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Accurate channel estimation is essential for time domain synchronous OFDM (TDS-OFDM), which is a key enabling technology in digital terrestrial multimedia broadcasting (DTMB) standard. However, conventional channel estimation schemes for TDS-OFDM systems suffer from the obvious performance loss in high-speed scenarios. In this paper, by exploiting the temporal correlation of wireless channels, we...
Cross-technology interference on the license-free ISM bands has a major negative effect on the performance of Wireless Sensor Networks (WSNs). Channel hopping has been adopted in the Time-Slotted Channel Hopping (TSCH) mode of IEEE 802.15.4e to eliminate blocking of wireless links caused by external interference on some frequency channels. This paper proposes an Enhanced version of the TSCH protocol...
This paper proposes an efficient channel parameters estimation design for Single Carrier Frequency Domain Equalization (SC-FDE) in High Frequency (HF) wireless communications. This design is implemented to improve the performance of existing channel estimation by integrating and optimizing traditional channel statistical characteristics estimation. Based on the Synchronization Training Sequences (STS)...
Due to the difficult characterization of the propagation model, most studies on racking of mobile nodes assume the correct knowledge of the power-distance gradients or the path-loss exponents (PLEs). In this paper, we first investigate the impact of erroneous PLEs on positioning of a wireless nodes when both distance and bearing measurements are available. Thus, an analytical expression of the mean...
Mobile networks and user equipments continuously evolve to circumvent the data traffic growth and the increasing number of users. However, the complexity and heterogeneity of such systems (3G, LTE, LTE-A, etc.) makes power one of the most critical metric. In this context, power estimation has become an unavoidable task in the design process. In this paper, a dynamic power estimation methodology for...
Localization and asset tracking are key components of the Internet of Things or the fourth industrial revolution called “Industry 4.0”. Current systems using GPS signals cannot be used indoors. Alternative systems for indoor localization exist, but they cannot be battery power with tiny batteries over multiple years. To overcome these drawbacks we propose a new localization concept based on an ultra-low-power...
The most important function of a sensor network is to collect information from the environment. For many applications, it is important that the location or sensor that originates the collected information is ascertained. This article presents the detection of a mobile sensor's location in an indoor environment with the help of known location sensors (anchors) placed in the environment. Anchor sensors...
In this paper we present a simulation tool to determine the characterization of a Vehicle-to-Infrastructure radio channel at 60GHz in two scenarios: suburban and urban. A precise estimation considering the topology and the morphology of both areas is performed with the aid of in-house deterministic 3D ray launching algorithm. Estimations of received power as well as of delay parameters show the relevance...
In this work, the analysis on the design and implementation of dense wireless sensor networks is presented, by performing deterministic wireless channel analysis, providing assessment on topological and morphological impact of complex urban environments in the operation of the employed wireless sensor networks, within WLAN/WPAN standards. The proposed methodology, combining initial radioplanning estimations...
Railway transportation systems are gaining relevance in their adoption, driven by decreasing costs, higher interconnectivity options and timely operation. The Railway Transportation system is comprised by vehicular elements, as well as several infrastructure elements, which require constant interaction and communication, for tele-control and tele-command, signaling systems, passenger information and...
A sparse channel estimation method is proposed for cyclic prefixed single carrier block transmission with frequency domain equalization (CP-SCBT-FDE) system employed in sparse frequency selective fading channels by using compressed sensing (CS) technique. The sparse channel estimation in CP-SCBT-FDE system is formulated as a canonical CS problem, and a measurement matrix that satisfies restricted...
Demand on multimedia content by consumers' handheld devices over wireless channels is on the increase. In view of the accelerated trend towards consumption of high quality video, power utilization by mobile devices is expected to excessively increase. This paper presents a power and bandwidth efficient resource allocation scheme considering the end user's Quality of Experience (QoE) in the context...
When mobile devices use the distance between devices in an application, the distance should be measured easily and accurately. The RSSI system can be used to estimate the distance easily and inexpensively because most devices can estimate the received signal strength. However, estimating the distance using a RSSI is difficult due to inaccuracies. Therefore, we propose distance awareness algorithm...
This paper introduces the coarse time-of-arrival (ToA) estimation in wireless sensor networks (WSN) via orthogonal frequency division multiple access (OFDMA). In the proposed technique, each sensor node exploits a set of orthogonal subcarrier as its allocated signature to respond of the ToA estimation requests transmitted by target nodes. The target node utilizes the orthogonality across sub-carriers...
Recently, 60 GHz technology has become a promising alternative for indoor positioning systems because it can provide very accurate temporal and spatial information for precise time of arrival (TOA) estimation. However, non-line-of-sight (NLOS) propagation in indoor environments can significantly degrade the localization accuracy with 60 GHz signals. To reduce the effects of NLOS propagation, a fingerprinting...
A 60 GHz ranging model is established and a strongest path search ranging algorithm based on beamforming is proposed. The range error caused by a non-line of sight (NLOS) channel is mitigated by modeling the corresponding delay bias. Outlier detection is employed to improve the accuracy. Performance results are presented which show that 60 GHz ranging can achieve centimeter level accuracy in indoor...
A target can be positioned by wireless communication sensors. In practical system, the range based sensors may have biased measurements. The biases are mostly constant value, but they may jump abruptly in some special scenarios. An on-line bias change detection and estimation algorithm is presented in this paper. This algorithm can detect the jump bias based on Chi-Square Test, and then estimate the...
Industrial wireless sensor networks (IWSNs) have become popular, given the lower cost of installation than wired networks and their flexibility. WSNs are applied in monitoring, measurement, and control. Nuclear power plants (NPPs), in particular, have not been eager to adopt WSNs due to reliability, electromagnetic and radio frequency interference (EMI/RFI) as well as security concerns. On the other...
The purpose of this paper is to evaluate the impact of the node speed on the ranging estimation for location applications with Wireless Body Area Networks (WBAN). While estimated with the 3-Way ranging protocol (3-WR), this distance between two nodes placed on the body can be affected by the human movements. Thus, we study theoretically the ranging error with the 3-WR, based on a perfect channel,...
In this paper, a new approach for sampling rate offset (SRO) estimation between nodes of a wireless acoustic sensor network (WASN) is proposed using the phase drift of the coherence function between the signals. This method, referred to as least squares coherence drift (LCD) estimation, assumes that the SRO induces a linearly increasing phase-shift in the short-time Fourier transform (STFT) domain...
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