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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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The Journal of Korean Institute of Communications and Information Sciences
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The Korean Institute of Communications and Information Sciences
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Volume & Issues
Volume 40, Issue 12 - Dec 2015
Volume 40, Issue 11 - Nov 2015
Volume 40, Issue 10 - Oct 2015
Volume 40, Issue 9 - Sep 2015
Volume 40, Issue 8 - Aug 2015
Volume 40, Issue 7 - Jul 2015
Volume 40, Issue 6 - Jun 2015
Volume 40, Issue 5 - May 2015
Volume 40, Issue 4 - Apr 2015
Volume 40, Issue 3 - Mar 2015
Volume 40, Issue 2 - Feb 2015
Volume 40, Issue 1 - Jan 2015
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Double-Input Singe-Output Architecture of LNA and Correction Method of Phase Variation for OTM Satellite Communication System
Kwon, Kun-Sup ; Ryu, Heung-Gyoon ; Heo, Jong-Wan ; Hwang, Ki-Min ; Jang, Myung-Jin ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 1, 2015, Pages 1~8
DOI : 10.7840/kics.2015.40.1.1
In this paper, a double-input single-output architecture of a LNA(Low Noise Amplifier) is presented to enable to be devised for light weight and small-sized OTM(On-The-Move) satellite communication system suitable to be mounted on vehicles. In spite of advantages of the double-input single-output architecture of a LNA such as reduction of the number of physical channels, it results in time-varying phase error between a fundamental mode path and a high-order mode path. This paper shows that the error can be corrected by adding pilot signals to the LNA and using signal processing, and also gives the measurement data to use the method mentioned above.
A CMOS Band-Pass Delta Sigma Modulator and Power Amplifier for Class-S Amplifier Applications
Lee, Yong-Hwan ; Kim, Min-Woo ; Kim, Chang-Woo ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 1, 2015, Pages 9~15
DOI : 10.7840/kics.2015.40.1.9
A CMOS band-pass delta-sigma modulator(BPDSM) and cascode class-E power amplifier have been developed CMOS for Class-S power amplifier applications. The BPDSM is operating at 1-GHz sampling frequency, which converts a 250-MHz sinusoidal signal to a pulse-width modulated digital signal without the quantization noise. The BPDSM shows a 25-dB SQNR(Signal to Quantization Noise Ratio) and consumes a power of 24 mW at an 1.2-V supply voltage. The class-E power amplifier exhibits an 18.1 dBm of the maximum output power with a 25% drain efficiency at a 3.3-V supply voltage. The BPDSM and class-E PA were fabricated in the Dongbu`s 110-nm CMOS process.
Beamforming Power Allocation Method of Multiple Nodes with UCA for Increasing SIR
Park, Seongho ; Park, Chul ; Kim, Hanna ; Chung, Jaehak ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 1, 2015, Pages 16~22
DOI : 10.7840/kics.2015.40.1.16
This paper proposes a power allocation method for multiple node beamforming with uniform circular array antennas to increase SIR of nodes in wireless mesh network. The proposed method calculates beamforming power allocation vectors that maximizes SIR satisfied with power constraint of HPA. The simulation results demonstrate the proposed method achieves the enhanced SIR of nodes than that of beamforming method.
Design and Performance Evaluation of SSD (Simultaneous Single Band Duplex) System with HPA Nonlinearity
Keum, Hong-Sik ; An, Changyoung ; Ryu, Heung-Gyoon ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 1, 2015, Pages 23~31
DOI : 10.7840/kics.2015.40.1.23
In this paper, we design a SSD(simultaneous single band duplex) system using RF cancellation and digital cancellation. And then, we analyze performance of the SSD system using pre-distorter with HPA non-linearity. Also, we analyze digital cancellation performance of the SSD system using pre-distorter with HPA non-linearity. Additionally, digital cancellation cancels residual self-interference. In linear conditions, digital cancellation can cancel self-interference of 40dB. Therefore, the SSD system has good BER performance because most of self-interference is canceled. But, in HPA non-linearity conditions, digital cancellation cancels residual self-interference of 25dB. In this conditions, self-interference is greater than desired signal. Therefore, bit informations of distant station can not be received. But, we confirm that if the proposed system uses pre-distorter then bit information of distant station can be received by HPA non-linearity compensation. Also, we confirm that even though the proposed system uses pre-distorter, if HPA non-linearity increases then digital cancellation performance is degraded by imperfect compensation of HPA non-linerity.
