Dilution of Position Calculation for Accuracy Improvement in Wireless Location Systems

2011 ◽  
Vol 204-210 ◽  
pp. 1036-1040
Author(s):  
Yung Chuan Lin ◽  
Chien Sheng Chen ◽  
He Nian Shou ◽  
Chi Tien Sun
Keyword(s):  
Communication Systems ◽  
Selection Criterion ◽  
Matrix Inversion ◽  
Base Stations ◽  
Inversion Method ◽  
Wireless Location ◽  
The Matrix ◽  
Measurement Units ◽  
Geometric Dilution Of Precision ◽  
Volume Method

Geometric dilution of precision (GDOP) represents the geometric effect on the relationship between measurement error and positioning determination error. In the calculation of GDOP value, the maximum volume method does not guarantee the optimal selection of the four measurement units. The conventional method for calculating GDOP is to use matrix inversion to all subsets. In this paper, we employ GDOP using the matrix inversion method to select appropriate base stations (BSs) in cellular communication systems. The proposed BS selection criterion performs better than the random subsets of four or five BSs chosen from all seven BSs. The performances of MS location strongly depend on the relative position of the MS and BSs. Therefore, it is very important to select a subset with the most appropriate BSs rapidly and reasonably before positioning.

scholarly journals Calculation of Weighted Geometric Dilution of Precision

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Chien-Sheng Chen ◽  
Yi-Jen Chiu ◽  
Chin-Tan Lee ◽  
Jium-Ming Lin
Keyword(s):  
Communication Systems ◽  
Approximation Error ◽  
Matrix Inversion ◽  
Location Estimation ◽  
Inversion Method ◽  
Error Statistics ◽  
Positioning Systems ◽  
Dilution Of Precision ◽  
Measurement Units ◽  
Geometric Dilution Of Precision

To achieve high accuracy in wireless positioning systems, both accurate measurements and good geometric relationship between the mobile device and the measurement units are required. Geometric dilution of precision (GDOP) is widely used as a criterion for selecting measurement units, since it represents the geometric effect on the relationship between measurement error and positioning determination error. In the calculation of GDOP value, the maximum volume method does not necessarily guarantee the selection of the optimal four measurement units with minimum GDOP. The conventional matrix inversion method for GDOP calculation demands a large amount of operation and causes high power consumption. To select the subset of the most appropriate location measurement units which give the minimum positioning error, we need to consider not only the GDOP effect but also the error statistics property. In this paper, we employ the weighted GDOP (WGDOP), instead of GDOP, to select measurement units so as to improve the accuracy of location. The handheld global positioning system (GPS) devices and mobile phones with GPS chips can merely provide limited calculation ability and power capacity. Therefore, it is very imperative to obtain WGDOP accurately and efficiently. This paper proposed two formations of WGDOP with less computation when four measurements are available for location purposes. The proposed formulae can reduce the computational complexity required for computing the matrix inversion. The simpler WGDOP formulae for both the 2D and the 3D location estimation, without inverting a matrix, can be applied not only to GPS but also to wireless sensor networks (WSN) and cellular communication systems. Furthermore, the proposed formulae are able to provide precise solution of WGDOP calculation without incurring any approximation error.

A Matrix-Inversion Method for Gamma-Source Mapping From Gamma-Count Data

2013 ◽  
Author(s):  
Ian Adsley ◽  
Richard K. Bull ◽  
Claire Burgess
Keyword(s):  
Matrix Inversion ◽  
Source Distribution ◽  
Inversion Method ◽  
Practical Applications ◽  
Highly Active ◽  
Co60 Source ◽  
The Matrix ◽  
Simple Matrix ◽  
Inversion Procedure ◽  
Matrix Inversion Method

In a previous paper (1) it was proposed that a simple matrix inversion method could be used to extract source distributions from gamma-count maps, using simple models to calculate the response matrix. The method was tested using numerically generated count maps. In the present work a 100 kBq Co60 source has been placed on a gridded surface and the count rate measured using a NaI scintillation detector. The resulting map of gamma counts was used as input to the matrix inversion procedure and the source position recovered. A multisource array was simulated by superposition of several single-source count maps and the source distribution was again recovered using matrix inversion. The measurements were performed for several detector heights. The effects of uncertainties in source-detector distances on the matrix-inversion method are also examined. The results from this work give confidence in the application of the method to practical applications, such as the segregation of highly active objects amongst fuel-element debris.

