53 research outputs found
Green inter-cluster interference management in uplink of multi-cell processing systems
This paper examines the uplink of cellular systems employing base station cooperation for joint signal processing. We consider clustered cooperation and investigate effective techniques for managing inter-cluster interference to improve users' performance in terms of both spectral and energy efficiency. We use information theoretic analysis to establish general closed form expressions for the system achievable sum rate and the users' Bit-per-Joule capacity while adopting a realistic user device power consumption model. Two main inter-cluster interference management approaches are identified and studied, i.e., through: 1) spectrum re-use; and 2) users' power control. For the former case, we show that isolating clusters by orthogonal resource allocation is the best strategy. For the latter case, we introduce a mathematically tractable user power control scheme and observe that a green opportunistic transmission strategy can significantly reduce the adverse effects of inter-cluster interference while exploiting the benefits from cooperation. To compare the different approaches in the context of real-world systems and evaluate the effect of key design parameters on the users' energy-spectral efficiency relationship, we fit the analytical expressions into a practical macrocell scenario. Our results demonstrate that significant improvement in terms of both energy and spectral efficiency can be achieved by energy-aware interference management
5G green cellular networks considering power allocation schemes
It is important to assess the effect of transmit power allocation schemes on
the energy consumption on random cellular networks. The energy efficiency of 5G
green cellular networks with average and water-filling power allocation schemes
is studied in this paper. Based on the proposed interference and achievable
rate model, an energy efficiency model is proposed for MIMO random cellular
networks. Furthermore, the energy efficiency with average and water-filling
power allocation schemes are presented, respectively. Numerical results
indicate that the maximum limits of energy efficiency are always there for MIMO
random cellular networks with different intensity ratios of mobile stations
(MSs) to base stations (BSs) and channel conditions. Compared with the average
power allocation scheme, the water-filling scheme is shown to improve the
energy efficiency of MIMO random cellular networks when channel state
information (CSI) is attainable for both transmitters and receivers.Comment: 14 pages, 7 figure
RF Energy Harvesting Enabled Power Sharing in Relay Networks
Through simultaneous energy and information transfer, radio frequency (RF)
energy harvesting (EH) reduces the energy consumption of the wireless networks.
It also provides a new approach for the wireless devices to share each other's
energy storage, without relying on the power grid or traffic offloading. In
this paper, we study RF energy harvesting enabled power balancing within the
decode-and-forward (DF) relaying-enhanced cooperative wireless system. An
optimal power allocation policy is proposed for the scenario where both source
and relay nodes can draw power from the radio frequency signals transmitted by
each other. To maximize the overall throughput while meeting the energy
constraints imposed by the RF sources, an optimization problem is formulated
and solved. Based on different harvesting efficiency and channel condition,
closed form solutions for optimal joint source and relay power allocation are
derived.Comment: An abbreviated version will be presented at IEEE online GreenComm,
Nov., 201
Optimal Cooperative Power Allocation for Energy Harvesting Enabled Relay Networks
In this paper, we present a new power allocation scheme for a
decode-and-forward (DF) relaying-enhanced cooperative wireless system. While
both source and relay nodes may have limited traditional brown power supply or
fixed green energy storage, the hybrid source node can also draw power from the
surrounding radio frequency (RF) signals. In particular, we assume a
deterministic RF energy harvesting (EH) model under which the signals
transmitted by the relay serve as the renewable energy source for the source
node. The amount of harvested energy is known for a given transmission power of
the forwarding signal and channel condition between the source and relay nodes.
To maximize the overall throughput while meeting the constraints imposed by the
non-sustainable energy sources and the renewable energy source, an optimization
problem is formulated and solved. Based on different harvesting efficiency and
channel condition, closed form solutions are derived to obtain the optimal
source and relay power allocation jointly. It is shown that instead of
demanding high on-grid power supply or high green energy availability, the
system can achieve compatible or higher throughput by utilizing the harvested
energy
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