13,785 research outputs found
Energy-Efficient Multi-View Video Transmission with View Synthesis-Enabled Multicast
Multi-view videos (MVVs) provide immersive viewing experience, at the cost of
heavy load to wireless networks. Except for further improving viewing
experience, view synthesis can create multicast opportunities for efficient
transmission of MVVs in multiuser wireless networks, which has not been
recognized in existing literature. In this paper, we would like to exploit view
synthesis-enabled multicast opportunities for energy-efficient MVV transmission
in a multiuser wireless network. Specifically, we first establish a
mathematical model to characterize the impact of view synthesis on multicast
opportunities and energy consumption. Then, we consider the optimization of
view selection, transmission time and power allocation to minimize the weighted
sum energy consumption for view transmission and synthesis, which is a
challenging mixed discrete-continuous optimization problem. We propose an
algorithm to obtain an optimal solution with reduced computational complexity
by exploiting optimality properties. To further reduce computational
complexity, we also propose two low-complexity algorithms to obtain two
suboptimal solutions, based on continuous relaxation and Difference of Convex
(DC) programming, respectively. Finally, numerical results demonstrate the
advantage of the proposed solutions.Comment: 22 pages, 6 figures, to be published in GLOBECOM 201
On Low-Resolution ADCs in Practical 5G Millimeter-Wave Massive MIMO Systems
Nowadays, millimeter-wave (mmWave) massive multiple-input multiple-output
(MIMO) systems is a favorable candidate for the fifth generation (5G) cellular
systems. However, a key challenge is the high power consumption imposed by its
numerous radio frequency (RF) chains, which may be mitigated by opting for
low-resolution analog-to-digital converters (ADCs), whilst tolerating a
moderate performance loss. In this article, we discuss several important issues
based on the most recent research on mmWave massive MIMO systems relying on
low-resolution ADCs. We discuss the key transceiver design challenges including
channel estimation, signal detector, channel information feedback and transmit
precoding. Furthermore, we introduce a mixed-ADC architecture as an alternative
technique of improving the overall system performance. Finally, the associated
challenges and potential implementations of the practical 5G mmWave massive
MIMO system {with ADC quantizers} are discussed.Comment: to appear in IEEE Communications Magazin
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