Non-orthogonal multiple access (NOMA) has attracted much recent attention owing to its capability for improving the system spectral efficiency in wireless communications. Deploying NOMA in heterogeneous network can sa...
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The state-of-the-art depth map coding distortion measurement in view synthesis optimization (VSO) of 3D-HEVC reference software applies only for 1D parallel camera arrangement and requires explicit specification of vi...
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The state-of-the-art depth map coding distortion measurement in view synthesis optimization (VSO) of 3D-HEVC reference software applies only for 1D parallel camera arrangement and requires explicit specification of virtual camera position(s) to be optimized. This paper presents a general joint distortion metric (GJDM) of synthesized views for depth map coding of FTV. The proposed metric estimates the expected distortion of all potential synthesized views generated by the depth map regardless of the arrangement of virtual cameras, thus supports arbitrary camera setups and various applications, e.g., free navigation. Furthermore, the proposed distortion metric is rendering-free and prone to parallelization. In a word, the proposed metric supports more general camera arrangement and achieves 21% coding gain and 6% encoding time reduction in average in free navigation test sequences.
This paper considers a wirelessly powered wiretap channel, where an energy constrained information source, powered by a dedicated power beacon, communicates with a legitimate user in the presence of a passive eavesdro...
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ISBN:
(纸本)9781509018918
This paper considers a wirelessly powered wiretap channel, where an energy constrained information source, powered by a dedicated power beacon, communicates with a legitimate user in the presence of a passive eavesdropper. The source is assumed to have multiple antennas, while the other three nodes are equipped with a single antenna each. Considering a simple time-switching design where power transfer and information transmission are separated in time. We investigate two popular transmission schemes, namely maximum ratio transmission (MRT) and transmit antenna selection (TAS). Closed-form expressions are derived for the achievable secrecy outage probability of both schemes. In addition, simple approximations are obtained at the high signal-to-noise ratio (SNR) regime. Our results demonstrate that the more channel state information (CSI) available, the better the secrecy performance. For instance, with full CSI of the main channel, the system can achieve substantial secrecy diversity gain. On the other hand, without the CSI of the main channel, no diversity gain can be attained. Finally, our theoretical claims are validated by the numerical results.
Traditional mobile data offloading transfers cellular users to WiFi networks to relieve the cellular system from the pressure of the ever-increasing data traffic load. However, the spectrum utilization of the WiFi net...
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A general approach is established for deriving one-shot performance bounds for information-theoretic problems on general alphabets beyond countable alphabets. It is mainly based on the quantization idea and a novel fo...
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ISBN:
(纸本)9781509028610
A general approach is established for deriving one-shot performance bounds for information-theoretic problems on general alphabets beyond countable alphabets. It is mainly based on the quantization idea and a novel form of “likelihood ratio”. As an example, one-shot lower and upper bounds for random number generation from correlated sources on general alphabets are derived.
In this paper, we consider a network where an access point (AP) wirelessly transfers energy to user equipments (UEs) and UEs use the harvested energy to communicate with the AP. Due to different radio propagation loss...
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ISBN:
(纸本)9781509017508
In this paper, we consider a network where an access point (AP) wirelessly transfers energy to user equipments (UEs) and UEs use the harvested energy to communicate with the AP. Due to different radio propagation losses, the UEs far from the AP harvest little but consume much, thus suffering high transmission delay, while the UEs close to the AP has redundant energy. To reduce the average delay, we propose an adaptive harvest-then-cooperate (AHC) protocol, where every UE sends data to the AP directly or via other UEs acting as relays in a time-division multiplexing manner. Based on the load and energy distributions, the AP controls the transmit power and routing topology to minimize the average delay. To avoid data overflow in UE relays, we propose a method generating scheduling schemes given the transmit power and the routing topology. The average delay minimization is approximately modeled as a Markov decision process, and a policy iteration algorithm is employed to obtain the optimal combination of the power and the routing. Simulation results demonstrate the effectiveness of the AHC protocol in the delay minimization and reveal that the protocol can relieve the unbalance of the energy distribution.
Geometry-based optimal power control was proposed in [14] to transform the power-control problem to a new geometrical problem on the position relationship between a line and some points. This scheme provides a novel v...
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