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XUE JUN LI (IEEE senior member) received B.Eng. (Hons.) and Ph.D. degrees in electrical and electronic engineering from Nanyang Technological University (NTU), Singapore, in 2004 and 2008, respectively. From November 2007 to July 2008, he was as a Research Engineer and a Research Fellow at the Network Technology Research Centre, NTU. From August 2008 to September 2008, he was a Research Scientist at Temasek Laboratories, NTU. From September 2008 to May 2011, he was a Faculty Member at the School of Electrical and Electronic Engineering, NTU. From June 2011 to January 2013, he was a Research Scientist at the Institute for Infocomm Research (I2R), Agency for Science, Technology and Research (A*STAR), Singapore. Since January 2013, he has been a Senior Lecturer at the Department of Electrical and Electronic Engineering, School of Engineering, Auckland University of Technology (AUT). His research interests include design/analysis of wireless networking protocols, modeling/design of radio frequency integrate circuits, and system optimizations.
A compact frequency reconfigurable printed antenna for millimeter-wave applications is presented in this paper. This design is obtained by the merging of a half-arc and a right-angled triangle patch extracted from a rectangular radiator. The design approach is based on the use of two S-PIN diodes to obtain frequency reconfigurability. The antenna exhibits seven reconfigurable bands while showing good performances in terms of return loss, bandwidth and gain. The proposed antenna is well suited for future fifth-generation (5G) networks because of its notable features of small overall size (7.5 \(\times\) 5 \(\times\) 0.762 mm3), wide bandwidth, and frequency reconfigurability.
Wahaj Abbas Awan; Niamat Hussain; Adnan Ghaffar; SyedaIffat Naqvi; Abir Zaidi; Musa Hussain; Xue Jun Li. A Low Profile Frequency Reconfigurable Antenna for mmWave Applications. Lecture Notes in Electrical Engineering 2021, 1073 -1083.
AMA StyleWahaj Abbas Awan, Niamat Hussain, Adnan Ghaffar, SyedaIffat Naqvi, Abir Zaidi, Musa Hussain, Xue Jun Li. A Low Profile Frequency Reconfigurable Antenna for mmWave Applications. Lecture Notes in Electrical Engineering. 2021; ():1073-1083.
Chicago/Turabian StyleWahaj Abbas Awan; Niamat Hussain; Adnan Ghaffar; SyedaIffat Naqvi; Abir Zaidi; Musa Hussain; Xue Jun Li. 2021. "A Low Profile Frequency Reconfigurable Antenna for mmWave Applications." Lecture Notes in Electrical Engineering , no. : 1073-1083.
This paper presents the design and realization of a compact frequency reconfigurable antenna for multiband wireless applications. The antenna can operate at overall eight different bands in four dual-band modes. A slot in the radiator and defected ground structure are utilized to achieve a compact size, while PIN diodes are used for frequency reconfigurability in the proposed antenna. The antenna shows broad bandwidth in each operating frequency and has a compact size of 18 mm × 18 mm × 1.524 mm. Moreover, stable radiation patterns and a high value of efficiency make it a potential candidate for various wireless applications. Furthermore, to demonstrate the worth of this work, its performance is compared with state-of-the-art designs reported for similar applications.
Adnan Ghaffar; Wahaj Awan; Niamat Hussain; Xue-Jun Li. A Compact Octa-Band Frequency Reconfigurable Antenna for Wireless Applications. Mathematics 2021, 9, 1557 .
AMA StyleAdnan Ghaffar, Wahaj Awan, Niamat Hussain, Xue-Jun Li. A Compact Octa-Band Frequency Reconfigurable Antenna for Wireless Applications. Mathematics. 2021; 9 (13):1557.
Chicago/Turabian StyleAdnan Ghaffar; Wahaj Awan; Niamat Hussain; Xue-Jun Li. 2021. "A Compact Octa-Band Frequency Reconfigurable Antenna for Wireless Applications." Mathematics 9, no. 13: 1557.
A reconfigurable
Shilpa Mehta; Xue-Jun Li; Massimo Donelli. Design and Analysis of a Reconfigurable Gilbert Mixer for Software-Defined Radios. Sensors 2021, 21, 2711 .
AMA StyleShilpa Mehta, Xue-Jun Li, Massimo Donelli. Design and Analysis of a Reconfigurable Gilbert Mixer for Software-Defined Radios. Sensors. 2021; 21 (8):2711.
Chicago/Turabian StyleShilpa Mehta; Xue-Jun Li; Massimo Donelli. 2021. "Design and Analysis of a Reconfigurable Gilbert Mixer for Software-Defined Radios." Sensors 21, no. 8: 2711.
