Inertial Measurement Unit based Virtual Antenna Arrays - DoA Estimation and Positioning in Wireless Networks

Today we have different location based services available in a mobile phone or mobile station (MS). These services include: direction finding to nearby ATMs, locating favorite food restaurants, or finding any target destination. Similarly, we see different applications of the positioning and navigation systems in firefighting or other rescue operations. The common factor in almost all of the location based services is the system's ability to determine the user's current position, with reference to a floor plan or a navigation map. Current technologies are using sensor data measurements from one or more sensors, available to the positioning device, for positioning and navigation. Typical examples are radio based positioning such as global positioning system, inertial sensors based inertial navigation system, or camera based positioning systems. Different accuracy and availability conditions of the positioning and navigation solution can be obtained depending on the positioning algorithms and the available sensor information.Nowadays, the focus of research in positioning and navigation has been mostly on the use of existing hardware infrastructure and low-cost solutions, such that the proposed technique can be deployed with ease and without extra infrastructure requirements as well as without any expensive sensor equipment. In this work, we investigate a novel idea for positioning using existing wireless networks and low-cost inertial sensor measurements available at the MS. We propose to use received baseband radio signal along with inertial sensor data, such as accelerometer and rate gyroscope measurements, for direction of arrival (DoA) estimation and positioning. The DoA information from different base stations or access points can be used to estimate the MS position using triangulation technique. Furthermore, due to size and cost restrictions it is difficult to have real antenna arrays at the MS, the idea of DoA estimation and positioning is proposed to be used with single antenna devices by using the so-called virtual antenna arrays.We have presented our research results in three different papers. We provide measurement based results to perform a quantitative evaluation of DoA estimation using arbitrary virtual antenna arrays in 3-D; where a state-of-the-art high-resolution algorithm has been used for radio signal parameter estimation. Furthermore, we provide an extended Kalman filter framework to investigate the performance of unaided inertial navigation systems with 3-axis accelerometer and 3-axis rate gyroscope measurements, from a six-degrees-of-freedom inertial measurement unit. Using the extended Kalman filter framework, we provide results for position estimation error standard deviation with respect to integration time for an unaided inertial navigation system; where the effect of different stochastic errors noise sources in the inertial sensors measurements such as white Gaussian noise and bias instability noise is investigated. Also, we derive a closed form expression for Cramér-Rao lower bound to investigate DoA estimation accuracy for a far-field source using random antenna arrays in 3-D. The Cramér-Rao lower bound is obtained using known antenna coordinates as well as using estimated antenna coordinates, where the antenna coordinates are estimated with an uncertainty whose standard deviation is known. Furthermore, using Monte-Carlo simulations for random antenna arrays, we provide Cramér-Rao lower bound based performance evaluation of random 3-D antenna arrays for DoA estimation

Source Localization Using Virtual Antenna Arrays

Using antenna arrays for direction of arrival (DoA) estimation and source localization is a well-researched topic. In this paper, we analyze virtual antenna arrays for DoA estimation where the antenna array geometry is acquired using data from a low-cost inertial measurement unit (IMU). Performance evaluation of an unaided inertial navigation system with respect to individual IMU sensor noise parameters is provided using a state space based extended Kalman filter. Secondly, using Monte Carlo simulations, DoA estimation performance of random 3-D antenna arrays is evaluated by computing Cramér-Rao lower bound values for a single plane wave source located in the far field of the array. Results in the paper suggest that larger antenna arrays can provide significant gain in DoA estimation accuracy, but, noise in the rate gyroscope measurements proves to be a limiting factor when making virtual antenna arrays for DoA estimation and source localization using single antenna devices

Significant Analysis for Financial Statements: An Empirical Study of National and Unilever Foods

Choosing vital, reliable and hustle free analysis is a bit difficult situation for most of the financiers and managers as there are so many analyses. This study focuses on most significant analyses to perform on financial statements. To accomplish this study, financial statements of two companies, Unilever foods and National foods has selected to perform analysis. Results show that vertical analysis can be a suspicious analysis as it total assets and sales fluctuate gradually. Horizontal analysis is somehow better analysis than vertical analysis as it shows negative or positive trend of variables. DuPont analysis is a reliable analysis but it taken into consideration only two years. However, ratio analysis is seems to be best analysis as it gives concise and paramount review of firm’s performance. According to these analyses, Unilever Foods is better corporate than National Foods. Further results are discussed in the light of these analyses. Keywords: Vertical analysis, Horizontal analysis, DuPont analysis, Ratio analysi

Antioxidant activity and hepatoprotective effect of Cichorium intybus (Kasni) seed extract against carbon tetrachloride-induced liver toxicity in rats

