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In the advanced television systems committee (ATSC) 3.0 system, the concept of flexibility is significant for supporting backward compatibility within the same ATSC 3.0 system. However, since the conventional bootstrap signal detection scheme is difficult to support the flexibility, the conventional bootstrap signal detection scheme should be newly designed according to the change of version. In this paper, a convolution neural network (CNN) model for bootstrap signal detection in ATSC 3.0 is proposed to maintain the flexibility of bootstrap. Additionally, for minimizing the loss of error performance of CNN-based bootstrap detection scheme, this paper proposes two dimensional alternate array to utilize the correlation of the adjacent bootstrap symbol and proposes the offline learning method using the bootstrap signal corrupted by noise to improve the error performance.

This paper proposes receive diversity with power adaptation for a non-orthogonal multiple access (NOMA) system in a multi-user circumstance. Since the basic concept of power domain NOMA divides user data by the difference of power, successive interference cancellation (SIC) is necessary to extract user data. In the process of SIC calculation, the error propagation has occurred. Therefore, signal-to-interference-plus-noise ratio (SINR) decreases as the number of user entity increases in a power domain NOMA system. In order to mitigate the inter-user interference, data are allocated to subcarriers with an instantaneous user grouping scheme. With the subcarrier structure of the instantaneous user grouping scheme, this paper proposes receive diversity to improve the bit error rate (BER). However, since the diversity method decreases the sum capacity of the system, a power adaptation method is also proposed to compensate the sum capacity. The simulation results show that the proposed method improves the BER performance than the conventional scheme and increases sum capacity that is decreased by the receiver diversity scheme.

This paper proposes an efficient precoding method based on Neumann series (NS) to improve error performances for already developed diagonal NS (DNS) in massive MIMO system. The conventional DNS has very low complexity compared to a zero-forcing (ZF) and any other NS based ZF precoding methods such as tri-diagonal NS (TNS) and eigenvalue based NS. However, the conventional DNS has very poor error performance in highly correlated massive MIMO system and performance degradations are severe as the used modulation is large. For an efficient precoding, diagonal plus columns NS (DCNS)-1, DCNS- $k$ , and hybrid DCNS-1 and DCNS- $U$ are proposed, and these precoding schemes are adaptively used according to the number of total diagonal dominant active users. The DCNS-1 is applied to fully diagonal dominant users and DCNS- $k$ is applied to non diagonal dominant users, and finally, hybrid DCNS-1 and DCNS- $U$ is applied to partially diagonal dominant systems. For improved DCNS- $k$ , $k$ active users which cause the largest post interference power are selected by simple calculations. The simulation results show that bit error rate (BER) performance for the proposed scheme is very higher than the conventional DNS and is nearly approximated to the BER performance for the conventional optimal ZF with very low complexity.

Smart home and its applications are one of the main interests of IoT (internet of things). Recently, 3GPP has introduced cellular IoT systems including LTE-M and NB-IoT (narrowband IoT). In this letter, we propose a unified frame structure for providing the applications of cellular IoTs to smart home scenario and implement using the USRP-RIO. The experimental results verify the performances of cellular IoTs in smart home environments.

Abstmct-This paper presents a kind of real time obstacle detection method for underwater vehicles equipped with 2D forward looking sonar. Due to frequent failure or multipath effects, it is very often uneasy to get satisfactory sonar range measurements, especially in the water tank environment. How to extract as accurate as possible environmental information from these sonar raw (noisy) measurements is crucial for the vehicle's obstacle avoidance. In this paper, we propose a sort of occupancy grid mapping method to detect the obstacles in a cuboid tank environment, which is assumed to be unknown to the vehicle except for its dimensions. Some of Experimental studies are carried out to demonstrate the effectiveness of presented algorithm.

A new method of reading chipless RFID tags in the near-field region using a microstrip transmission line and resonant coupling with the tags is proposed. A chipless tag consist of combinations of two resonant structures using different resonance methods and resonance frequencies. N-bit codes distinguish 2n types of items by passing over the microstrip transmission line as the reader system. This method can be used effectively in paper/plastic-based items, especially required to improve security as the additional security element. It will be the effective way to identify chipless RFID tags in the near-field region.

Five-port architectures are investigated as a reflectometer for adaptive load impedance matching. The proposed reflectometer requires computationally simple control loop. Moreover, the adaptive load impedance matching system in RFID UHF band are proposed. Using simulation and measurement studies, it is shown that the five-port architecture can be used as a low-cost, simple and high-performance reflectometer in adaptive load matching systems.

For ultra-high frequency (UHF) radio frequency identification (RFID) dead zone avoidance from the viewpoint of antenna configurations and radiation characteristics, a hemispheric coverage mutli-beam switched square quadrifilar spiral antenna (QSA) array using a 4-port feeding network is presented. The proposed antenna array consists of a 2×2 circular polarized QSA array and a 4-port feeding network for multiple beams. It generates single-, dual-, and quad-beams with a hemispheric coverage by a beam switching, and its maximum beam gains and directions are 7.4 dBic and 65°, respectively. By switching multi-beams with the hemispheric coverage, the proposed 2×2 QSA array with a 4-port feeding network improves the tag identification in the dead-zone read area within the reading range.

Based on a dual-beam switching, the wide-coverage array antenna with a 4 × 4 proposed matrix which generates three dual-beams is presented for the ultra high frequency (UHF) radio frequency identification (RFID) applications. The 4 × 4 proposed matrix generates the three dual-beams which can find the approximate location of a tag by covering the wide spatial coverage of 180°. The main beam directions can be controlled by selecting the appropriate input port of the proposed matrix. Due to the compact structure and very low reflection coefficient, the circular polarized square quadrifilar spiral antenna (QSA) array incorporated with the 4×4 proposed matrix has been configured. The fabricated array antenna operates at the 902-928 MHz band and produces three dual-beams at ±12°, ±39°, and ±68°.

In this paper, an analysis results for the protection of a DC micro-grid is described. The 400V DC micro-grid consists of a wind power system (Permanent Magnet Synchronous Generator, PMSG), a photo-voltaic system, a fuel cell system and energy storages. Abnormal operating conditions during various faults are studied. According to a series of studies, a protection scheme for a DC micro-grid is suggested. An algorithm which can be used for discriminating the stable abnormal operating condition from the faults which should be cleared is also presented. All case studies are simulated with PSCAD /EMTDC.

A type of ultra-high frequency (UHF, 840–960MHz) band near-field antenna for RFID applications is proposed. The proposed near-field reader antenna consists of two spiral-shaped transmission lines and lines are parallel to each other. By adjusting the distance between two lines of the reader antenna, the strength of the field between two transmission lines and the recognition distance are able to be controlled. The antenna printed on a FR4 printed circuit board (PCB) with an overall size of 150 × 150 × 1 mm. The proposed near-field reader antenna satisfactorily operates in UHF band, and the measurements show that the proposed antenna has bandwidth of about 350MHz and is capable of detecting UHF RFID tags in 11cm distance for 10 dBm incident power.

In this paper, a ducted fan Uninhabited Aerial Vehicle(UAV), being capable of vertical take-off and landing, is studied to understand characteristics and control of the vehicle. The ducted fan UAV is unstable and susceptible to wind due to its external structural shape. Also the ducted fan UAV must change the attitude to gain speed, so it has different characteristics with respect to velocity. To handle these problems, a fuzzy gain scheduler is introduced and the stability condition is derived. A numerical guidance simulation is performed using a waypoint guidance law.