This research article proposes a compact frequency and pattern reconfigurable flexible antenna for heterogeneous applications. A triangular monopole antenna with a semicircular stub is made frequency and pattern tunable by connecting and disconnecting two inverted L-shaped stubs utilizing diodes. When either of the stubs is connected to the radiator, a relative phase difference happens at both ends of the radiator that changes the direction of the electromagnetic radiations, consequently pattern reconfigurability can be obtain. Besides that, because of the reactive load introduced by the stubs, the antenna’s effective length has changed and, as a result, the frequency reconfigurability can be attained. The antenna features a compact size of 40 × 50 × 0.254 mm3 corresponding to 0.22λo × 0.27λo × 0.001λo, where λo is free-space wavelength at 1.65 GHz, while its operational bandwidth is from 1.65 GHz to 2.51 GHz, with an average gain and radiation efficiency of better than 2.2 dBi and 80%, exhibiting a pattern reconfigurability of 180° in the E-plane. The frequency of the proposed antenna can be switched from 2.1 GHz to 1.8 GHz by switching the state of both diodes in OFF and ON-state, respectively. The fabricated prototype of the antenna is tested to verify its performance parameters. In addition, to validate the proposed design, it has been compared with prior arts in terms of the overall size, reconfigurability type, flexibility, radio frequency (RF) switch type used for reconfigurability, and frequency bandwidth. The proposed antenna provides smaller size with a large bandwidth coverage alongside with discrete RF switch type with the advantages of flexibility and both frequency and pattern reconfigurability. As a result, the proposed compact flexible and pattern reconfigurable antenna is a promising candidate for heterogeneous applications, including the global system for mobile (GSM) band (1800 and 1900 MHz) and industrial, scientific and medical (ISM) band (2.4 GHz) along with well-known cellular communication bands of 3G, 4G, and long term evolution (LTE) bands ranging from 1700–2300 MHz around the globe.
Adnan Ghaffar; Xue Li; Wahaj Awan; Aqeel Naqvi; Niamat Hussain; Mohammad Alibakhshikenari; Ernesto Limiti. A Flexible and Pattern Reconfigurable Antenna with Small Dimensions and Simple Layout for Wireless Communication Systems Operating over 1.65–2.51 GHz. Electronics 2021, 10, 601 .
AMA StyleAdnan Ghaffar, Xue Li, Wahaj Awan, Aqeel Naqvi, Niamat Hussain, Mohammad Alibakhshikenari, Ernesto Limiti. A Flexible and Pattern Reconfigurable Antenna with Small Dimensions and Simple Layout for Wireless Communication Systems Operating over 1.65–2.51 GHz. Electronics. 2021; 10 (5):601.
Chicago/Turabian StyleAdnan Ghaffar; Xue Li; Wahaj Awan; Aqeel Naqvi; Niamat Hussain; Mohammad Alibakhshikenari; Ernesto Limiti. 2021. "A Flexible and Pattern Reconfigurable Antenna with Small Dimensions and Simple Layout for Wireless Communication Systems Operating over 1.65–2.51 GHz." Electronics 10, no. 5: 601.
This paper presents the design and implementation of a dual-band low noise amplifier (DBLNA) operating at 1.1 GHz and 2.4 GHz. The DBLNA employs a second-order dual-band matching network, which is designed using the proposed impedance and frequency transformation technique. The DBLNA has two stages in cascade topology for its high output impedance and high voltage gain. Modified output load is designed to optimize interference rejection. The implemented circuit is fabricated as a microwave integrated circuit (MIC) on the FR-4 substrate. The designed DBLNA achieves a very high measured voltage gain of 24.4 dB and 20.1 dB at 1.1 GHz and 2.4 GHz, respectively. The measured NF of the DBLNA is 2.6 dB and 3 dB at 1.1 GHz and 2.4 GHz, respectively. The interference rejection between passbands at 1.6 GHz is 53.2 dB and stopband rejection ratio is 40.4 dB. The LNA consumes 108 mW from a 3 V supply. The measured P1dB performance is −10 dBm and −5.1 dBm at 1.1 GHz and 2.4 GHz, respectively.
Aayush Aneja; Xue Jun Li; Peter Han Joo Chong. Design and analysis of a 1.1 and 2.4 GHz concurrent dual-band low noise amplifier for multiband radios. AEU - International Journal of Electronics and Communications 2021, 134, 153654 .
AMA StyleAayush Aneja, Xue Jun Li, Peter Han Joo Chong. Design and analysis of a 1.1 and 2.4 GHz concurrent dual-band low noise amplifier for multiband radios. AEU - International Journal of Electronics and Communications. 2021; 134 ():153654.
