Mobile Terminal Applications Research Articles

A multimode substrate integrated waveguide based s elf‐hexplexing antenna for mobile terminal applications

A low-profile self-hexplexing antenna based on the multimode substrate integrated waveguide (SIW) cavity is presented for mobile terminal applications. It has three feeding ports, each of which can generate two resonant modes. Taking the advantage of the truncated SIW resonant cavity, the footprint of the antenna remains compact in the multiple functional mode scenario. The proposed antenna operates at six different modes, namely TM10 mode at 3.55 GHz, TM01 mode at 4.85 GHz, TE110 mode at 2.45 GHz, TE220 mode at 5.6 GHz, TE110 mode at 3.4 GHz and TE120 mode at 5.35 GHz. Good agreement is achieved between the simulated and measured antenna performance. The excitation and field distribution of each mode is analyzed. Keeping the structure miniaturized, the proposed antenna realizes hex-band characteristics without excessive feeding ports. It can be used for Microwave Access (WIMAX), the 5th Generation Mobile Communication Technology (5G) and Wireless Local Area Network (WLAN) applications, which is suitable for mobile handheld multiband terminals.

Planarized quasi‐self‐complementary antenna design with ground‐cooperative radiating for mobile terminal applications

This paper presents a multiband antenna implemented on mobile terminals' simple and planar quasi-self-complementary (QSC) structure. A wideband antenna is initially developed by employing a triangular patch, and its complementary triangular slot etched on the ground. Then the ground-cooperative radiating method is combined with the QSC structure. This combination helps to introduce more resonant current paths without increasing the footprint, resulting in additional coverage of lower and higher working bands. The design scheme is validated by both simulation and measurement. Measured results indicate that the proposed antenna provides three separate impedance bandwidths of 310 MHz (0.69–1 GHz), 1070 MHz (1.71–2.78 GHz), and 800 MHz (3–3.8 GHz), covering the desired 5G/LTE/WWAN operations. Meanwhile, moderate antenna efficiencies are obtained across the operating bands. The QSC structure ensures stable frequency responses and acceptable radiation properties for handheld applications. The antenna could be a promising candidate in practical wireless communications due to its desirable performance and slim configuration.

Agnostic Envelope Linearization of Dynamically Supplied Power Amplifiers for Mobile Terminals.

This paper presents an envelope linearization technique to compensate for the nonlinear distortion of envelope tracking (ET) power amplifiers (PAs) for 5G new radio (NR) mobile terminals. The proposed envelope optimization (EOPT) method is agnostic of the nonlinear distortion generated in the envelope supply path and can compensate for the nonlinear distortion at the ET PA output without the need to monitor the output at the envelope tracking modulator (ETM). The linearization system in the envelope path is based on the envelope generalized memory polynomial (EGMP) behavioral model. Since the ETM output is not available, an iterative nonlinear least squares solution inspired in the deep deterministic policy gradient (DDPG) algorithm is proposed to extract the coefficients of the EGMP model. The EOPT method is validated on a system-on-chip (SoC) ET PA board designed for mobile terminal applications. Experimental results show the suitability of the proposed method to guarantee the linearity requirements (i.e., adjacent channel power ratio below −36 dBc) with 16.8% of power efficiency when operating the ET PA with 5G new radio test signals of 60 MHz bandwidth operating at 2.55 GHz (band 7). The linearization performance of the proposed EOPT method is comparable to the envelope leakage cancellation (ELC) approach (but saving the need for an analog to digital converter to monitor the ETM output), and can outperform a conventional I-Q digital predistorter based on the generalized memory polynomial (GMP) behavioral model.

A scanning beam antenna fed by a 7 × 8 Butler matrix for 5G applications

A 7 × 8 Butler matrix (BM) beam-forming network operating at Ka-band is proposed to feed a 8 × 8 slot array. By merging the two central input ports of the BM into one port, the BM can provide output signals with equal phase, thereby generating a boresight beam. Measured results show that the proposed antenna has impedance bandwidth of 29.5–30.5 GHz, while the gain lies in the range of 14.7–21.8 dBi. Seven beams are realized, including a boresight beam, covering the range from −58° to 58°. In order to verify this concept, the feeding network and antenna are designed and manufactured. The measured results are in good agreement with simulation. It is a capable candidate for 5G mobile terminal applications.

