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This paper addresses the problem of compensating for motion-induced Doppler frequency offset in multicarrier acoustic communication systems based on orthogonal frequency division multiplexing (OFDM). In mobile acoustic systems, Doppler effect can be sever enough that the received OFDM signal experiences non-negligible frequency offsets even after initial resampling. To target these offsets, a practical...
Chirp slope keying (CSK) modulation based on linear frequency modulation signal (LFM) and hyperbolic frequency modulation signal (HFM) combined with passive time reversal (PTR) for mobile underwater acoustic communication is proposed in this paper. For CSK modulation, the carriers are LFM and HFM signals, and the bit information is represented by different signals. A PTR processor is designed at the...
Mobile phone front-end and baseband modules are hard to obtain on the market for end customers. Thus, software defined radios are widely used in research and development, enabling many opportunities for digital signal processing. In this publication a novel option to receive GSM signals is suggested by using an ultra-low power Sub-GHz transceiver in a legacy mode. The device outputs raw demodulated...
Polar codes were recently chosen to protect the control channel information in the next-generation mobile communication standard (5G) defined by the 3GPP. As a result, receivers will have to implement blind detection of polar coded frames in order to keep complexity, latency, and power consumption tractable. As a newly proposed class of block codes, the problem of polar-code blind detection has received...
In recent years, GPS has been widely used as a positioning system using satellites. However, GPS receivers cannot position calculation their own positions when they can watch less than three Satellites directly. Therefore, in an environment where there are many obstacles such as urban area, there is a problem that it may be not possible to receive four or more GPS signals from GPS satellites. In this...
We investigate the impact of mobility on energy consumption in mobile Ad hoc networks in this paper. Considering a cell-partitioned model of a delay-tolerant mobile ad hoc network with Markovian mobility, we focus on that the communication only occurs in the same cell or the adjacent cell. In this model, we characterize the mobility which have an influence on energy consumption as the nodes' maximum...
Android has a large share in the mobile apps market which makes it attractive for both malicious and good developers. Online apps markets, despite their vetting procedures, still admit malicious apps that could be downloaded mistakenly by mobile users. Detecting Android malwares has been studied by many researchers using different approaches and techniques. The vast majority of them though were focused...
In this paper, the authors proposes a easy calibration of DOD-based BLE beacon system for an indoor localization application. By the proposed calibration method, we can easily recognize the orientation and location of the beacon even though the beacons are roughly installed. The method uses DOD calculated from RSSI of received beacon signals and sensor information of the mobile handset for calibration...
The mobile underwater acoustic channel has brought a great challenge on the encoding and decoding process. The recent development of underwater acoustic processing method aims to get a lower bit error rate(BER). However, the controdiction between lower BER and real-time transmission are not well solved. In this paper, we reach a compromise between them, we combine the turbo code with the adaptive...
Many wireless networks operate in the presence of distance-dependent path–loss in a fading environment with a Poisson interference field. In these networks, the aggregate interference can be modeled as an α-stable process with a known characteristic function. In this study, the authors revisit performance analysis of wireless systems operating in a Nakagamim fading channel. In particular, our emphasis...
Digital dividend refers to the additional vacant spectrum that will be available as a result of transition from analogue to digital terrestrial television broadcasting. Wireless broadband networks such as Long-Term Evolution (LTE) can operate opportunistically in this vacant spectrum by controlling the harmful interference and overheads incurred on licensed users. With the objective of analyzing the...
The paper presents a new wireless communication system using Chirp Spread Spectrum (CSS) transmission. The applied modulation scheme is extended with Pulse Position Modulation (PPM) to transmit data for multiple mobile terminals simultaneously. The proposed system is a Low-Power Wide-Area Network (LPWAN) providing very reliable and robust transmission, especially for terminals moving with high speeds...
Spectral efficiency and capacity of Land Mobile Satellite (LMS) systems can be enhanced by using MIMO (Multiple Input Multiple Output). Polarization diversity is an efficient technique to realize MIMO in LMS communications. Polarization diversity employs different polarization to realize multiple independent propagation paths. Dual polarized antennas offer a space and cost effective alternative compared...
Pose estimation systems have seen some big developments in the last two decades due to technological advances and a greater need for these systems. The industry that thrives and simultaneously popularizes these developments is the entertainment industry. One of the latest developments in home entertainment are Virtual Reality systems that lets users have an immersive experience when playing video...
After five and a half years construction, the main structure of Five-hundred-meter Aperture Spherical radio Telescope (FAST) has been completed in September 2016. Meanwhile, a Radio Quiet Zone (RQZ) with radius 30 km has also been established. In order to evaluate the Radio Frequency Interference (RFI) influence from the mobile base stations within radius 5 km (the restriction zone of RQZ) around...
Solar energy is slated to drive a sustainable future of clean and renewable energy sources. Efficient solar tracking is necessary to achieve acceptable power output per unit incident solar radiation from photovoltaic cells. This paper proposes a GPS based solar tracking system, which has been prototyped on the FRDM-KL25Z (based on the ARM Cortex M0+ MCU) platform by NXP. A significant part of the...
Molecular communication via diffusion (MCvD) is a new research area that considers the communication using messenger molecules in a diffusive fluidic channel. In this area, various modulation methods have been proposed to overcome the problems in the channel, especially the inter symbol interference (ISI). However, these methods are generally considered and tested for the channels that do not change...
This paper investigates direct beamformer estimation in dynamic time division duplexing (TDD) system with the objective of weighted sum rate maximization. For a given TDD frame, base stations (BS) are allocated to either uplink or downlink based on the instantaneous traffic state. The weighted sum mean-squared error minimization framework is used to obtain the decentralized iterative solution for...
This article focuses on the utilization of a mobile robot as data mule for collecting and transferring data from a ground wireless sensor system (WSN). For the case, where the nodes' communication is impeded either due to a non-connected node, or due to excessive retransmissions caused by significant packet losses, the effective transmission rate is reduced and the energy consumption for the RF-communication...
Licensed-Assisted Access Long-Term Evolution (LAA- LTE) framework can offload excessive data stream to the unlicensed spectrum. Devices from different operators will compete for the same band and have to endure a more complex and congested channel conditions. Therefore a rapid and efficient access mechanism should be introduced in the LAA framework. Based on the Type B LBT channel access scheme, this...
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