Chicago/Turabian StyleAayush Aneja; Xue Jun Li; Peter Han Joo Chong. 2021. "Design and analysis of a 1.1 and 2.4 GHz concurrent dual-band low noise amplifier for multiband radios." AEU - International Journal of Electronics and Communications 134, no. : 153654.
This paper presents the design and realization of a compact size multimode frequency reconfigurable antenna. The antenna consists of a triangular-shaped monopole radiator, originally inspired from a rectangular monopole antenna. Slots were utilized to notch the desired frequency while the PIN diodes were utilized to achieve frequency reconfigurability. The antenna can operate in wideband, dual-band, or tri-band mode depending upon the state of the diodes. To validate the simulation results, a prototype was fabricated, and various performance parameters were measured and compared with simulated results. The strong agreement between simulated and measured results along with superior performance as compared to existing works in the literature makes the proposed antenna a strong candidate for ISM, 5G-sub-6 GHz, and S-band applications.
Adnan Ghaffar; Xue Li; Wahaj Abbas Awan; Syeda Iffat Naqvi; Niamat Hussain; Boon Chong Seet; Mohammad Alibakhshikenari; Francisco Falcone; Ernesto Limiti. Design and Realization of a Frequency Reconfigurable Multimode Antenna for ISM, 5G-Sub-6-GHz, and S-Band Applications. Applied Sciences 2021, 11, 1635 .
AMA StyleAdnan Ghaffar, Xue Li, Wahaj Abbas Awan, Syeda Iffat Naqvi, Niamat Hussain, Boon Chong Seet, Mohammad Alibakhshikenari, Francisco Falcone, Ernesto Limiti. Design and Realization of a Frequency Reconfigurable Multimode Antenna for ISM, 5G-Sub-6-GHz, and S-Band Applications. Applied Sciences. 2021; 11 (4):1635.
Chicago/Turabian StyleAdnan Ghaffar; Xue Li; Wahaj Abbas Awan; Syeda Iffat Naqvi; Niamat Hussain; Boon Chong Seet; Mohammad Alibakhshikenari; Francisco Falcone; Ernesto Limiti. 2021. "Design and Realization of a Frequency Reconfigurable Multimode Antenna for ISM, 5G-Sub-6-GHz, and S-Band Applications." Applied Sciences 11, no. 4: 1635.
In this article, a novel metamaterial inspired UWB/multiple-input-multiple-output (MIMO) antenna is presented. The proposed antenna consists of a circular metallic part which formed the patch and a partial ground plane. Metamaterial structure is loaded at the top side of the patches for bandwidth improvement and mutual coupling reduction. The proposed antenna provides UWB mode of operation from 2.6–12 GHz. The characteristic mode theory is applied to examine each physical mode of the antenna aperture and access its many physical parameters without exciting the antenna. Mode 2 was the dominant mode among the three modes used. Considering the almost inevitable presence of mutual coupling effects within compact multiport antennas, we developed an additional decoupling technique in the form of perturbed stubs, which leads to a mutual coupling reduction of less than 20 dB. Finally, different performance parameters of the system, such as envelope correlation coefficient (ECC), channel capacity loss (CCL), diversity gain, total active reflection coefficient (TARC), mean effective gain (MEG), surface current, and radiation pattern, are presented. A prototype antenna is fabricated and measured for validation.
Adamu Jabire; Adnan Ghaffar; Xue Li; Anas Abdu; Sani Saminu; Mohammad Alibakhshikenari; Francisco Falcone; Ernesto Limiti. Metamaterial Based Design of Compact UWB/MIMO Monopoles Antenna with Characteristic Mode Analysis. Applied Sciences 2021, 11, 1542 .
AMA StyleAdamu Jabire, Adnan Ghaffar, Xue Li, Anas Abdu, Sani Saminu, Mohammad Alibakhshikenari, Francisco Falcone, Ernesto Limiti. Metamaterial Based Design of Compact UWB/MIMO Monopoles Antenna with Characteristic Mode Analysis. Applied Sciences. 2021; 11 (4):1542.
Chicago/Turabian StyleAdamu Jabire; Adnan Ghaffar; Xue Li; Anas Abdu; Sani Saminu; Mohammad Alibakhshikenari; Francisco Falcone; Ernesto Limiti. 2021. "Metamaterial Based Design of Compact UWB/MIMO Monopoles Antenna with Characteristic Mode Analysis." Applied Sciences 11, no. 4: 1542.