Study of a Computational-Time-Saving Scheme for Quantitative Leed Analysis by the Matrix Inversion Method

2003 ◽  
Vol 10 (02n03) ◽  
pp. 493-497 ◽  
Author(s):  
Y. Y. Sun ◽  
A. T. S. Wee ◽  
A. C. H. Huan
Keyword(s):  
Matrix Inversion ◽  
Critical Parameters ◽  
Computational Time ◽  
Inversion Method ◽  
Slab Thickness ◽  
Time Saving ◽  
Structure Search ◽  
The Matrix ◽  
Matrix Inversion Method ◽  
Energy Dependent

A computational-time-saving scheme for quantitative LEED analysis by the matrix inversion method was studied. Two computational-time-critical parameters, the number of atomic layers (Nl) in the surface slab and the number of ion-core scattering phase shifts (l max ), were tested for energy dependence. Our study on a Cu(210) surface shows that no dependence of Nl on the incident energy exists in the energy range of LEED (50–400 eV), i.e. using energy-dependent Nl is not feasible. The effect of slab thickness reduction on the precision of the Pendry R-factor based best-fit structure search was then studied. This study provides a guide to the selection of surface slab thickness in quantitative LEED analysis by the matrix inversion method. Also, we show that using an energy-dependent l max can save nearly half of the overall computational time for obtaining a set of I–V curves by the matrix inversion method.

scholarly journals Hybrid TOA/AOA Approximate Maximum Likelihood Mobile Localization

2010 ◽  
Vol 2010 ◽  
pp. 1-5 ◽  
Author(s):  
Mohamed Zhaounia ◽  
Mohamed Adnan Landolsi ◽  
Ridha Bouallegue
Keyword(s):  
Maximum Likelihood ◽  
Communication Systems ◽  
Base Stations ◽  
Time Of Arrival ◽  
Angle Of Arrival ◽  
Arrival Angle ◽  
Wireless Location ◽  
Approximate Maximum Likelihood ◽  
Mobile Localization ◽  
Location Algorithm

This letter deals with a hybrid time-of-arrival/angle-of-arrival (TOA/AOA) approximate maximum likelihood (AML) wireless location algorithm. Thanks to the use of both TOA/AOA measurements, the proposed technique can rely on two base stations (BS) only and achieves better performance compared to the original approximate maximum likelihood (AML) method. The use of two BSs is an important advantage in wireless cellular communication systems because it avoids hearability problems and reduces network signaling burden. Simulation results show that, for certain scenarios, the proposed hybrid TOA/AOA AML with two BSs can outperform the AML with up to six BSs.

scholarly journals Interference Cancellation Based Spectrum Sharing for Massive MIMO Communication Systems

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3584
Author(s):  
Milembolo Miantezila Junior ◽  
Bin Guo ◽  
Chenjie Zhang ◽  
Xuemei Bai
Keyword(s):  
Interference Cancellation ◽  
Communication Systems ◽  
Spectrum Sharing ◽  
Null Space ◽  
Base Station ◽  
Base Stations ◽  
Small Cells ◽  
Data Traffic ◽  
New Approach ◽  
Lte Advanced

Cellular network operators are predicting an increase in space of more than 200 percent to carry the move and tremendous increase of total users in data traffic. The growing of investments in infrastructure such as a large number of small cells, particularly the technologies such as LTE-Advanced and 6G Technology, can assist in mitigating this challenge moderately. In this paper, we suggest a projection study in spectrum sharing of radar multi-input and multi-output, and mobile LTE multi-input multi-output communication systems near m base stations (BS). The radar multi-input multi-output and mobile LTE communication systems split different interference channels. The new approach based on radar projection signal detection has been proposed for free interference disturbance channel with radar multi-input multi-output and mobile LTE multi-input multi-output by using a new proposed interference cancellation algorithm. We chose the channel of interference with the best free channel, and the detected signal of radar was projected to null space. The goal is to remove all interferences from the radar multi-input multi-output and to cancel any disturbance sources from a chosen mobile Communication Base Station. The experimental results showed that the new approach performs very well and can optimize Spectrum Access.

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