Compact Dual-Polarized Eight-Element Antenna with High Isolation for 5 G Mobile Terminal Applications

Compact Dual-Polarized Eight-Element Antenna with High Isolation for 5 G Mobile Terminal Applications

Co‐design of Sub‐6 GHz and mm‐wave array antennas with metal frame for 5G mobile terminals

AbstractIn this letter, a compact antenna module working at Sub‐6 GHz and millimeter‐wave (mm‐wave) bands is presented for 5G mobile terminal applications. The module includes a long slot etched at the edge of the chassis ground and four short slots etched on the metal frame. By placing the two kinds of slots together, the short slots can work at the quarter‐wavelength mode, thus the length of the short slots on the metal frame is merely 1.4 mm. It greatly reduces the risk of signal attenuation by users' touch. Experimental results show that the proposed design can provide MIMO function at 3.5 GHz band, and wide‐angle beam steering function at 28 GHz band.

Analysis on the New Ways of International Trade Cross Border E-Commerce Research from Big Data Theory

With the popularity of the Internet, the server terminal will receive massive data every day. Therefore, China has entered the era of big data. Mobile terminal applications have subverted people’s traditional user experience, which has brought significant changes in business model. Therefore, big data has become an important strategic resource, which has become an important means of technological innovation used by enterprises. Through big data mining and other technologies, enterprises can analyze the global price changes in international trade (hereinafter referred to as ITT). By analyzing user behavior, enterprises can push appropriate products to users. Therefore, big data technology has been applied to ITT, especially Cross Border E-Commerce (hereinafter referred to as CBEC). Therefore, this paper first analyzes the application process of big data technology to CBEC. Then, this paper puts forward the future business model. Finally, some suggestions are put forward.

Wideband Decoupled 8-Element MIMO Antenna for 5G Mobile Terminal Applications

A wideband decoupled dual-antenna pair is proposed and designed for 5G mobile terminal applications, with the help of characteristic mode theory. Parasitic strip and defective ground structure are used simultaneously to realize broadband and high isolation. Based on the proposed decoupled antenna pair, an eight-element multiple-input--multiple-output (MIMO) antenna is presented by placing four pairs at both side frames. By etching slits on the system ground, the mutual coupling between antenna pairs is effectively reduced. A prototype of the proposed antenna array is successfully fabricated and measured. Both simulated and experimental results indicate that the proposed eight-element MIMO antenna can completely cover n77/n78/n79 bands of the 5G New Radio and wireless local area network 5 GHz band. Furthermore, an isolation better than 15 dB is achieved between any two ports.

Multiple input multiple output (MIMO) and fifth generation (5G): an indispensable technology for sub-6 GHz and millimeter wave future generation mobile terminal applications

AbstractThe in-depth exploration in the future 5G technology symbolizes a revolution in technology for antenna designers to encounter the all time increasing need as well as demand for higher data rate wireless communications. The paper gives out an exhaustive review of the evolution and characteristics of the 5G spectrum allocations, the MIMO antenna design with regard to mutual coupling reduction techniques and safer user applications. It precisely covers almost all the aspects of 5G which mainly include the types of antenna designs and their performance parameters related to MIMO design. The paper also presents a brief description of massive MIMO technology for base station applications. The main aim of the paper is: (1) to emphasize the frequencies allocated for the 5G including sub-6 Ghz and mm-wave bands; (2) to underline the suitable antenna designs for MIMO applications for mobile devices and base stations; (3) to highlight the mutual coupling effects in MIMO designs and its reduction techniques; (4) to consider the gaps in the literature and the challenges for reducing SAR effects for the safety of the users. This review paper has been an attempt to explore the evolution of 5G bands and antenna designs for 5G applications, comparison based on the literature, and the techniques implemented for enhancing the MIMO antenna performances.