In recent years, there has been a big data revolution in smart cities dues to multiple disciplines such as smart healthcare, smart transportation, and smart community. However, most services in these areas of smart cities have become data-driven, thus generating big data that require sharing, storing, processing, and analysis, which ultimately consumes massive amounts of energy. The accumulation process of these data from different areas of a smart city is a challenging issue. Therefore, researchers have started aiming at the Internet of vehicles (IoV), in which smart vehicles are equipped with computing and storage capabilities to communicate with surrounding infrastructure. In this paper, we propose a subcategory of IoV as the Internet of buses (IoB), where public buses enable a service as a data carrier in a smart city by introducing a neural network-based sustainable data dissemination system (NESUDA), where opportunistic sensing comprises delay-tolerant data collection, processing and disseminating from one place to another place around the city. The objective was to use public transport to carry data from one place to another and to reduce the traffic from traditional networks and energy consumption. An advanced neural network (NN) algorithm was applied to locate the realistic arrival time of public buses for data allocation. We used the Auckland transport (AT) buses data set from the transport agency to validate our model for the level of accuracy in predicted bus arrival time and scheduled arrival time to disseminate data using bus services. Data were uploaded onto buses as per their dwelling time at each stop and terminals within the coverage area of deployed RSU. The offloading capacity of our proposed data dissemination system showed that it could be utilized to effectively complement traditional data networks. Moreover, the maximum offloading capacity at each parent stop could reach up to 360 GB with a huge saving of energy consumption.
Rashmi Munjal; William Liu; Xue Li; Jairo Gutierrez. A Neural Network-Based Sustainable Data Dissemination through Public Transportation for Smart Cities. Sustainability 2020, 12, 10327 .
AMA StyleRashmi Munjal, William Liu, Xue Li, Jairo Gutierrez. A Neural Network-Based Sustainable Data Dissemination through Public Transportation for Smart Cities. Sustainability. 2020; 12 (24):10327.
Chicago/Turabian StyleRashmi Munjal; William Liu; Xue Li; Jairo Gutierrez. 2020. "A Neural Network-Based Sustainable Data Dissemination through Public Transportation for Smart Cities." Sustainability 12, no. 24: 10327.
This paper presents a compact frequency reconfigurable antenna for flexible devices and conformal surfaces. The antenna consists of a simple easy to fabricate structure consisting of a stub loaded circular radiator, designed on commercially available RT5880 flexible substrate (εr = 2.2) with a thickness of 0.254 mm. The combination of stub loading and slot etching techniques are utilized to achieve the advantages of compactness, frequency reconfigurability, wide impedance bandwidth, and stable radiation pattern with structural conformability. The frequency reconfigurability is achieved by employing two p-i-n diodes. Simulated and experimental results showed that the antenna operates in various important commercial bands, such as S-band (2 GHz– 4 GHz), Wi-Max (3.5 GHz and 5.8 GHz), Wi-Fi (3.6 GHz, 5 GHz, and 5.9 GHz), 5G sub-6-GHz (3.5 GHz and 4.4 GHz – 5 GHz), and ITU-band (7.725 GHz – 8.5 GHz) with the additional advantages of structural conformability. Furthermore, the performance comparison of the proposed flexible antenna with the state-of-the-art flexible antennas in terms of compactness, frequency reconfigurability, and number of operating bands demonstrates the novelty of the proposed antenna and its potential application in heterogeneous applications.
Niamat Hussain; Wahaj Abbas Awan; Syeda Iffat Naqvi; Adnan Ghaffar; Abir Zaidi; Adnan Iftikhar; Xue Jun Li. A Compact Flexible Frequency Reconfigurable Antenna for Heterogeneous Applications. IEEE Access 2020, 8, 173298 -173307.
AMA StyleNiamat Hussain, Wahaj Abbas Awan, Syeda Iffat Naqvi, Adnan Ghaffar, Abir Zaidi, Adnan Iftikhar, Xue Jun Li. A Compact Flexible Frequency Reconfigurable Antenna for Heterogeneous Applications. IEEE Access. 2020; 8 (99):173298-173307.
Chicago/Turabian StyleNiamat Hussain; Wahaj Abbas Awan; Syeda Iffat Naqvi; Adnan Ghaffar; Abir Zaidi; Adnan Iftikhar; Xue Jun Li. 2020. "A Compact Flexible Frequency Reconfigurable Antenna for Heterogeneous Applications." IEEE Access 8, no. 99: 173298-173307.
This article presents a novel flexible wideband ink-printed dipole array antenna for emerging medical sensing and human body wearable electronics applications. The antenna operates from 23 GHz to 30 GHz, including 24.5 GHz and 28 GHz for 5G application. The antenna consists of simple layered screen printed structure, which is suitable for rapid prototyping with printing technology. Both simulation and measurement results are presented, which shows a percentage bandwidth of 26.4% and a maximum forward gain of 4.2 dBi. Further investigations are conducted to analyse the effects of imperfect fabrication process on the antenna performance.
