Farah Nadia Mohd Isa

Preliminary antenna system design for FMCW avalanche radar

This paper described the design and construction of a preliminary microstrip array antenna at 5.3 GHz. The antenna is going to be applied to an FMCW avalanche radar. The antenna design which composed of an array of 4 × 2 patches could achieve the high gain of 15.6 dB with a wideband of 90%. The high gain and wideband attributes is also achieved by separating the feed network from the main patches and increasing the antenna height. In order to ensure the power is transferred smoothly from the main input port, the feed network is designed in a nover spider-like tapered feed while ensuring the antenna performance is not affected.

An Improved Component Carrier Selection Algorithm for Downlink Long Term Evolution-Advanced

Long Term Evolution-Advanced (LTE-A) supports much wider transmission bandwidth through Carrier Aggregation (CA). CA is a method that aggregates multiple Component Carriers (CCs) of the same or different frequency bands. Additionally, LTE-A system needs to simultaneously support a mixture of LTE-A and Long Term Evolution (LTE) users. The LTE-A users can transmit on multiple CCs whereas the LTE users are restricted to transmit on a single CC. Given that there are multiple CCs available, an efficient CC selection algorithm is necessary in order to assign a CC to each LTE user. This paper proposes a novel CC selection algorithm to efficiently utilize the available radio resources whilst balancing total load across multiple CCs. Results obtained via simulation have demonstrated the efficacy of the proposed algorithm in optimizing the system capacity without compromising the Quality of Service (QoS) requirements of delay-sensitive Guaranteed Bit Rate (GBR) application.

Design of high gain microstrip Yagi array antenna for avalanche radar

This paper presents the design and construction of a microstrip Yagi array antenna operating at 5.3 GHz, to be used with an avalanche sensor in avalanche measurement. The advantage of the antenna is it can achieve a high gain of 15.2 dB with bandwidth of 8% in compact size. The gain enhancement is achieved by using a compact microstrip Yagi antenna as the array element; separating the feed network from the main radiating elements; and increasing the antenna height by installing the feed layer at the back of the patch layer, sharing the same ground plane. In order to ensure the power is transferred smoothly from the main input port to the radiating elements, the corporate feed is also design and tested. The fabricated antenna shows an agreeable performance with the simulated version.

Investigations of Component Carrier Selection Algorithms in Long Term Evolution-Advanced

Received Jan 15, 2018 Revised Mar 14, 2018 Accepted Mar 30, 2018 Blood veins detection process can be cumbersome for nurses and medical practioners when it comes to special overweight type of patients. This simple routine procedure can lead the process into an extreme calamity for these patients. In this paper, we emphasized on a process for the detection of the vein in real time using the consecrations of Matlab to prevent or at least reduce the number of inescapable calamity for patients during the infusion of a needle by phlebotomy or doctor in everyday lives. Hemoglobin of the blood tissues engrossed the Near Infrared (NIR) illuminated light and Night vision camera is used to capture the scene and enhance the vein pattern clearly using Contrast Limited Adaptive Histogram Equalization (CLAHE) method. This simple approach can successfully also lead to localizing bleeding spots, clots from stroke ... etc among other things.

Improving real-time multimedia scheduling in practical mobile cellular channels

The demand for real-time multimedia applications has been exponentially increased these days. Long Term Evolution-Advanced (LTE-A) is one of the mobile cellular technologies envisaged to provide good real-time multimedia experiences. However, real-time multimedia scheduling over the downlink LTE-A is a subject to various impairments. This paper adapts the well-known single-carrier Maximum-Largest Delay First (M-LWDF) algorithm into practical multi-carrier downlink LTE-A so as to minimize the detrimental effects of mobile cellular channel impairments on the real-time multimedia experiences. Simulation results demonstrated the efficacy of the adapted M-LWDF algorithm where it provides good experiences for more users and is more robust in case of outdated channel quality information report.

FMCW Radar for Slow Moving Target Detection: Design and Performance Analysis

This paper discusses the design and performance of a Frequency Modulated Continuous Wave (FMCW) Radar Doppler for slow moving target detection. It is modeled as a lowcost and feasible radar remote sensor for measuring particular moving targets range and velocity. It operates at ISM band with a center frequency of 2.4GHz, transmit power of approximately 11.3dBm and 52MHz transmit signal bandwidth. The radar also employs linear FM waveform, bistatic antenna system, and Doppler mode operation. The radar hardware architecture is built by assembling off-shelf electronic devices and tested towards slow moving target in a Microwave Laboratory. The target that is used to evaluate and analyze the radar performance is a human body which moves at different speeds over time. The analysis demonstrates that the proposed radar system capable of detecting and measuring the targets velocity and range. Besides, the radar system demonstrates that it can measure min velocity of 0.77 m/s for the short range moving target.

Frequency Modulated Continuous Wave Radar Modeling for Landslide Detection in Malaysia

Landslide is one of natural hazards that is frequently happen after continuous heavy rainfall especially during monsoon season. It effects serious damages on property and also treat human being’s live. The objective of this paper is to design and evaluate the performance of a Frequency Modulated Continuous Wave (FMCW) radar for detecting of slow moving landslide movements in Malaysia. The performance of the proposed radar design is tested by using Agilent Advanced Design System (ADS) software. It operates at 2.4 GHz carrier frequency with a resolution range of 0.75 m. Its signal power increases around 38 dBm after de-ramping process. Hence, it increases the sensitivity of the radar to detect the landslide occurrences. The radar has capability to detect landslide movements of 20 m/s speed.

Fade Margin Estimation Technique Using Radar Data for Satellite Link

The fade margin is an important parameter used by the operator to measure the link availability for a given time. Fade margin is a parameter that is used in the design of satellite links to ensure optimal performance of the link. A new technique is proposed where the fade margin of a satellite link can be estimated using attenuation statistics of radar data. Data set acquired from Malaysian meteorological radar for the year 2009 is used in the study. Radar return or reflectivity is used in the process of generating the attenuation values. The reflectivity is first converted into rainfall rate value and the specific attenuation is then calculated. The rain attenuation values can be derived by the multiplication of the specific attenuation and the path length affected. The rainfall rate derived from radar information is used in calculating the slant path attenuation of the satellite link. The databases of rain attenuation is then compiled with the time duration to acquire the cumulative distribution function (CDF) for the specified link. The satellite link investigated are based on the RazakSAT link in relation to its ground station located at Sg Lang, Banting, Selangor, Malaysia for X-band and MEASAT-3 satellite in relation to its ground station at Cyberjaya, Selangor, Malaysia for Ku-band.

Analysis of sparsely sampled phased array antenna for advanced Doppler radar

This paper documents the study of a sparsely sampled phased array antenna used for an avalanche radar in VDLS. The fully populated array of 144 elements (16 × 9) is analysed and some of the prominent result are tabulated in this paper findings. The thinning method is based on the previous knowledge of the iterative method compiled by the author. It is shown that with the right thinning of the antenna elements, the beampattern of the phased array antenna could be controlled to give the desired pattern to the designer.

Prediction of Rain-Induced Cross Polarization at Millimeter Wave Bands in Guinea

Microwave communication systems are planned to utilize orthogonal polarization. Two independent information channels of the same frequency band sent over a single link to make an optimum use of the frequency spectrum. However, above 10 GHz, the amount of rain on the transmission line can severely degrade the performance of both satellite and terrestrial links, especially in tropical regions, at millimetre wave bands. This paper evaluates the differential attenuation and differential phase shift for the prediction of cross polarization discrimination using a 10-year rain data recorded in Conakry, Guinea. The drop size distribution (DSD) was computed using Marshall and Palmer (MP) model.