Spruce Counting Based on Lightweight Mask R-CNN with UAV Images

To achieve rapid and accurate counting of seedlings on mobile terminals such as Unmanned Aerial Vehicle (UAV), we propose a lightweight spruce counting model. Given the difficulties of spruce adhesion and complex environment interference, we adopt the Mask R-CNN as the basic model, which performs instance-level segmentation of the target. To successfully apply the basic model to the mobile terminal applications, we modify the Mask R-CNN model in terms of the light-weighted as follows: the feature extraction network is changed to MobileNetV1 network; NMS is changed to Fast NMS. At the implementation level, we expand the 403 spruce images taken by UAV to the 1612 images, where 1440 images are selected as the training set and 172 images are selected as the test set. We evaluate the lightweight Mask R-CNN model. Experimental results indicate that the Mean Counting Accuracy (MCA) is 95%, the Mean Absolute Error (MAE) is 8.02, the Mean Square Error (MSE) is 181.55, the Average Counting Time (ACT) is 1.514 s, and the Model Size (MS) is 90Mb. We compare the lightweight Mask R-CNN model with the counting effects of the Mask R-CNN model, the SSD+MobileNetV1 counting model, the FCN+Hough circle counting model, and the FCN+Slice counting model. ACT of the lightweight Mask R-CNN model is 0.876 s, 0.359 s, 1.691 s, and 2.443 s faster than the other four models, respectively. In terms of MCA, the lightweight Mask R-CNN model is similar to the Mask R-CNN model. It is 4.2%, 5.2%, and 9.3% higher than the SSD+MobileNetV1 counting model, the FCN+Slice counting model, and the FCN+Hough circle counting model, respectively. Experimental results demonstrate that the lightweight Mask R-CNN model achieves high accuracy and real-time performance, and makes a valuable exploration for the deployment of automatic seedling counting on the mobile terminal.

Dual Monopole Frequency Reconfigurable Antenna for MIMO 5G sub-6 GHz Mobile Terminal

In this paper, a Dual Monopole Frequency Reconfigurable Antenna (DMFRA) for two port Multiple Input Multiple Output (MIMO) Fifth Generation (5G) sub-6 GHz mobile terminal is presented. A combination of dual monopole strips is implemented at a port, respectively to achieve tunable and fixed resonant frequencies. Varactor diode is utilized in this design to perform the frequency reconfiguration. Dual tunable resonant frequencies at the lower band (1690 MHz to 2200 MHz) and higher band (4400 MHz to 5400 MHz) are created by the monopole branch which accommodates the varactor diode. On the other hand, a fixed frequency band at 2400 MHz with -10 dB bandwidth of 450 MHz is achieved by another monopole branch without variable diode. Maximum realized gain achieved at both lower and higher reconfigurable frequency bands and fixed frequency band are 2.73 dB, 3.8 dB and 2.57 dB, respectively. Besides that, high isolation between 2 DMFRAs decreases the mutual coupling to result in less than 0.1 of the Envelope Correlation Coefficient (ECC). In addition to its frequency reconfiguration capability and low ECC, the proposed MIMO antenna is considered suitable for potential 5G mobile terminal applications.

Design and Analysis of MIMO Dual Band Patch Antenna for 5G New Radio Applications in Mobile Terminals

This paper presents a dual-band MIMO antenna design with compact size for 5G communication under 6 GHz band frequency. The metallic monopole stub structure is used to miniaturization of antenna. The L-shape monopole antenna is modified by adding semi-circular element in radiating structure of monopole to obtain dual-band resonance. The High isolation is achieved by employing T-shaped stub in ground plane.It has compact size is 45 mm × 25 mm × 1.6 mm3. The proposed Dual Band MIMO antenna has been design on FR4 material with ɛr = 4.4 with 1.6 thickness. The proposed antenna has 5G application in the bands of 2.5 GHz (2.34 GHz-2.62 GHz) and 3.5 GHz (3.20 GHz-5.20 GHz). The bandwidth of antenna getting 320MHz and 2500MHz at 2.5GHz and 3.5GHz respectively. The Isolation (S21) of proposed antenna is -31.2 dB at 2.5 GHz and -19.5 dB at 3.5 GHz. VSWR is less than 1.06 for both the bands. The designed dual band MIMO antenna covers 5G bands of 2.3-2.4GHz (n30/n40), 2.4-2.5GHz (n7/n38/n41/n90), and 3.2-5.2GHz (n77/n78/n80). The experimental and simulated results observed good matching except some slight variation. This proposed dual band MIMO antenna is suitable for 5G mobile Communications.