Erfeng Li; Xue Jun Li; Boon-Chong Seet; XiaoYou Lin. Ink-printed flexible wideband dipole array antenna for 5G applications. Physical Communication 2020, 43, 101193 .
AMA StyleErfeng Li, Xue Jun Li, Boon-Chong Seet, XiaoYou Lin. Ink-printed flexible wideband dipole array antenna for 5G applications. Physical Communication. 2020; 43 ():101193.
Chicago/Turabian StyleErfeng Li; Xue Jun Li; Boon-Chong Seet; XiaoYou Lin. 2020. "Ink-printed flexible wideband dipole array antenna for 5G applications." Physical Communication 43, no. : 101193.
This Letter presents the design and analysis of a tunable low noise amplifier (LNA) capable of achieving single band, dual band and wideband operations. The circuit features a modified tunable open stub matching to achieve a reconfigurable multiband response. The LNA adopts a varactor diode in the input matching stage to achieve reconfigurable modes. Two bias conditions for the varactor diode are analysed. The forward bias condition yields a wideband mode (1.6 to 2.5 GHz) and zero bias results in a concurrent dual band mode (0.9 and 1.7–2.5 GHz). In reverse bias condition, the bias voltage of varactor diode () can be tuned to achieve one single band mode (1 GHz), and a tunable concurrent dual band mode, where the first band is fixed at 1 GHz and the second band is continuously tunable from 1.7 to 2.5 GHz. The LNA is fabricated in microwave integrated circuit process on an FR-4 board. The measured power gain is 7–15 dB and noise figure is 1.2–2.2 dB across all bands. The measured 1 dB compression () is , and at 0.9, 1 and 2.4 GHz, respectively.
A. Aneja; X. J. Li. Design of a multimode tunable low noise amplifier for software defined radios. Electronics Letters 2020, 56, 808 -810.
AMA StyleA. Aneja, X. J. Li. Design of a multimode tunable low noise amplifier for software defined radios. Electronics Letters. 2020; 56 (16):808-810.
Chicago/Turabian StyleA. Aneja; X. J. Li. 2020. "Design of a multimode tunable low noise amplifier for software defined radios." Electronics Letters 56, no. 16: 808-810.
Investigating and classifying sentiments of social media users (e.g., positive, negative) towards an item, situation, and system are very popular among the researchers. However, they rarely discuss the underlying socioeconomic factor associations for such sentiments. This study attempts to explore the factors associated with positive and negative sentiments of the people about reopening the economy, in the United States (US) amidst the COVID-19 global crisis. It takes into consideration the situational uncertainties (i.e., changes in work and travel pattern due to lockdown policies), economic downturn and associated trauma, and emotional factors such as depression. To understand the sentiment of the people about the reopening economy, Twitter data was collected, representing the 51 states including Washington DC of the US. State-wide socioeconomic characteristics of the people (e.g., education, income, family size, and employment status), built environment data (e.g., population density), and the number of COVID-19 related cases were collected and integrated with Twitter data to perform the analysis. A binary logit model was used to identify the factors that influence people toward a positive or negative sentiment. The results from the logit model demonstrate that family households, people with low education levels, people in the labor force, low-income people, and people with higher house rent are more interested in reopening the economy. In contrast, households with a high number of members and high income are less interested to reopen the economy. The accuracy of the model is good (i.e., the model can correctly classify 56.18\% of the sentiments). The Pearson chi2 test indicates that overall this model has high goodness-of-fit. This study provides a clear indication to the policymakers where to allocate resources and what policy options they can undertake to improve the socioeconomic situations of the people and mitigate the impacts of pandemics in the current situation and as well as in the future.
Mokhlesur Rahman; G. G. Md. Nawaz Ali; Xue Jun Li; Kamal Chandra Paul; Peter H.J. Chong. Twitter and Census Data Analytics to Explore Socioeconomic Factors for Post-COVID-19 Reopening Sentiment. 2020, 1 .
AMA StyleMokhlesur Rahman, G. G. Md. Nawaz Ali, Xue Jun Li, Kamal Chandra Paul, Peter H.J. Chong. Twitter and Census Data Analytics to Explore Socioeconomic Factors for Post-COVID-19 Reopening Sentiment. . 2020; ():1.
Chicago/Turabian StyleMokhlesur Rahman; G. G. Md. Nawaz Ali; Xue Jun Li; Kamal Chandra Paul; Peter H.J. Chong. 2020. "Twitter and Census Data Analytics to Explore Socioeconomic Factors for Post-COVID-19 Reopening Sentiment." , no. : 1.
