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Caching at the small base station (SBS) is apromising architecture to alleviate the highly-loaded wireless video networks. SBS can cache popular video files, thus serves mobile users without going through backhaul connection to the core network and provides content- level offloading. This paper proposes a novel method for the content caching problem that optimizes cache performance. Our proposed algorithm...
Massive multiple-input multiple-output (Massive MIMO) is acknowledged as a key technology for the 5th generation (5G) of wireless communication systems, which theoretically proved to be of higher throughput, better robustness, superior spectrum- and energy- efficiency. A reliable and realistic channel model serves is the enabling foundation for practical design and testing of communication systems...
Low robustness under mobility is the Achilles' heel of the emerging 60 GHz networking technology. Instead of using omni-directional antennas as in existing Wi-Fi/cellular networks, 60 GHz radios communicate via highly-directional links formed by phased-array beam-forming, so as to upgrade wireless link throughput to multi-Gbps. However, user motion causes misalignment between the Tx's and Rx's beam...
Geometry-based stochastic model (GBSM) of multiple input multiple output (MIMO) channel describes the channel impulse response (CIR) in the sense of rays and clusters, which obey the empirical distributions. Thus, the correlation between MIMO sub-channels is not explicitly defined, which makes it difficult for GBSM to predict channel capacity accurately. Facing the increased antenna number of massive...
This paper proposes a novel approach for detecting groups of people that walk “together” (group mobility) as well as the people who walk “alone” (individual movements) using wireless signals. We exploit multiple wireless sniffers to pervasively collect human mobility data from people with mobile devices and identify similarities and the group mobility based on the wireless fingerprints. We propose...
In practical asynchronous physical-layer network coding (PNC) systems, the symbols from multiple transmitters to a common receiver may be misaligned. The good performance of an asynchronous PNC decoder hinges on accurate estimation of the symbol misalignment. This paper puts forth an optimal symbol misalignment estimator that considerably improves the estimation accuracy over prior schemes. Our scheme...
A new (Beaulieu-Xie) fading model was recently proposed to describe line-of-sight and non-line-of-sight components in wireless channels. In this work, we consider both outage probability and error rate performance of selective combining over this new fading channel model with arbitrary channel correlation. Closed-form expressions are obtained for asymptotically tight upper and lower bounds. The analytical...
The correlation between signals received on multiple antennas is a function of the channel(s) between them, and analysis of this is useful for spatial diversity and spatial multiplexing. In this paper we compute the correlations in both the spatial and frequency domains for a classical two-ray channel in a SIMO setting for an air-ground setting. We analyze this for the “pure” (deterministic) two-ray...
Hardware-efficient low-complexity precoding is very important in the downlink of Massive MIMO systems for mitigating interference and optimizing performance. In this paper, we propose a correlation-driven optimized Taylor expansion (CD-OTE) precoding scheme to simplify linear minimum mean square error (MMSE) precoding. In order to simplify the hardware-expensive matrix inversion involved in the linear...
Multi-agent systems (MAS) communicate over a wireless network to coordinate their actions and to report their mission status. Connectivity and system-level performance can be improved by channel gain prediction. We present a distributed Gaussian process regression (GPR) framework for channel prediction in terms of the received power in MAS. The framework combines a Bayesian committee machine with...
Judiciously setting the base station transmit power that matches its deployment environment is a key problem in ultra dense networks and heterogeneous in-building cellular deployments. A unique characteristic of this problem is the tradeoff between sufficient indoor coverage and limited outdoor leakage, which has to be met without explicit knowledge of the environment. In this paper, we address the...
Wireless technologies gain importance in various fields of industrial communication as they facilitate control and data acquisition tasks. In this context, Parallel Sequence Spread Spectrum (PSSS) is a promising new approach. The parametrization of a PSSS system is very flexible and thus can be precisely adapted to the application's requirements. Independent of the PSSS parametrization, the transmission...
The paper subject is the modernization of two mobile wood processing equipment, a debarking and a chipping machine, working at the forest border and used to obtain wood chips for the pulp and paper industry, in order to work in tandem operating mode. Control hardware has been added and original software has been elaborated but with the wireless communications between the two machines established,...
With the rapid deployment of the high speed railway (HSR), the wireless communication in HSR has been one of the indispensable scenarios in the fifth generation (5G) communications. In order to improve the performance of the orthogonal frequency division multiplexing (OFDM) system in the HSR scenarios, we propose an enhanced linear minimum mean square error channel estimation scheme based on multi-path...
Massive Multiple-Input Multiple-Output (MIMO) is an emerging technology for the future 5G wireless communication systems and has been expected to dramatically improve the performance over the years. The main aim of this paper is to investigate the ergodic capacity of the downlink massive Multi-User (MU-MIMO) system under spatially correlated Rayleigh fading channels using two correlative models, namely...
Next generation 5G wireless networks pose several important security challenges. One fundamental challenge is key management between the two communicating parties. The goal is to establish a common secret key through an unsecured wireless medium. In this paper, we introduce a new physical layer paradigm for secure key exchange between the legitimate communication parties in the presence of a passive...
Time-reversal (TR) transmission scheme has attracted more and more attention from both academia and industry due to its ability to focus the energy of a transmitted signal at an intended focal spot, both in the time and spatial domains. Based on the extensive data collected in the real world, we observe that the energy distribution around the focal spot is highly stationary and location-independent,...
A pattern control for portable devices at 2.45 GHz is proposed by exploiting phase-shifted characteristic modes (CMs). Among all available orthogonal CMs, the pattern control of a rectangular conductive plane has been obtained by a weighted linear superposition of only two current modes (J4 and J8). A proper position of two capacitive coupling exciters (CCEs), hosted above the rectangular conductive...
In telecommunication network systems, there are a large number of interconnected components which also contain many subcomponents. Heavy rain, thunder or other factors can cause mal-function of the components or disconnections between the components which trigger alarms. Because of the interconnection of elements, triggered alarms may propagate to other components. This creates harsh challenges to...
In wireless communication systems, frequency-hopping spread spectrum and direct sequence spread spectrum are two main spread coding technologies. Frequency-hopping sequence (FHS) plays an important role in frequency-hopping spread spectrum systems. In this paper, a new class of FHS based on Cyclotomy is constructed. New FHS has new parameters not covered in the literature. It is shown that new FHS...
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