Joint Computation Offloading and Data Caching Based on Cooperation of Mobile-Edge-Computing-Enabled Base Stations

Mobile terminal applications with high computing complexity and high time delay sensitivity are developing quite fast today, which aggravates the load of mobile cloud computing and storage and further leads to network congestion and service quality decline. Mobile edge computing (MEC) is a way of breaking through the limits of computing and storage resources of mobile cloud and alleviating the load of mobile cloud. Computing time costs and transmission time costs are considered to be the main issues for the mobile cloud when carrying out computing offloading and data caching. Therefore, an efficient resource management strategy, which could minimize the system delay, is proposed in this paper. The new scheme offloads reasonably computing tasks and caches the tasks’ data from the mobile cloud to mobile edge computing-enabled base stations. An intelligence algorithm, genetic algorithm, is being used to solve the global optimization problem which would cause transmission delay and computing resources occupation, and to determine the computing offloading and data caching probability. The simulation of the system using MATLAB is conducted in 8 different scenarios with different parameters. The results show that our new scheme improves the system computing speed and optimizes the user experience in all scenarios, compared with the scheme without data caching and the scheme without computing offloading and data caching.

Research on fine management of expressway construction schedule, quality and safety based on mobile terminal

In view of the management characteristics of highway engineering, it integrates BIM, mobile Internet, cloud computing, Internet of things and other technologies to study and establish a fine and collaborative management platform for project progress, quality and safety on the basis of mobile terminal application. This paper realize the dynamic control of project construction resources with progress as the main line and the collaborative management of projects with safety and quality as the core. It can meet the application analysis demands of all parties involved in the construction of highway for the whole service data, and give full play to the convenience of mobile terminals, and carry out task coordination and mobile operation of various management work in time through the mobile terminal anytime and anywhere. At the same time, the data of the mobile terminal is associated with the structure through BIM model, which can be statistically analyzed and visually displayed, and realize the collaborative association of various business data, thus greatly improving the refined management level of highway engineering construction.

An efficient tunable decoupling and matching method for simplifying compact dual‐band mobile terminal antennas

An efficient tunable decoupling and matching method is proposed for simplifying compact mobile terminal antennas, that operates simultaneously in two independent bands. To enable carrier aggregation, the lower band in this design is tunable over the frequencies of interest for the traditional standards, while the upper band provides a fixed broad bandwidth to meet the bandwidth demands of 5G mobile terminal applications. Multi-element antenna systems, containing a simple antenna structure combined with tunable networks to realize dual-band decoupling and matching function, are systematically studied. The network structures are simplified to minimize the losses incurred in maintaining a good performance. To demonstrate the proposed approach, a two-element antenna system is developed in which the lower band can be tuned over the frequency range of 2.25 to 2.75 GHz, and the broad upper band can cover frequencies from 4.42 to 6.21 GHz. Good performance such as high total efficiency, low envelope correlation coefficient and stable radiation patterns, can be observed, thus, validating the effectiveness of the proposed method for simplifying the antenna structure.

The Application of Computer Technology in China Art Education

The application of computer technology in the field of education can bring about great changes, not only the application of computer as a tool, but also includes the development of network technology based on computer technology, mobile phone terminal application technology, and use network technology as a supporting structure, to promote the invention and use of online teaching platform and a variety of mobile education software. According to their purpose and function designed, they can be classified to three parts, it will be the systems to manage teaching progress, learning activities, communicate platform and results database. Application of computer technology in art education has experienced the "Internet popularity - start layout - application platform - -smart campus" overall construction stage, showing a new look of "Internet + art education" in China. Compared with traditional educational means, they all make Chinese art education more vivid, cordial and interactive, although there are still many problems in the application of computer technology to art education, in the future of 5G technology mature, big data and digital technology, there will be more new computer technologies and new computer technology achievements applied to art education, will bring more promotion and possibilities to the education industry.

