Design of antenna array and data streaming platform for low-cost smart antenna systems

The wide range of wireless infrastructures such as cellular base stations, wireless hotspots, roadside infrastructures, and wireless mobile infrastructures have been increasing rapidly over the past decades. In the transportation sector, wireless technology refreshes require constantly introducing newer wireless standards into the existing wireless infrastructure. Different wireless standards are expected to co-exist, and the air space congestion worsens if the wireless devices are operating in different wireless standards, where collision avoidance and transmission time synchronisation become complex and almost impossible. Huge challenges are expected such as operation constraints, cross-system interference, and air space congestion. Future proof and scalable smart wireless infrastructures are crucial to harmonise the un-coordinated wireless infrastructures and improve the performance, reliability, and availably of the wireless networks. This thesis presents the detailed design of a novel pre-configurable smart antenna system and its sub-system including antenna element, antenna array, and radio frequency (RF) frontend. Three types of 90° beamforming antenna array (with low, middle and high gain) were designed, simulated, and experimentally evaluated. The RF frontend module or transmit and receive (T/R) module was designed and fabricated. The performance of the T/R module was characterised and calibrated using the recursive calibration method, and drastic sidelobe level (SLL) improvement was achieved using the amplitude distribution technique. Finally, the antenna arrays and T/R modules are integrated into the pre-configurable smart antenna system, the beam steering performance is experimentally evaluated and presented in this thesis. With the combination of practical know-how and theoretical estimation, the thesis highlights how the modern smart antenna techniques that support most cutting-edge wireless technology can be adopted into the existing infrastructure with minimum distraction to the existing systems. This is in line with the global Smart City initiative, where a huge number of Internet of Things (IoT) devices being wired, or wireless are expected to work harmoniously in the same premises. The concept of the pre-configurable smart antenna system presented in this thesis is set to deliver a future-proof and highly scalable and sustainable infrastructure in the transportation market

A Flexible Low-Cost Hybrid Beamforming Structure for Practical Beamforming Applications

In this paper, a simplified yet flexible half-duplex hybrid beamforming (HBF) architecture along with the adaptive beam scanning and direction-finding methodology for the 360° HBF system has been proposed. The structure is constructed using up to 4 units of n × 4 antenna arrays with choice of gain and coverage sector, which is powered by only 4 RF beamforming chains. In addition, the flexible beamforming structure is able to enable beamforming function of any legacy transceiver. The proposed architecture exhibits prominent advantages in reducing the hardware complexity and cost of the HBF system by 4 folds and offers the field-friendly feature with the flexible gain and coverage concept that allow only the necessary array to be installed

A Wideband Beam Forming Antenna Array for 802.11ac and 4.9 GHz

In this work, a wideband high gain 1×4 beamforming (BF) antenna array has been proposed for 5.17 - 5.85 GHz ISM band and extended coverage for 4.92 - 4.98 GHz licensed band. The key antenna performances of 13.6 dBi realized gain, 24.4° Beamwidth, 12.9 dB Sidelobe at 0° beam and ±40° beam steering capability has been achieved. The proposed antenna intended to provide the enhanced wireless link between the ground base station and the mobile terminals with beamforming concept that allow beam steering to focus on targeted direction and null the interference direction with small beam width. The proposed antenna can be further re-configured with different gain and steering beam to cater the dynamic transportation environments

A Smart and Low-cost Enhanced Antenna System for Industrial Wireless Broadband Communication

The aim of this paper is to investigate the traditional wireless local area network (LAN) deployment methods, challenges, and proposal of a novel smart antenna technique to mitigate the problems. In this paper, the focus is on the wireless link between cars to the road-side base station or trains to the trackside base station with fixed access point serving multiple mobile clients. A low-cost, highly scalable, long-range, half duplex hybrid smart antenna architecture with capability of direction of arrival (DOA) estimation and adaptive beamforming integration is proposed. The deployment cell size simulation result shows a drastic reduction in the number of equipment needed to cover the same service area as compared to the traditional method. The results will be of great importance for the future wireless deployment in the transportation market, knowing that the installation cost and maintenance cost are a major cost factor

Design and characterization of T/R module for commercial beamforming applications

In the smart antenna system, the transmit and receive (T/R) module is one of the core components as it accounts for nearly 45% of the overall smart antenna system cost. Due to the high implementation cost of the T/R module, the literature was mainly centered around the military and satellite radar applications. However, over the years, the cost of the T/R module has been reduced drastically by leveraging on the advanced manufacturing technology, volume production pricing and adaptation of the commercially available off-the-shelf components, as a result, the adoption of the T/R module in commercial and industrial application become possible. In this work, we have proposed a commercially affordable T/R module that operates in 4.9 – 5.9 GHz band for commercial and industrial applications. The T/R module was designed, calibrated, and characterized for use in the beamforming smart antenna system. The design process including the circuit, schematic and printed circuit board (PCB) were highlighted. The proposed recursive calibration process managed to correct the phase error to ± 1° and amplitude error to ± 0.2 dB. In addition, the amplitude distribution of 0.5-1-1-0.5 combination has successfully suppressed the side-lobe level (SLL) to -28.7 dB for 0°, -22.71 dB for ± 20° and -12.77 dB for ± 40° beam steering. This work is aimed to promote the adoption of the T/R module into the commercial and industrial applications such as public or government infrastructure