Investigating and classifying sentiments of social media users (e.g., positive, negative) towards an item, situation, and system are very popular among the researchers. However, they rarely discuss the underlying socioeconomic factor associations for such sentiments. This study attempts to explore the factors associated with positive and negative sentiments of the people about reopening the economy, in the United States (US) amidst the COVID-19 global crisis. It takes into consideration the situational uncertainties (i.e., changes in work and travel pattern due to lockdown policies), economic downturn and associated trauma, and emotional factors such as depression. To understand the sentiment of the people about the reopening economy, Twitter data was collected, representing the 51 states including Washington DC of the US. State-wide socioeconomic characteristics of the people (e.g., education, income, family size, and employment status), built environment data (e.g., population density), and the number of COVID-19 related cases were collected and integrated with Twitter data to perform the analysis. A binary logit model was used to identify the factors that influence people toward a positive or negative sentiment. The results from the logit model demonstrate that family households, people with low education levels, people in the labor force, low-income people, and people with higher house rent are more interested in reopening the economy. In contrast, households with a high number of members and high income are less interested to reopen the economy. The accuracy of the model is good (i.e., the model can correctly classify 56.18% of the sentiments). The Pearson chi2 test indicates that overall this model has high goodness-of-fit. This study provides a clear indication to the policymakers where to allocate resources and what policy options they can undertake to improve the socioeconomic situations of the people and mitigate the impacts of pandemics in the current situation and as well as in the future.
Mokhlesur Rahman; G. G. Md. Nawaz Ali; Xue Jun Li; Kamal Chandra Paul; Peter H.J. Chong. Twitter and Census Data Analytics to Explore Socioeconomic Factors for Post-COVID-19 Reopening Sentiment. 2020, 1 .
AMA StyleMokhlesur Rahman, G. G. Md. Nawaz Ali, Xue Jun Li, Kamal Chandra Paul, Peter H.J. Chong. Twitter and Census Data Analytics to Explore Socioeconomic Factors for Post-COVID-19 Reopening Sentiment. . 2020; ():1.
Chicago/Turabian StyleMokhlesur Rahman; G. G. Md. Nawaz Ali; Xue Jun Li; Kamal Chandra Paul; Peter H.J. Chong. 2020. "Twitter and Census Data Analytics to Explore Socioeconomic Factors for Post-COVID-19 Reopening Sentiment." , no. : 1.
In this paper, we proposed a new wireless localization technique based on the ideology of social network analysis (SNA), to study the different properties of networks as a graph. Centrality is a main concept in SNA, so we propose using closeness centrality (CC) as a measurement to denote the importance of the node inside the network due to its geo-location to others. The node with highest degree of CC is chosen as a cluster heads, then each cluster head can form its trilateration process to collect data from its cluster. The selection of closest cluster based on CC values, and the unknown node’s location can be estimated through the trilateration process. To form a perfect trilateration, the cluster head chooses three anchor nodes. The proposed algorithm provides high accuracy even in different network topologies like concave shape, O shape, and C shape as compared to existing received signal strength indicator (RSSI) techniques. Matlab simulation results based on practical radio propagation data sets showed a localization error of 0.32 m with standard deviation of 0.26 m.
Tanveer Ahmad; Xue Jun Li; Boon-Chong Seet; Juan-Carlos Cano. Social Network Analysis Based Localization Technique with Clustered Closeness Centrality for 3D Wireless Sensor Networks. Electronics 2020, 9, 738 .
AMA StyleTanveer Ahmad, Xue Jun Li, Boon-Chong Seet, Juan-Carlos Cano. Social Network Analysis Based Localization Technique with Clustered Closeness Centrality for 3D Wireless Sensor Networks. Electronics. 2020; 9 (5):738.
Chicago/Turabian StyleTanveer Ahmad; Xue Jun Li; Boon-Chong Seet; Juan-Carlos Cano. 2020. "Social Network Analysis Based Localization Technique with Clustered Closeness Centrality for 3D Wireless Sensor Networks." Electronics 9, no. 5: 738.
This letter proposes a novel downlink hybrid multiple access (HMA) scheme based on non-orthogonal multiple access (NOMA) and orthogonal multiple access (OMA) for the fifth generation (5G) networks. A necessary condition on the users' channel gains under which HMA can outperform pure NOMA or OMA is derived. Furthermore, an optimization problem is formulated and solved numerically to obtain optimal groups size resulting in optimal throughput. The exact closed-form expression for the outage probability is also derived. Numerical results are presented to compare the average outage and throughput performance of HMA with conventional NOMA and OMA. In addition, the impact of varying OMA group size on throughput is also presented.