Resource Allocation and Power Control for Device-to-Device Communication in LTE-Advanced Based on User Area Information
Li, Xiang ; Shin, Oh-Soon ; Shin, Yoan ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 1, 2015, Pages 32~42
DOI : 10.7840/kics.2015.40.1.32
In this paper, we considered the scenario that one cellular link and muti-D2D links share the same frequency resource which can improve the spectrum efficiency during uplink communication in LTE (Long Term Evolution)-Advanced network. In order to reduce the interference caused to the D2D users, we set DME (Discovery and Management Entity) which can send the area information to eNB(evolved Node B). We proposed a resource allocation scheme by using these assistant devices to reduce the interference that CUE (Cellular User Equipment) causes to DUE Rx (D2D UE Receiver). Basing on the area information, in order to mitigate the interference among the D2D pairs which share the same frequency resource, a power control scheme has been proposed. The simulation results prove that by using the DMEs, the proposed schemes improve the stability of D2D communication and bring the highest performance of the communication system when comparing to the other different schemes.
Interference Aware Downlink Channel Allocation Algorithm to Improve Throughput on OFDMA Cellular Multihop Networks with Random Topology
Lim, Sunggook ; Lee, Jaiyong ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 1, 2015, Pages 43~51
DOI : 10.7840/kics.2015.40.1.43
Upcoming cellular networks such as LTE-advanced and IEEE 802.16m are enhanced by relay stations to support high data rate multimedia services and minimize the shadow zone with low cost. Enhancing the relay stations, however, divides the multihop cellular network into smaller microcells and the distance between microcells is closer, which intends large intra-cell and inter-cell interference. Especially the access link on downlink in the OFDMA cellular network is the throughput bottleneck due to the severe interference caused by base stations and relay stations transmitting large data to mobile stations simultaneously. In this paper, we present interference aware channel allocation algorithm to avoid severe interference on multihop cellular networks with random topology. Proposed algorithm increases SINR(signal to interference plus noise ratio) and decreases number of required control messages for channel allocation, so that increases overall throughput on the networks.
Lattice-Based Background Motion Compensation for Detection of Moving Objects with a Single Moving Camera
Myung, Yunseok ; Kim, Gyeonghwan ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 1, 2015, Pages 52~54
DOI : 10.7840/kics.2015.40.1.52
In this paper we propose a new background motion compensation method which can be applicable to moving object detection with a moving monocular camera. To estimate the background motion, a series of image warpings are carried out for each pair of the corresponding patches, defined by the fixed-size lattice, based on the motion information extracted from the feature points surrounded by the patches and the estimated camera motion. Experiment results proved that the proposed has approximately 50% faster in execution time and 8dB higher in PSNR comparing to a conventional method.
Adaptive Non-Local Means Denoising Algorithm Using Down-Scaled Images
Nguyen, Tuan-Anh ; Kim, Dong Young ; Hong, Min-Cheol ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 1, 2015, Pages 55~57
DOI : 10.7840/kics.2015.40.1.55
This paper presents an adaptive non-local means denoising algorithm using down-scaled images. This work provides a method to reduce artifacts and information loss around context region by increasing the number of similar patches for high activity region with down-scaled images. Experimental results demonstrate that the proposed algorithm outperforms the non-local means algorithm more than 1.5 (dB).
Open-Loop Precoding for Spatial Multiplexing Systems in Correlated Channels
Jang, Jungyup ; Kim, Dong Ho ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 1, 2015, Pages 58~60
DOI : 10.7840/kics.2015.40.1.58
In this letter, an open-loop precoding is proposed to enhance the performance of SM in transmit correlated MIMO channels. The proposed method is derived by observing the effect of feedback error on the minimum distance precoder, and can mitigate the performance degradation without any feedback information.
