Azmi Awang Md Isa

Simulation of virtual MIMO base stations for mobile location in IMT-Advanced networks

The conventional Location and Positioning (L&P) methods rely on availability of base station (BS) locations as well as mitigation of propagation effects. It is known that the location estimation accuracy suffers from poor geometric dilution of precision (GDOP) caused by BS location as the conventional location algorithms which result in large GDOP values correspond to poor geometrical topology. In addition, NLOS effects cause a large error in time of arrival (TOA) reading; thus affecting mobile station (MS) estimation accuracy. In this paper a novel concept of virtual BS (VirBS) utilizing multiple input multiple output (MIMO) technology has been introduced and applied for improving L&P accuracy. The performance of the proposed algorithm has been evaluated via computer simulations. The simulation results demonstrate that the proposed algorithm allows up to 30 percent improvement in L&P accuracy without additional expenditure on network architecture.

Wireless Location Positioning Based on WiMAX Features - A Preliminary Study

In 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.

A compact DMS triple-band bandstop filter with U-slots for communication systems

This paper presents compact structure of bandstop filter with Defected Microstrip Structure (DMS) to produce a triple - band reject response. To prove the concept of the narrow notched DMS, the operating on centre frequency of 4.0 GHz is demonstrated and validated through simulation. The DMS structure is embedded in the middle of transmission lines in order to reject any undesired signals which may interfere with any communication systems. The design was simulated based on Roger Duroid RO4350B with a thickness of 0.508 mm and dielectric constant of 3.48. This type of filter is useful in any RF/ microwave communication systems, particularly to eliminate any undesired signals in wideband spectrum. While maintaining its excellent performance, the overall physical and cost reduction can also be achieved using this technique.

Utilising MIMO for positioning in mobile WiMAX systems

Worldwide interoperability for microwave access (WiMAX) brings additional features that can be utilized for enhancing positioning accuracy. This paper deals with WiMAX positioning scheme based on the first arrival path (FAP) of the time of arrival (TOA) technique by utilising one of WiMAX offered features i.e multiple input multiple output (MIMO) system. Simulation results show that the performance of system in term of the positioning accuracy adheres to the Federal Communications Commission (FCC) requirements.

High-Efficiency Microwave Planar Resonator Sensor Based on Bridge Split Ring Topology

This letter presents a high efficiency and accurate measurement of microwave resonator sensor using microstrip planar structural technology. The structure is designed based on the bridge split ring topology. The sensor has the ability to characterize liquid solvents using the extraction of polynomial fitting technique. The bridge equivalent circuit configuration allows the electromagnetic wave to focus on the sensing medium in order to gain high electric flux density, thus react as pushing effect for high Q factor. The bridge structure amplifies the electric field distribution. As demonstrated by the results, the unloaded

A novel technique of controlling signal propagation within array elements using switchable miniaturized electromagnetic band gap

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Current developments in LTE-ADVANCED: Radio resource management review

-factor improves more than 400 over the narrow bandwidth at operating frequency of 2.3 GHz, and provides less than 10-dB insertion loss. By comparison, this design has an identical performance goal and provides excellent sensing capability which can be implemented in pharmaceutical, biomedical, and beverage industries application.

Eye closure and open detection using Adaptive Thresholding Histogram Enhancement (ATHE) technique and connected components utilisation

In this paper, a novel miniaturized capacitive loaded electromagnetic band gap (EBG) has been developed with the patch size of approximately)./36. The dimension is controllable using the lumped capacitive elements values. The surface impedance characteristic of the EBG structure is switchable as pin vias have been inserted and removed within the EBG center and the ground plane. Switching the EBG surface impedance characteristic within the array elements has demonstrated the novel application of miniaturized EBG to control the signal propagation within the array elements. Radiation pattern for the middle antenna is enhanced toward the antenna which connected with low surface impedance EBG structure resulting approximately 12dB improvement in gain. The propagation characteristics and gain of the array have been analyzed using CST Microwave Studio (CST MWS). The new application of the EBG can be very useful to realize the controlling and channeling the signal within the array elements.

Utilising MIMO for location and positioning in IMT-advanced systems

This paper provides a review of current technology components currently used by OFDMA-based Long Term Evolution-Advanced (LTE-Advanced). LTE-Advanced significantly enhanced the previous versions of LTE Release 8/9 to support higher data rates and wider coverage resulting in best experience for users. Some of the technologies discussed in this paper are enhanced Multiple Input Multiple Output (MIMO), advanced repeaters or known as relaying systems, coordinated multipoint transmission/reception and carrier aggregation to expand the capability of the bandwidth spectrum. Among the issues addressed in this paper are related to balancing of transmit power control for both base stations and relay stations and also frequency spectrum allocation in order to avoid any interference within a mobile cell. This also includes how to manage different types of interferences such as intercell interference, intersymbol and intercarrier interferences in the LTE-Advanced system.

Mobile prayer times and Qiblat direction using GPS

Eye 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.