2013), Budapest, Hungary, June 201
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