UTHM water quality classification based on sub index

River or stream at their source is unpolluted, but as water flow downstream, the river or lake is receiving point and non-point pollutant source. Ammoniacal nitrogen (NH3- N) and suspended solids (SS) strongly influences the dynamics of the dissolved oxygen in the water. Studies on monitoring this parameter were conducted for a river or lake but limited to the small man-made lake. This study is initiate to determine the changes in water quality of UTHM watershed as the water flows from upstream to downstream. The monitoring of NH3-N and TSS were monitored at two sampling schemes, 1) at the two-week interval and, 2) at a daily basis followed by the determination of the water quality sub-index particularly SIAN and SISS. The results showed that the two lakes in UTHM watershed were classified as polluted. In conclusion, the remedial action should be implemented to improve the water quality to meet the requirements at least to meet the recreational purpose

Communication Subsystems for Emerging Wireless Technologies

The paper describes a multi-disciplinary design of modern communication systems. The design starts with the analysis of a system in order to define requirements on its individual components. The design exploits proper models of communication channels to adapt the systems to expected transmission conditions. Input filtering of signals both in the frequency domain and in the spatial domain is ensured by a properly designed antenna. Further signal processing (amplification and further filtering) is done by electronics circuits. Finally, signal processing techniques are applied to yield information about current properties of frequency spectrum and to distribute the transmission over free subcarrier channels

Signal Subspace Processing in the Beam Space of a True Time Delay Beamformer Bank

A number of techniques for Radio Frequency (RF) source location for wide bandwidth signals have been described that utilize coherent signal subspace processing, but often suffer from limitations such as the requirement for preliminary source location estimation, the need to apply the technique iteratively, computational expense or others. This dissertation examines a method that performs subspace processing of the data from a bank of true time delay beamformers. The spatial diversity of the beamformer bank alleviates the need for a preliminary estimate while simultaneously reducing the dimensionality of subsequent signal subspace processing resulting in computational efficiency. The pointing direction of the true time delay beams is independent of frequency, which results in a mapping from element space to beam space that is wide bandwidth in nature. This dissertation reviews previous methods, introduces the present method, presents simulation results that demonstrate the assertions, discusses an analysis of performance in relation to the Cramer-Rao Lower Bound (CRLB) with various levels of noise in the system, and discusses computational efficiency. One limitation of the method is that in practice it may be appropriate for systems that can tolerate a limited field of view. The application of Electronic Intelligence is one such application. This application is discussed as one that is appropriate for a method exhibiting high resolution of very wide bandwidth closely spaced sources and often does not require a wide field of view. In relation to system applications, this dissertation also discusses practical employment of the novel method in terms of antenna elements, arrays, platforms, engagement geometries, and other parameters. The true time delay beam space method is shown through modeling and simulation to be capable of resolving closely spaced very wideband sources over a relevant field of view in a single algorithmic pass, requiring no course preliminary estimation, and exhibiting low computational expense superior to many previous wideband coherent integration techniques

Signal Subspace Processing in the Beam Space of a True Time Delay Beamformer Bank

A number of techniques for Radio Frequency (RF) source location for wide bandwidth signals have been described that utilize coherent signal subspace processing, but often suffer from limitations such as the requirement for preliminary source location estimation, the need to apply the technique iteratively, computational expense or others. This dissertation examines a method that performs subspace processing of the data from a bank of true time delay beamformers. The spatial diversity of the beamformer bank alleviates the need for a preliminary estimate while simultaneously reducing the dimensionality of subsequent signal subspace processing resulting in computational efficiency. The pointing direction of the true time delay beams is independent of frequency, which results in a mapping from element space to beam space that is wide bandwidth in nature. This dissertation reviews previous methods, introduces the present method, presents simulation results that demonstrate the assertions, discusses an analysis of performance in relation to the Cramer-Rao Lower Bound (CRLB) with various levels of noise in the system, and discusses computational efficiency. One limitation of the method is that in practice it may be appropriate for systems that can tolerate a limited field of view. The application of Electronic Intelligence is one such application. This application is discussed as one that is appropriate for a method exhibiting high resolution of very wide bandwidth closely spaced sources and often does not require a wide field of view. In relation to system applications, this dissertation also discusses practical employment of the novel method in terms of antenna elements, arrays, platforms, engagement geometries, and other parameters. The true time delay beam space method is shown through modeling and simulation to be capable of resolving closely spaced very wideband sources over a relevant field of view in a single algorithmic pass, requiring no course preliminary estimation, and exhibiting low computational expense superior to many previous wideband coherent integration techniques