A wideband beamforming antenna array for 802.11ac and 4.9 GHz in modern transportation market

In this work, a novel antenna structure has been proposed, which consists of multiple sub-array features i.e., a field selectable beam (90°, 180°, 270°, and 360°) and the choice of gain (11.16, 14.59 and 17.25 dBi) that can be easily adapted to cater for the dynamic scenarios in the transportation environment. The sub-arrays were designed using the microstrip patch antenna (MPA) concept with capacitive feed and dual substrate stacked up configuration for superior operating bandwidth covering the entire 802.11ac (5.17 to 5.85 GHz Industrial Scientific and Medical (ISM) band), in addition to the extended coverage for 4.92 to 4.98 GHz licensed band with narrow azimuth beamwidth of 24°. The sub-array was designed, simulated and experimentally evaluated and the beamforming results revealed that the antenna structure can be integrated with beamforming concepts to provide an enhanced wireless link between the ground base station and the mobile terminals that allows beam steering to focus on the targeted direction and null the interference directions with small beam width. It is expected that the proposed configurable gain/beam beamforming antenna array will further reduce the deployment cost and enhance the anti-interference performance by two-fold, and shall bring the user experience in the transportation market to the next level

An antenna array with enhanced gain and bandwidth for 802.11ac and 4.9GHz beamforming applications

No abstract available

Sensor Aided Beamforming in Vehicular Environment

Sensor fusion is a well-known technique to harvest the raw data from various type of sensors and generate a more accurate prediction on certain operation parameters that helps to improve the accuracy and efficiency of a big system. Many industries have been benefited from the sensor fusion such as robotic, agriculture, healthcare, autonomous vehicle, navigation and so on. In the smart antenna industry, the conventional beamforming is implemented in the costly field programmable grid array (FPGA) platform with the complex direction of arrival (DOA) algorithm. In this work, we are presenting a feasibility study on a lower cost alternative called sensor aided beamforming that make use of the raw data from the existing sensors in the vehicle, combined with some simple mathematically calculation to determine the beam angle of the mobile client and roadside infrastructure. We have presented a practical approach to study the sensor aided beamforming system in the real environment by simulating the beamforming parameters for a moving vehicle moves along the road that was pre-installed with roadside access points (AP). The result has proofed that the sensor aided method can be used to realize the beamforming in the smart antenna system, with the IoT sensors cost approximately less than U20comparedwiththeFPGApricerangeofaroundU200, the sensor aided beamforming will be a cheaper and affordable alternative to the conventional beamforming system that usually realized with the complex direction of arrival algorithm and higher cost

An Amplitude Distribution Network in the T/R Module for Beamforming Applications

To catch up with the rapid technology changing trend in the smart antenna industry, the modular design approach is inevitable amongst the researchers and manufacturers to maintain their competitiveness in term of cost and technology adoption. In the smart antenna system, the modular approach has gained its popularity, particularly the building block such as transmit and receive (T/R) module which is complex and subjected to upgrade due to its components upgrade and technology improvement over the time. Amplitude Distribution in the beamforming antenna array system is crucial to achieve the optimum antenna radiation performance such as gain, half-power beamwidth (HPBW), side lobe level (SLL) etc. The highly flexible and scalable T/R module with Amplitude distribution network has been proposed, the Amplitude Distribution for the linear array can be easily simulated using Computer Simulation Technology (CST) tools eliminating the needs of going through the complex and time-consuming mathematical analysis approach. The Amplitude Distribution has been simulated using CST tools and the performance was validated using the T/R module with the 4×4 array

A Recursive Calibration Approach for Smart Antenna Beamforming Frontend

In this work, a simple iteration-based approach is proposed for calibration and characterization of the frequency, phase and transmit power relationship in a smart antenna Radio Frequency (RF) beamforming frontend, which has a very low computational complexity. The RF frontend has been experimentally calibrated, and the beamforming results are verified with the 4×4 phased array. The RF frontend has been built using off-the-shelf components for easy realization. The proposed architecture with the closed-loop monitoring and control such as the power control (Pctrl), power detection (Pdet), in addition to the phase control allows an automatic calibration of the beamforming weights, which forms a necessary process to ensure the accuracy of the antenna array beamforming