1,721,008 research outputs found
MIMO Positioning for IMT-Advanced Systems Based on Geometry Approach in NLOS Environments
Full text linkIn wireless communications, one of the main problems that deteriorate the accuracy of location and positioning (L&P) estimation is non line of sight (NLOS) propagation. With the advances of multiple input multiple output (MIMO) technology as one of the features of International Mobile Telecommunications-Advanced (IMT-Advanced) systems, it has become feasible to adopt the technology into the mobile location scenario. By exploiting the multipath characteristics of the MIMO system, it is possible to estimate the position of mobile stations (MS) by considering the capability of MIMO to mitigate the effects of non line of sight (NLOS) conditions. In this paper we developed geometric approach by utilizing the advantages of MIMO system and employ the time of arrival (TOA) as range measurements for improving location estimation in various NLOS environments. The performance of the proposed method has been evaluated through computer simulation. The results of our simulation demonstrate the advantages of the proposed algorithm in comparison with the conventional LLS algorithm meeting the Federal Communications Commission (FCC) requirements
Utilising MIMO for Location and Positioning in IMT -Advanced Systems
Full text linkWith the advances of multiple input multiple output (MIMO) technology as one of IMT-Advanced features, it has hecome feasible to adopt the technology into the mobile location
scenario. By exploiting the multipath characteristics of the
MIMO system, it is possible to estimate the position of mobile stations (MS) by considering the capability of MIMO to mitigate the non line of sight (NLOS) conditions that deteriorate the accuracy of location estimation. In this paper we developed geometric approach by utilizing the advantages of MIMO system and employ the time of arrival (TOA) as range measurements for improving location estimation. The performance of the proposed method has been evaluated through computer simulation. The results of our simulation demonstrate that the proposed algorithm is significantly more effective in location accuracy than the conventional technique (LLS algorithm) and MIMO antenna configurations can achieve high accuracy for location estimation which meets the Federal Communications Commission (FCC) requirements
MIMO Positioning for IMT-Advanced Systems based on Geormetry Approach in NLOS
No full textAn enhanced positioning technique which utilities MIMO characteristics of PHY layer in IMT-advanced systems (both WiMAX and LTE) is proposed and investigated. Advantages of the proposed technique are demonstrated through computer simulations of the most typical operation scenarios
A Broadband P-Shaped Circularly Polarized Monopole Antenna With A Single Parasitic Strip
No full textA new broadband circular polarization (CP) monopole antenna with simple structure is proposed. The antenna consists of a P-shaped monopole and modified ground plane with rectangular stub, and results demonstrated that the 10 dB impedance bandwidth (ZBW) is 118.5% (1.6–6.25 GHz) and the 3 dB axial-ratio bandwidth (ARBW) is 104.4% (1.9–6.05 GHz). Procedures to improve the proposed antenna design and the CP mechanism analysis were performed. The performance of different parameters is presented. The advantages of the proposed antenna are broader ZBW and ARBW, simpler structure, and compact size
Eye closure and open detection using Adaptive Thresholding Histogram Enhancement (ATHE) technique and connected components utilisation
Full text linkEye closure detection is an important operation prior to carry out the main algorithm such as iris recognition algorithms, and eye tracking algorithms. This paper introduces a method to detect eye closure using Adaptive Thresholding Histogram Enhancement (ATHE) technique and connected component utilisation. The ATHE technique is a combination of histogram enhancement and estimation threshold technique. Firstly, in this proposed method the eye region is required to be localised. The ATHE technique enhances the eye region image then and yield the threshold value to segment the iris region. Based on the segmentation result, the connected components of binary image are used to classify the state of eye whether open or close. This classification is based on the shape and size of segmented region. The performance of the proposed technique is tested and validated by using UBIRIS, MMU and CASIA iris image database
New Broadband L-Shaped CPW-Fed Circularly Polarized Monopole Antenna With Asymmetric Modified Ground Plane And A Couple Series-Aligning Inverted L-Shaped Strip
No full textA new compact coplanar waveguide (CPW) -fed broadband circularly polarized (CP) monopole antenna is proposed in this study. The antenna structure is composed of an L-shaped monopole, an asymmetric
modified ground plane and a couple series-aligning inverted L-shaped strip. The modification of cutting two slots in the asymmetric ground plane achieves a wide CP bandwidth, and a couple series-aligning inverted L-shaped strip is introduced with the left ground plane to achieve broadband impedance bandwidth (IBW). A - 10 dB IBW of 103% (2–6.2 GHz) and 3 dB axial ratio bandwidth (ARBW) of 98% (1.9– 5.85 GHz) is achieved. The antenna design process and the parametric study are presented, and the CP mechanism is analyzed
Wireless Location Positioning Based on WiMAX Features - A Preliminary Study
No full textIn this paper, we exploit the potential of positioning technologies in wireless broadband communications, which are based on worldwide interoperability for microwave access (WiMAX), in particular the IEEE802.16* standards. By utilizing the additional features in WiMAX including multiple input multiple output (MIMO), adaptive modulation and coding (AMC), beamforming, relay station and power control, we believe that the features can be used for enhancing the location estimation accuracy in location services
High-performance, fault-tolerant architecture for reliable hybrid nanolectronic memories
Full text linkAlthough hybrid nanoelectronic memories (hybrid memories) promise scalability potentials such as ultrascale density and low power consumption, they are expected to suffer from high defect/fault density reducing their reliability. Such defects/faults can impact any part of the memory system including the memory cell array, the encoder and the decoder. This article presents a high-performance, fault-tolerant architecture for hybrid memories; it is based on a combination of two techniques: (i) an error correction scheme that tolerates both random and clustered faults in memory cell array and (ii) an on-line masking incorporated into the decoder to tolerate faults in the decoder. Moreover, the decoding process is optimized for area and performance by reversing the decoding sequence. Experimental results show that the proposed architecture realizes a higher performance and competitive reliability level at a comparable overhead as compared with the state-of-the-art. For example, the architecture decodes 5× faster and provides 0.7% better reliability (assuming 10% fault rate) at the cost of similar area overhead (for 1024-bit memory word) as compared to Reed-Solomon code
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