Radiation pattern synthesis in conformal antenna arrays using modified convex optimization technique

In this paper, a modified convex optimization technique is used for radiationpattern correction in a cylindrical-shaped conformal microstrip array antenna.The technique uses numerical simulations to optimize the amplitude andphase excitations, with the goal to decrease the Euclidean distance betweenthe desired field pattern and the obtained (simulated/measured) field patternwhile maintaining the main beam direction, null's location, and side lobelevels under control. Two prototypes of 1 4 and 2 4 conformal microstripantenna array deformed from linear/planar structure to the prescribed cylin-drical shape, with different radii of curvature, are studied to demonstrate theperformance of the proposed technique. The proposed convex optimizationmodel when applied to conformal antenna array possesses fast computingspeed and high convergence accuracy for radiation pattern synthesis, whichcan be a valuable tool for engineering applications.Dr. Mohammad Alibakhshikenari acknowledges supportfrom the CONEX-Plus programme funded by Universidad Carlos III de Madrid and the European Union's Horizon 2020 research and innovation programme under theMarie Sklodowska-Curie grant agreement No. 801538

Design of isofrequency reconfigurable repeaters

The advances in the communications systems has brought new requirements and challenges in terms of compactness and efficient systems that looking for increase the signal coverage area. The reconfigurable antennas are a promising solution for the communication systems when looking to improve the channel capacity and/or to extend the signal coverage. The main advantages of the reconfigurable antennas are the capabilities to change their frequency, polarization and radiation beam steering at a low cost. The reconfigurable antennas can be designed to operate in a determined changing environment keeping good electromagnetic characteristics. The design of reconfigurable RF repeaters is a relevant application of this reconfigurable antenna principle. This thesis is devoted to study and propose new repeater architectures in which a set of reconfigurable parasitic elements as part of the repeater are used for reducing the electromagnetic coupling between the Rx and Tx antennas. It is shown that the use of the parasitic elements as a reconfigurable mechanism gives the flexibility to adapt the repeater electromagnetic characteristics to changing environments while keeping a good system performance. The determination of the minimum number of parasitic elements is an important parameter and it is determined by a modal analysis to define the minimum number of parasitic elements able to fulfill specific repeater electromagnetic characteristics. In order to validate the analytical results, different reconfigurable repeater prototypes controlled electronically are manufactured. A reconfigurable repeater prototype that is using eight reconfigurable parasitic elements has been designed for operating at different scatterer environments. The repeater reconfigurable capabilities are studied to evaluate the repeater performance in realistic indoor locations. Finally, in order to obtain a repeater with reconfigurable frequency isolation capabilities between the Rx and Tx antennas over a wide frequency range, a repeater prototype based on a pixeled layer as reconfigurable mechanism has been designed and measured

Source localization within a uniform circular sensor array

Traditional source localization problems have been considered with linear and planar antenna arrays. In this research work, we assume that the sources are located within a uniformly spaced circular sensor array. Using a modified Metropolis algorithm and Polak-Ribière conjugate gradients, a hybrid optimization algorithm is proposed to localize sources within a two dimensional uniform circular sensor array, which suffers from far field attenuation. The developed algorithm is capable of accurately locating the position of a single, stationary source within 1% of a wavelength and 1° of angular displacement. In the single stationary source case, the simulated Cramer-Rao Lower Bound has also shown low noise susceptibility for a reasonable signal to noise ratio. Additionally, the localization of multiple stationary sources within the array is presented and tracking capabilities for a slowly moving non-stationary source is also demonstrated. In each case, results are presented, analyzed and discussed. Furthermore, the proposed algorithm has also been validated through hardware experimentation. The design and construction of four microstrip patch antennas and a wire antenna have been completed to emulate a circular sensor array and the enclosed source, respectively. Within this array, data has been collected at the four sensors from several fixed source positions and fitted into the proposed algorithm for source localization. The convergence of the algorithm with both simulated data and data collected from hardware are compared and sources of error and potential improvements are proposed