Dual circular slot ring triple-band MIMO antenna for 5G applications

Abstract A Triple-band Multiple-Input-Multiple-Output (MIMO) antenna for 5G mobile terminal applications is proposed in this paper. The design comprises four-port/two resonators, each having two concentric circular slot ring radiators etched on a ground plane of size 50 mm × ${\times}$ 50 mm. The antenna is fed by perpendicularly arranged 50 Ω microstrip line feeds on the top layer. Decoupling techniques were used to suppress mutual coupling between the two resonators. The perpendicular arrangement of the feed lines and port reduces mutual coupling between the two ports and increases isolation. The antenna operates in multiple bands: 3.35–3.69 GHz, 24–28 GHz, and 37–40 GHz frequency range with central frequencies at 3.5 GHz, 26 GHz, and 38 GHz, respectively allocated for 5G. The antenna provides a gain of 2.7–7.8 dB and a radiation efficiency of 0.49–0.85 in the operating bands. Diversity performance is studied in terms of the Envelop Correlation Coefficient (ECC), Diversity Gain (DG), and Total Active Reflection Coefficient (TARC) were found to be less than 0.01, greater than 9.99 dB, and less than −10 dB respectively. The proposed antenna offers good S-parameters, voltage standing wave ratio (VSWR), TARC, radiation pattern, high gain, and low ECC. The antenna was fabricated and tested. The measured results and simulated results are in good agreement. It possesses sufficient potential for 5G mobile terminal and smart wearable applications.

Design of MIMO antenna system operating in wideband of 3300 to 6400 MHz for future 5G mobile terminal applications

In this paper, a wideband eight‐element antenna array operating in the 5G (Fifth‐generation) NR (New Radio) frequency bands N77/N78/N79 (3300‐5000 MHz), LTE (Long Term Evolution) band 46 (5150‐5925 MHz), and EU (European Union) 5G band of 5900 to 6400 MHz for 8 × 8 MIMO (Multi‐Input Multi‐Output) operation in the future 5G mobile terminal is presented. The proposed eight antenna elements are all co‐coupled‐fed IFA (Inverted‐F antenna)/loop structure, and are divided into two same sub‐arrays which printed on the inner surface of two long frames of the mobile terminal, respectively. All the simulated and measured results present consecutive 6‐dB impedance bandwidth of 3200 to 6500 MHz, acceptable isolations (better than 12 dB), and good total efficiencies (more than 50%). Besides, the proposed wideband 8‐antenna MIMO system has also shown good MIMO performances with ECCs (envelope correlation coefficient) are all lower than 0.08, and ergodic channel capacities are all higher than 37.8 bps/Hz within the entire desired operation bands. In addition, the hand phantom effects are also investigated. The prototype of the proposed wideband eight‐element antenna array is fabricated and measured, and a quite good agreement between simulation and measurement is obtained.

Research on Forensics of Social Network Relationship Based on Big Data

With the development of technologies such as big data, cloud computing, and mobile Internet, many cybercrimes have changed from the previous crime mode of single-person and single-machine to the crime mode of multi-person and multi-machine. Due to the popularity of mobile phones and various mobile terminal applications, many criminals often communicate with other members and commit crimes by mobile phones. Therefore, it is very important for the forensics of the electronic data in the instant communication tools. Much valuable information such as personal common contacts, chat content can be found in the mobile phone, which can help the investigators take the evidence of social network relationship and find many key clues. This paper expounds the forensics mode of social network relationship and the forensics process of mobile phones, and puts forward the forensics method of social network relationship based on Wechat platform, analyses the instance data set, obtains the social network diagram, and intuitively and clearly shows the relationship and intimacy between multiple members. The forensics of Social network relationship can help the investigation organizations narrow the scope of investigation and improve the efficiency of handling cases.

Research on the Translation Teaching System of English Majors Based on Big Data

In the era of big data, with the rise of online media and the wide application of mobile terminals in education and teaching, more and more students rely too much on convenient mobile devices such as tablets and mobile phones to search for videos, audio and text that match their preferences. The network English translation learning resources, over time, lead to resistance to the traditional translation course teaching methods. Especially when teachers use traditional methods to present teaching resources that are duplicated with online resources in the classroom, students will be more resistant to traditional English translation teaching. In this era, the English professional translation course will usher in a new round of teaching reform, and then the author will carry out detailed analysis.