4,424 research outputs found
Energy-Efficient Symbol-Level Precoding in Multiuser MISO Based on Relaxed Detection Region
This paper addresses the problem of exploiting interference among
simultaneous multiuser transmissions in the downlink of multiple-antenna
systems. Using symbol-level precoding, a new approach towards addressing the
multiuser interference is discussed through jointly utilizing the channel state
information (CSI) and data information (DI). The interference among the data
streams is transformed under certain conditions to a useful signal that can
improve the signal-to-interference noise ratio (SINR) of the downlink
transmissions and as a result the system's energy efficiency. In this context,
new constructive interference precoding techniques that tackle the transmit
power minimization (min power) with individual SINR constraints at each user's
receiver have been proposed. In this paper, we generalize the CI precoding
design under the assumption that the received MPSK symbol can reside in a
relaxed region in order to be correctly detected. Moreover, a weighted
maximization of the minimum SNR among all users is studied taking into account
the relaxed detection region. Symbol error rate analysis (SER) for the proposed
precoding is discussed to characterize the tradeoff between transmit power
reduction and SER increase due to the relaxation. Based on this tradeoff, the
energy efficiency performance of the proposed technique is analyzed. Finally,
extensive numerical results show that the proposed schemes outperform other
state-of-the-art techniques.Comment: Submitted to IEEE transactions on Wireless Communications. arXiv
admin note: substantial text overlap with arXiv:1408.470
Energy-Efficient Resource Allocation in Multiuser MIMO Systems: A Game-Theoretic Framework
This paper focuses on the cross-layer issue of resource allocation for energy
efficiency in the uplink of a multiuser MIMO wireless communication system.
Assuming that all of the transmitters and the uplink receiver are equipped with
multiple antennas, the situation considered is that in which each terminal is
allowed to vary its transmit power, beamforming vector, and uplink receiver in
order to maximize its own utility, which is defined as the ratio of data
throughput to transmit power; the case in which non-linear interference
cancellation is used at the receiver is also investigated. Applying a
game-theoretic formulation, several non-cooperative games for utility
maximization are thus formulated, and their performance is compared in terms of
achieved average utility, achieved average SINR and average transmit power at
the Nash equilibrium. Numerical results show that the use of the proposed
cross-layer resource allocation policies brings remarkable advantages to the
network performance.Comment: Proceedings of the 16th European Signal Processing Conference,
Lausanne, Switzerland, August 25-29, 200
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