Aperture-Level Simultaneous Transmit and Receive (STAR) with Digital Phased Arrays

In the signal processing community, it has long been assumed that transmitting and receiving useful signals at the same time in the same frequency band at the same physical location was impossible. A number of insights in antenna design, analog hardware, and digital signal processing have allowed researchers to achieve simultaneous transmit and receive (STAR) capability, sometimes also referred to as in-band full-duplex (IBFD). All STAR systems must mitigate the interference in the receive channel caused by the signals emitted by the system. This poses a significant challenge because of the immense disparity in the power of the transmitted and received signals. As an analogy, imagine a person that wanted to be able to hear a whisper from across the room while screaming at the top of their lungs. The sound of their own voice would completely drown out the whisper. Approaches to increasing the isolation between the transmit and receive channels of a system attempt to successively reduce the magnitude of the transmitted interference at various points in the received signal processing chain. Many researchers believe that STAR cannot be achieved practically without some combination of modified antennas, analog self-interference cancellation hardware, digital adaptive beamforming, and digital self-interference cancellation. The aperture-level simultaneous transmit and receive (ALSTAR) paradigm confronts that assumption by creating isolation between transmit and receive subarrays in a phased array using only digital adaptive transmit and receive beamforming and digital self-interference cancellation. This dissertation explores the boundaries of performance for the ALSTAR architecture both in terms of isolation and in terms of spatial imaging resolution. It also makes significant strides towards practical ALSTAR implementation by determining the performance capabilities and computational costs of an adaptive beamforming and self-interference cancellation implementation inspired by the mathematical structure of the isolation performance limits and designed for real-time operation

WOAIP: Wireless Optimization Algorithm for Indoor Placement Based on Binary Particle Swarm Optimization (BPSO)

تحسين نشر نقطة الوصول (AP) له دور كبير في التطبيقات اللاسلكية بسبب الحاجة إلى توفير اتصال فعال بتكاليف نشر منخفضة. تقترح هذه الدراسة التحقيق في خوارزمية تحسين متعددة المستويات تسمى خوارزمية التحسين اللاسلكي للوضع الداخلي (WOAIP) استنادًا إلى تحسين حشد الجسيمات الثنائية (BPSO). يهدف WOAIP إلى الحصول على وضع AP الأمثل متعدد الطوابق مع تغطية فعالة تجعله أكثر قدرة على دعم جودة الخدمة (QoS). تم أخذ خمسة أزواج (التغطية ، نشر AP) من الأوزان ، عتبات الإشارة وقياسات قوة الإشارة المستقبلة (RSS) المحاكية باستخدام برنامج Wireless InSite (WI) في دراسة حالة الاختبار. من خلال مقارنة النتائج التي تم جمعها من WI مع نشر AP المادي المحاكي اللاسلكي الحالي للمبنى المستهدف - قسم علوم الحاسوب في جامعة بغداد. يُظهر تقييم أداء WOAIP زيادة من حيث موضع AP والتحسين المميز من أجل زيادة نسبة التغطية اللاسلكية إلى 92.93٪ مقارنة بـ 58.5٪ من تغطية AP الحالية (أو تحسين التغطية بنسبة 24.5٪ في المتوسط).Optimizing the Access Point (AP) deployment has a great role in wireless applications due to the need for providing an efficient communication with low deployment costs. Quality of Service (QoS), is a major significant parameter and objective to be considered along with AP placement as well the overall deployment cost. This study proposes and investigates a multi-level optimization algorithm called Wireless Optimization Algorithm for Indoor Placement (WOAIP) based on Binary Particle Swarm Optimization (BPSO). WOAIP aims to obtain the optimum AP multi-floor placement with effective coverage that makes it more capable of supporting QoS and cost-effectiveness. Five pairs (coverage, AP deployment) of weights, signal thresholds and received signal strength (RSS) measurements simulated using Wireless InSite (WI) software were considered in the test case study by comparing the results collected from WI with the present wireless simulated physical AP deployment of the targeted building - Computer Science Department at University of Baghdad. The performance evaluation of WOAIP shows an increase in terms of AP placement and optimization distinguished in order to increase the wireless coverage ratio to 92.93% compared to 58.5% of present AP coverage (or 24.5% coverage enhancement on average)