Purpose: To assess the antioxidant and hepatoprotective activity of the aqueous-methanol extract of Cichorium intybus seeds (C. intybus) against carbon tetrachloride (CCl4)-induced liver toxicity in albino Wistar rats.Method: The seed extract of C. intybus was prepared in aqueous methanol (20:80) via Soxhlet solvent extraction process. CCl4 (0.8 mL/kg) was administered to induce hepatic damage in Wistar rats. The seed extract (100, 250 and 500 mg/kg doses) and a 25 mg/kg dose of silymarin (as standard drug) were administered orally to separate groups of albino Wistar rats for 14 days. Blood samples from the rats were analyzed for biochemical markers for hepatic injury. The tissue samples of the rats were subjected to histopathological studies as well as analyzed for liver antioxidants.Results: The results for biochemical markers revealed that the rats treated with the extract (500 mg/kg dose) showed a maximum elevation of catalase (48.90 μmole of H2O2 consumed/min/mg protein), glutothione peroxidase (22.1 mg GSH consumed/min/mg protein), superoxide dismutase (14.2 units/min/mg protein), and a reduction in glutathione (18.1 μmole of GSH/mg protein). Serum biochemical parameters including serum glutamate oxaloacetate transaminase (SGOT), serum glutamate pyruvate transaminase (SGPT), alkaline phosphate (ALKP), and direct bilirubin were significantly (p < 0.01) increased in the treated groups. Oral administration of different doses of C. intybus seed extract significantly (p < 0.01) protected the hepatic cells from impairment. The biochemical markers and hematological parameters were also normal in extract-treated rats in contrast to the standard (silymarin) and control groups.Conclusion: The results show that C. intybus plant is potential a good natural source of natural hepatoprotective and antioxidants agents.Keywords: Cichorium intybus, Antioxidant, Hepatoprotective Biomarkers, Silymarin, Hematological parameter

An Unbiased Lipid Phenotyping Approach To Study the Genetic Determinants of Lipids and Their Association with Coronary Heart Disease Risk Factors.

Direct infusion high-resolution mass spectrometry (DIHRMS) is a novel, high-throughput approach to rapidly and accurately profile hundreds of lipids in human serum without prior chromatography, facilitating in-depth lipid phenotyping for large epidemiological studies to reveal the detailed associations of individual lipids with coronary heart disease (CHD) risk factors. Intact lipid profiling by DIHRMS was performed on 5662 serum samples from healthy participants in the Pakistan Risk of Myocardial Infarction Study (PROMIS). We developed a novel semi-targeted peak-picking algorithm to detect mass-to-charge ratios in positive and negative ionization modes. We analyzed lipid partial correlations, assessed the association of lipid principal components with established CHD risk factors and genetic variants, and examined differences between lipids for a common genetic polymorphism. The DIHRMS method provided information on 360 lipids (including fatty acyls, glycerolipids, glycerophospholipids, sphingolipids, and sterol lipids), with a median coefficient of variation of 11.6% (range: 5.4-51.9). The lipids were highly correlated and exhibited a range of associations with clinical chemistry biomarkers and lifestyle factors. This platform can provide many novel insights into the effects of physiology and lifestyle on lipid metabolism, genetic determinants of lipids, and the relationship between individual lipids and CHD risk factors

Human knockouts and phenotypic analysis in a cohort with a high rate of consanguinity

A major goal of biomedicine is to understand the function of every gene in the human genome. Loss-of-function mutations can disrupt both copies of a given gene in humans and phenotypic analysis of such 'human knockouts' can provide insight into gene function. Consanguineous unions are more likely to result in offspring carrying homozygous loss-of-function mutations. In Pakistan, consanguinity rates are notably high. Here we sequence the protein-coding regions of 10,503 adult participants in the Pakistan Risk of Myocardial Infarction Study (PROMIS), designed to understand the determinants of cardiometabolic diseases in individuals from South Asia. We identified individuals carrying homozygous predicted loss-of-function (pLoF) mutations, and performed phenotypic analysis involving more than 200 biochemical and disease traits. We enumerated 49,138 rare (<1% minor allele frequency) pLoF mutations. These pLoF mutations are estimated to knock out 1,317 genes, each in at least one participant. Homozygosity for pLoF mutations at PLA2G7 was associated with absent enzymatic activity of soluble lipoprotein-associated phospholipase A2; at CYP2F1, with higher plasma interleukin-8 concentrations; at TREH, with lower concentrations of apoB-containing lipoprotein subfractions; at either A3GALT2 or NRG4, with markedly reduced plasma insulin C-peptide concentrations; and at SLC9A3R1, with mediators of calcium and phosphate signalling. Heterozygous deficiency of APOC3 has been shown to protect against coronary heart disease; we identified APOC3 homozygous pLoF carriers in our cohort. We recruited these human knockouts and challenged them with an oral fat load. Compared with family members lacking the mutation, individuals with APOC3 knocked out displayed marked blunting of the usual post-prandial rise in plasma triglycerides. Overall, these observations provide a roadmap for a 'human knockout project', a systematic effort to understand the phenotypic consequences of complete disruption of genes in humans.D.S. is supported by grants from the National Institutes of Health, the Fogarty International, the Wellcome Trust, the British Heart Foundation, and Pfizer. P.N. is supported by the John S. LaDue Memorial Fellowship in Cardiology from Harvard Medical School. H.-H.W. is supported by a grant from the Samsung Medical Center, Korea (SMO116163). S.K. is supported by the Ofer and Shelly Nemirovsky MGH Research Scholar Award and by grants from the National Institutes of Health (R01HL107816), the Donovan Family Foundation, and Fondation Leducq. Exome sequencing was supported by a grant from the NHGRI (5U54HG003067-11) to S.G. and E.S.L. D.G.M. is supported by a grant from the National Institutes of Health (R01GM104371). J.D. holds a British Heart Foundation Chair, European Research Council Senior Investigator Award, and NIHR Senior Investigator Award. The Cardiovascular Epidemiology Unit at the University of Cambridge, which supported the field work and genotyping of PROMIS, is funded by the UK Medical Research Council, British Heart Foundation, and NIHR Cambridge Biomedical Research Centre ... Fieldwork in the PROMIS study has been supported through funds available to investigators at the Center for Non-Communicable Diseases, Pakistan and the University of Cambridge, UK