Asim Anwar; Boon-Chong Seet; Xuejun Li. Hybrid multiple access for 5G downlink systems: Throughput and outage analysis. AEU - International Journal of Electronics and Communications 2020, 117, 153100 .
AMA StyleAsim Anwar, Boon-Chong Seet, Xuejun Li. Hybrid multiple access for 5G downlink systems: Throughput and outage analysis. AEU - International Journal of Electronics and Communications. 2020; 117 ():153100.
Chicago/Turabian StyleAsim Anwar; Boon-Chong Seet; Xuejun Li. 2020. "Hybrid multiple access for 5G downlink systems: Throughput and outage analysis." AEU - International Journal of Electronics and Communications 117, no. : 153100.
At present, the ultrahigh frequency (UHF) radio-frequency identification (RFID) technology is more popular than several other autoidentification (auto-ID) technologies. An ultrarugged UHF RFID reader antenna is made from a concrete substrate that is sandwiched between a stubbed quarterwave radiator and a folded ground plane is proposed for fixed UHF RFID readers. This linearly polarized antenna operates between 865 and 868 MHz with a 3.5-dBi peak gain and a 160-MHz, -15-dB |S11| bandwidth. The 3.5- and 2-dBi gain bandwidth are 80 and 140 MHz, respectively. The antenna is intended to be used in convention center loading docks and is thus tested for extreme environmental conditions, such as temperature, humidity, condensation, and rain as well as the effect of superstrates and metals. More than one concrete tile antenna can be operated by using one RFID reader to realize a distributed antenna system (DAS). The antenna is conformal and can blend with the environment without affecting the existing aesthetics. The antenna creates a wide circumferential read zone (∼5.6-m diameter) and reads tags up to 6.5 m at the boresight in free space.
Prabakar Parthiban; Boon-Chong Seet; Xue Jun Li. An Ultra-Rugged UHF RFID Reader Antenna: A New Design for Convention Center Loading Docks [Wireless Corner]. IEEE Antennas and Propagation Magazine 2020, 62, 84 -95.
AMA StylePrabakar Parthiban, Boon-Chong Seet, Xue Jun Li. An Ultra-Rugged UHF RFID Reader Antenna: A New Design for Convention Center Loading Docks [Wireless Corner]. IEEE Antennas and Propagation Magazine. 2020; 62 (1):84-95.
Chicago/Turabian StylePrabakar Parthiban; Boon-Chong Seet; Xue Jun Li. 2020. "An Ultra-Rugged UHF RFID Reader Antenna: A New Design for Convention Center Loading Docks [Wireless Corner]." IEEE Antennas and Propagation Magazine 62, no. 1: 84-95.
The flourish of mobile communications is driven by the increasing number of subscribers and rapid advance of electronic devices. This brings up many multimedia context-aware services, among which real time locating system (RTLS) has become necessary in many applications. To locate a mobile station (MS), RTLS could apply conventional fingerprinting algorithm using received signal strength indicator (RSSI), which allows a MS to collect RSSI data from beacons sent by access points (APs). However, this method does not work for iPhones because of the lack of open access to Apple application programming interface (API) to obtain RSSI values. This paper proposes an alternative approach, under which APs in the monitoring mode are used to collect RSSI values for semi-beacon packets sent from a MS. We implement the packet capture library, which enables us to obtain RSSI values of semi-beacon packets sent by an iPhone. With a region-based k-nearest neighbor (kNN) localization algorithm, we successfully locate an iPhone user in indoor environment. In addition, experimental results show that the proposed approach outperforms the conventional RSSI fingerprinting approach.
Xue Jun Li; M. Bharanidharan. RSSI Fingerprinting Based iPhone Indoor Localization System Without Apple API. Wireless Personal Communications 2019, 112, 61 -74.
AMA StyleXue Jun Li, M. Bharanidharan. RSSI Fingerprinting Based iPhone Indoor Localization System Without Apple API. Wireless Personal Communications. 2019; 112 (1):61-74.
Chicago/Turabian StyleXue Jun Li; M. Bharanidharan. 2019. "RSSI Fingerprinting Based iPhone Indoor Localization System Without Apple API." Wireless Personal Communications 112, no. 1: 61-74.
