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In this paper, an algorithm for accurate distance estimation of a vehicle to a road side unit (RSU) in urban multipath environments is presented. The algorithm is based on spatial filtering using a uniform circular array (UCA) antenna and a cross correlation based time delay detection. The time base for the cross correlation is built using Global Navigation Satellite System (GNSS) based positioning...
In this paper we introduce an improvement of the symbol request sharing (SRS) cooperative scheme, namely the adaptive SRS (A-SRS). Both schemes are designed for systems assuming a source and several receivers with one target receiver among them which is denoted as destination. In addition, the source or the receivers are not restricted to be static. These schemes follow a request-answer strategy,...
Multiuser multiple-input multiple-output (MU-MIMO) transmission technique based on orthogonal frequency division multiplexing (OFDM) system has been received great deal of attention in recent years due to its potential higher spectral efficiency. However, because of the accuracy of channel state information, co- scheduled mobile users may suffer large residual multiuser interference in MU-MIMO system...
In this work we propose an iterative decision feedback with constellation constraints receiver for cloud radio access networks that considers the quantization effect in the fronthaul. The proposed constellation constrained device introduces a number of selected points as candidates for decision feedback interference cancellation. By introducing a reliability checking, a higher degree of freedom is...
Cooperative Beamforming is a flourishing technique to resolve many issues related to Cognitive Radio Networks. One of them is to overcome the problems caused by failure of several nodes in a network. In case of node failures, the optional paths are selected instead of intended paths which may cause additional delay. This work suggests a route conservation protocol with minimal changes in a basic routing...
When an autonomous guided vehicle (AGV) rotates its direction in a narrow indoor environment, overlapped zone or dead zone may happen depending on either sensing multiple landmarks or no sensing landmark. We present a self-localization of an AGV based on artificial beacons. With this approach, the position of an AGV is determined by its relative distance to a beacon, whose location is known in advance...
IEEE 802.11-based wireless LAN, commonly referred to as Wi-Fi, has become a universal solution for the last-hop network access. In large and public assembly places, people may use their mobile devices to view the video of the same popular events via the same wireless access points (APs). However, current 802.11 APs transmit the same video stream multiple times via separate unicast sessions due to...
This paper presents the new radio network technology and applications capability for the “LoRa” systems, which ensure long range data transfer, very high number of local subscribers and low power consume. Although this standard provides low data rates, it is intended to be a solution for sensor networks, that don't need too much information to be transmitted at a specific time. The expectation is...
Wireless embedded systems are becoming an increasingly important part of our lives. Information from such systems is almost exclusively meaningful when it is coupled with location information, or the location information itself is the desired knowledge to obtain. In this paper we explore a special sub-problem of location discovery: determining relative node positions when the nodes to be discovered...
Wireless technologies such as WiFi and Bluetooth are widely used for mobile data communications. However, these technologies are affected by interference resulting from shared access to unlicensed frequency bands. Visible light communication is an alternative means for data exchange over an optical channel. It has several advantages over currently used radio-based technologies, including a full-duplex...
The ubiquitous adoption of portable smart devices has enabled a new way of communication via Pocket Switched Networks (PSN), whereby messages are routed by personal devices inside the pockets of ever-moving people. PSNs provide opportunities for various interesting applications such as location based social networking, geolocal advertising, and military missionsin active battlefields where the central...
Multicasting, which is a one-to-many communication, is motivated by the increasing importance of real-time and multimedia applications with different QoS requirements. This paper presented a non-uniform distributed hash function for wireless ad hoc networks. This function allocates a unique interval to the receiver nodes based on the path weight and the random speed of nodes. This allocation leads...
For IoT applications that require near real-time wireless connections, the traditional TCP protocol is not adept enough due to the size of its packet header, its conservative Additive Increase Multiplicative Decrease (AIMD) congestion control algorithm and its slow start strategy. This paper mainly evaluates three kinds of reliable UDP-based transport protocols namely, RUBDP, UDT, and PA-UDP, for...
In this work, reliable and secure transmission over generic-Gaussian wiretap channel model is investigated. An Adaptive Granular Hybrid Automatic Repeat reQuest (AG-HARQ) protocol is proposed which tries to minimize the required rate for successful decoding by the legitimate parties while amplifying the privacy by minimizing the information leakage to a wiretapper. In the case of LDPC decoding failure...
In this paper, we study secure transmission designs for underlay cognitive radio networks in the present of randomly distributed eavesdroppers. We consider the scenario where a secondary transmitter sends confidential messages to a secondary receiver subject to an interference constraint set by the primary user. We design two transmission protocols under different channel knowledge assumptions at...
This paper investigates the power control problem for broadcast vehicular communications in the presence of adjacent carrier interference (ACI). First, we study the impact of ACI on vehicle-to-vehicle (V2V) communications and conclude that the ACI indeed significantly affects the reliability of V2V links. Second, we formulate a power control optimization problem for vehicles to reduce the negative...
We propose a multi-hop reliable broadcasting (M-HRB) scheme suitable for a wide range of vehicular ad-hoc network (VANET) applications in urban setting. Multi-hop reliability is performed using local state information. Basically, a street is divided into multiple cells to form grid-like zones. We apply a proactive local state processing scheme exploiting features of periodic beacons to estimate wireless...
It is expected that the use of cognitive radio for smart grid communication will be indispensable in near future. Recently, RPL for cognitive radio enabled Advanced Metering Infrastructure (AMI) networks is attractive. Our objective in this paper is to propose an enhance RPL to improve efficiency and reliability of cognitive radio enabled AMI networks. Our protocol is receiver-based in nature, which...
In this paper, existing results regarding the fundamental limits of simultaneous energy and information transmission in wireless networks are reviewed. In point-to-point channels, the fundamental limits on the information rate given a minimum energy rate constraint are fully characterized by the notion of information-energy capacity function introduced by Varshney in 2008. In a centralized multi-user...
Modern digital communication systems can benefit from soft-decision algorithms in receiver implementations. Such algorithms require reliability information about every data bit which is typically given in terms of Log-Likelihood Ratios (LLRs) or short L-Values. Several efficient receiver implementations based on L-Values have already been proposed in the literature. Many of them exploit the famous...
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