Comparison of Frequency Domain Equalizers to Time Domain Equalizers in WCDMA

Future mobile platforms will contain an increased amount of wireless technologies. As technologies mature it will be necessary to find synergies between them. This could be in the form of reusing hardware blocks and algorithms. By using Fast Fourier Transforms (FFT/IFFT) and performing channel cancellation/equalization in frequency domain for wideband code division multiple access (WCDMA) will provide us a platform which can support LTE and WiFi together with WCDMA. In this thesis, an equalizer based on Fast Fourier Transforming (FFT) the input signal, cancelling the propagation channel in frequency domain, and finally reverting to time domain using an IFFT would be devised for WCDMA. The performance of frequency domain equalizer is then compared with traditional time domain equalizer based on G-RAKE method for different performance metrics. To evaluate and compare the performance of frequency domain equalizer (FFT) with time domain equalizer (G-RAKE), a simulator is made in IT++. Several simulations are performed and the obtained results are analyzed in Matlab. Firstly, for channel estimation at the receiver, common pilot channel (CPICH) is used and multiple channel estimates are obtained to get a filtered channel estimate. Along-with CPICH pilot symbols, data symbols of a desired user and four other user‟s data symbols are transmitted from the base-station (Node B). Using QPSK signaling, un-coded bit-error-rate (BER) results of the desired data user are compared for the two equalization methods. Simulation results are obtained for single path and multi-path propagation channels with different delay spread values. Included in the modeling are one receive and transmit antenna, other cell interference, i.e., non-white noise, frequency errors at mobile station (UE), and analog-to-digital (A/D) quantization

Tightly Coupled Positioning and Multipath Radio Channel Tracking

Radio based localization is an active research topic with a wide range of applications. In this paper, we focus on localization of a radio receiver equipped with an inertial measurement unit. The localization is performed while simultaneously constructing a map of the small scale fading pattern in the local radio environment. The map in our case is a ray-trace-based multipath channel model. This solution is enabled by sensor fusion of information from the channel estimation data and the inertial sensors, and it does not assume any knowledge of, e.g., transmitter locations. The sensor data is fused in a recursive state space model that combines the kinematic motion model with the ray-based radio channel model, and the state vector is estimated using a particle filter. The choice of the particle filter is justified by the multimodal characteristics of the posterior likelihood distributions that follows from the nonlinearities of the problem. The work is assuming a single receiver antenna but the approach can also be transferred to multiple antenna systems. We study the performance of the approach under realistic assumptions, based on the performance of today’s low-cost inertial sensors and radio systems, including accelerometer and gyroscope noise, and also radio receiver frequency error and noise. Simulations show a significant improvement in long-term positioning performance, evaluated against dead reckoning. The work is concluded with experiments which serve as a proof of concept for the proposed technique, using no extra equipment compared to what can be found in a modern cellular phone

Direction of Arrival Estimation with Arbitrary Virtual Antenna Arrays using Low Cost Inertial Measurement Units

In this paper, we have investigated the use of virtual antenna arrays at the receiver to do single antenna direction-of-arrival estimation. The array coordinates are obtained by doing simple dead reckoning using acceleration and angular speed measurements from a low cost micro-electro-mechanical system inertial measurement unit (IMU). The proposed solution requires no extra hardware in terms of receiver chains and antenna elements. Direction-of-arrival estimation results are obtained using a high resolution SAGE algorithm. Measurement results show that the direction-of-arrival can be estimated with a reasonable accuracy in an indoor environment

Radio and IMU based indoor positioning and tracking

Navigation using inertial measurement units (IMUs) is an interesting area of research. Due to the low cost hardware and simple implementation, the approach looks very attractive. But the performance of the IMUs to provide sub-meter accuracy over a longer period of time is still not sufficient, so different approaches have been adopted to increase the performance at the cost of extra hardware and/or infrastructure. Our solution is based on the use of already existing radio infrastructure, where amplitude and phase variations in a received radio signal at the user terminal is used together with the IMU to do a tightly coupled estimation of navigation and radio signalmultipath components. The results show that the approach has the potential to enhance the performance of IMU based navigation significantly