2,063 research outputs found
Flexible resource allocation for joint optimization of energy and spectral efficiency in OFDMA multi-cell networks
The radio resource allocation problem is studied, aiming to jointly optimize the energy efficiency (EE) and spectral efficiency (SE) of downlink OFDMA multi-cell networks. Different from existing works on either EE or SE optimization, a novel EE-SE tradeoff (EST) metric, which can capture both the EST relation and the individual cells’ preferences for EE or SE performance, is introduced as the utility function for each base station (BS). Then the joint EE-SE optimization problem is formulated, and an iterative subchannel allocation and power allocation algorithm is proposed. Numerical results show that the proposed algorithm can exploit the EST relation flexibly and optimize the EE and SE simultaneously to meet diverse EE and SE preferences of individual cells.<br/
Can Hardware Distortion Correlation be Neglected When Analyzing Uplink SE in Massive MIMO?
This paper analyzes how the distortion created by hardware impairments in a
multiple-antenna base station affects the uplink spectral efficiency (SE), with
focus on Massive MIMO. The distortion is correlated across the antennas, but
has been often approximated as uncorrelated to facilitate (tractable) SE
analysis. To determine when this approximation is accurate, basic properties of
the distortion correlation are first uncovered. Then, we focus on third-order
non-linearities and prove analytically and numerically that the correlation can
be neglected in the SE analysis when there are many users. In i.i.d. Rayleigh
fading with equal signal-to-noise ratios, this occurs when having five users.Comment: 5 pages, 3 figures, IEEE International Workshop on Signal Processing
Advances in Wireless Communications (SPAWC), 201
Energy Efficiency and Spectral Efficiency Tradeoff in Device-to-Device (D2D) Communications
In this letter, we investigate the tradeoff between energy efficiency (EE)
and spectral efficiency (SE) in device-to-device (D2D) communications
underlaying cellular networks with uplink channel reuse. The resource
allocation problem is modeled as a noncooperative game, in which each user
equipment (UE) is self-interested and wants to maximize its own EE. Given the
SE requirement and maximum transmission power constraints, a distributed
energy-efficient resource allocation algorithm is proposed by exploiting the
properties of the nonlinear fractional programming. The relationships between
the EE and SE tradeoff of the proposed algorithm and system parameters are
analyzed and verified through computer simulations.Comment: 8 pages, 6 figures, long version paper of IEEE Wireless
Communications Letters, accepted for publication. arXiv admin note: text
overlap with arXiv:1405.196
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