The fifth generation (5G) wireless systems are anticipated to meet unprecedented capacity and latency requirements. In order to resolve these challenges in 5G, non-orthogonal multiple access (NOMA) is considered as a promising technique due to its ability to enhance spectrum efficiency and user access. As opposed to conventional orthogonal multiple access (OMA) which relies on orthogonal resource sharing, NOMA has a potential of supporting a higher number of users by multiplexing different users in the same resource in a non-orthogonal manner. With advanced receiver techniques, such as successive interference cancellation (SIC), the intra-user interference can be minimized at the NOMA receiver. To date, there are comprehensive surveys on NOMA, which describe the integration of NOMA with different communication technologies and discuss different NOMA classifications. However, the existing literature is scarce in reviewing state-of-the-art applications of NOMA from the perspective of its application to cellular networks (CNs), device-to-device (D2D) communications, and wireless sensor networks (WSNs). Therefore, the purpose of this survey is to fill this gap in knowledge. Specifically, NOMA with its underlying concepts are elaborated in detail. In addition, detailed system model of different NOMA-based wireless networks is presented. Furthermore, irrespective of the underlying spatial topology of the considered NOMA-based wireless network, general analytical expressions are presented to characterize the network performance. Finally, some challenges related to NOMA design are highlighted and potential research directions are pointed out to address these issues.
Asim Anwar; Boon-Chong Seet; Muhammad Amish Hasan; Xue Jun Li. A Survey on Application of Non-Orthogonal Multiple Access to Different Wireless Networks. Electronics 2019, 8, 1355 .
AMA StyleAsim Anwar, Boon-Chong Seet, Muhammad Amish Hasan, Xue Jun Li. A Survey on Application of Non-Orthogonal Multiple Access to Different Wireless Networks. Electronics. 2019; 8 (11):1355.
Chicago/Turabian StyleAsim Anwar; Boon-Chong Seet; Muhammad Amish Hasan; Xue Jun Li. 2019. "A Survey on Application of Non-Orthogonal Multiple Access to Different Wireless Networks." Electronics 8, no. 11: 1355.
Smart cities require interactive management of water supply networks and water meters play an important role in such a task. As compared to fully mechanical water meters, electromechanical water meters or fully electronic water meters can collect real-time information through automatic meter reading (AMR), which makes them more suitable for smart cities applications. In this paper, we first study the design principles of existing water meters, and then present our design and implementation of a self-powered smart water meter. The proposed water meter is based on a water turbine generator, which serves for two purposes: (i) to sense the water flow through adaptive signal processing performed on the generated voltage; and (ii) to produce electricity to charge batteries for the smart meter to function properly. In particular, we present the design considerations and implementation details. The wireless transceiver is integrated in the proposed water meter so that it can provide real-time water flow information. In addition, a mobile phone application is designed to provide a user with a convenient tool for water usage monitoring.
Xue Jun Li; Peter Han Joo Chong. Design and Implementation of a Self-Powered Smart Water Meter. Sensors 2019, 19, 4177 .
AMA StyleXue Jun Li, Peter Han Joo Chong. Design and Implementation of a Self-Powered Smart Water Meter. Sensors. 2019; 19 (19):4177.
Chicago/Turabian StyleXue Jun Li; Peter Han Joo Chong. 2019. "Design and Implementation of a Self-Powered Smart Water Meter." Sensors 19, no. 19: 4177.
Thanks to IEEE 802.15.4 defining the operation of low-rate wireless personal area networks (LR-WPANs), the door is open for localizing sensor nodes using tiny, low power digital radios such as Zigbee. In this paper, we propose a three-dimensional (3D) localization scheme based on well-known loop invariant for division algorithm. Parametric points are proposed by using the reference anchor points bounded in an outer region named as Parametric Loop Division (PLD) algorithm. Similar to other range-based localization methods, PLD is often influenced by measurement noise which greatly degrades the performance of PLD algorithm. We propose to adopt extended Kalman filtering (EKF) to refine node coordinates to mitigate the measurement noise. We provide an analytical framework for the proposed scheme and find the lower bound for its localization accuracy. Simulation results show that compared with the existing PLD algorithm, our technique always achieves better positioning accuracy regardless of network topology, communication radius, noise statistics, and the node degree of the network. The proposed scheme PLD-EKF provides an average localization accuracy of 0.42 m with a standard deviation of 0.26 m.
Tanveer Ahmad; Xue Jun Li; Boon-Chong Seet. Noise Reduction Scheme for Parametric Loop Division 3D Wireless Localization Algorithm Based on Extended Kalman Filtering. Journal of Sensor and Actuator Networks 2019, 8, 24 .
AMA StyleTanveer Ahmad, Xue Jun Li, Boon-Chong Seet. Noise Reduction Scheme for Parametric Loop Division 3D Wireless Localization Algorithm Based on Extended Kalman Filtering. Journal of Sensor and Actuator Networks. 2019; 8 (2):24.
Chicago/Turabian StyleTanveer Ahmad; Xue Jun Li; Boon-Chong Seet. 2019. "Noise Reduction Scheme for Parametric Loop Division 3D Wireless Localization Algorithm Based on Extended Kalman Filtering." Journal of Sensor and Actuator Networks 8, no. 2: 24.