Energy-Aware Virtual Machine Deployment Method for Cloud Computing
Kim, Minhoe ; Park, Minho ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 1, 2015, Pages 61~69
DOI : 10.7840/kics.2015.40.1.61
Through Virtual Machine technology(VM), VMs can be packed into much fewer number of physical servers than that of VMs. Since even an idle physical server wastes more than 60% of max power consumption, it has been considered as one of energy saving technologies to minimize the number of physical servers by using the knapsack problem solution based on the computing resources. However, this paper shows that this tightly packed consolidation may not achieve the efficient energy saving. Instead, a service pattern-based VM consolidation algorithm is proposed. The proposed algorithm takes the service time of each VM into account, and consolidates VMs to physical servers in the way to minimize energy consumption. The comprehensive simulation results show that the proposed algorithm gains more than 30% power saving.
Performance Evaluation of MPTCP over Shared Bottleneck Link
Nguyen, Van Dien ; Ro, Soonghwan ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 1, 2015, Pages 70~77
DOI : 10.7840/kics.2015.40.1.70
In this paper, we present experimental results evaluating the performance of the Multipath TCP over shared bottleneck path in series of benchmark tests. In summary, we find that the Multipath TCP`s fairness as well as its competitive responds to the change of network conditions such as latency, loss rate
MPTCP is extremely unfair and powerful with regular TCP in ideal network conditions but its throughput decreases clearly even less than regular TCP in worse network conditions with very high latency, higher packet loss rate.
Popularity-Based Pushing Scheme for Supporting Content Provider Mobility in Content-Centric Networking
Woo, Taehee ; Park, Heungsoon ; Kwon, Taewook ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 1, 2015, Pages 78~87
DOI : 10.7840/kics.2015.40.1.78
Content-Centric Networking(CCN) is a new networking paradigm to search for the routing information needed to find a data from the content name, unlike conventional IP networks. In CCN, the mobility management, one of the CCN challenges, is consists of consumer mobility and content provider mobility. Among both, in the case of the content provider mobility, it requires too much overhead and time to update routing information on the corresponding routers. In this paper, we propose Popularity-based Pushing CCN(PoPCoN) which considers the content popularity to support effective mobility of content provider in CCN. Our proposed algorithm shortens content download time for the consumer and reduces the network overhead during mobility as compared to the existing approaches.
Efficient Localization Algorithm for Non-Linear Least Square Estimation
Lee, Jung-Kyu ; Kim, YoungJoon ; Kim, Seong-Cheol ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 1, 2015, Pages 88~95
DOI : 10.7840/kics.2015.40.1.88
This paper presents the study of the efficient localization algorithm for non-linear least square estimation. Although non-linear least square(NLS) estimation algorithms are more accurate algorithms than linear least square(LLS) estimation, NLS algorithms have more computation loads because of iterations. This study proposed the efficient algorithm which reduced complexity for small accuracy loss in NLS estimation. Simulation results show the accuracy and complexity of the localization system compared to the proposed algorithm and conventional schemes.
Multi-Channel MAC Protocol Based on V2I/V2V Collaboration in VANET
Heo, Sung-Man ; Yoo, Sang-Jo ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 1, 2015, Pages 96~107
DOI : 10.7840/kics.2015.40.1.96
VANET technologies provide real-time traffic information for mitigating traffic jam and preventing traffic accidents, as well as in-vehicle infotainment service through Telematics/Intelligent Transportation System (ITS). Due to the rapid increasement of various requirements, the vehicle communication with a limited resource and the fixed frame architecture of the conventional techniques is limited to provide an efficient communication service. Therefore, a new flexible operation depending on the surrounding situation information is required that needs an adaptive design of the network architecture and protocol for efficiently predicting, distributing and sharing the context-aware information. In this paper, Vehicle-to-Infrastructure (V2I) based on communication between vehicle and a Road Side Units (RSU) and Vehicle-to-Vehicle (V2V) based on communication between vehicles are effectively combined in a new MAC architecture and V2I and V2V vehicles collaborate in management. As a result, many vehicles and RSU can use more efficiently the resource and send data rapidly. The simulation results show that the proposed method can achieve high resource utilization in accordance. Also we can find out the optimal transmission relay time and 2nd relay vehicle selection probability value to spread out V2V/V2I collaborative schedule message rapidly.
A Research on Performance Improvement of iBeacon Using Transmission and Reception of Different Beacon Signals
Kim, Cheol-Hoon ; Hong, Seung-Hyun ; Lee, Sung-Won ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 1, 2015, Pages 108~114
DOI : 10.7840/kics.2015.40.1.108
In this paper, we propose a different kind of Beacon signals transmission and receipt scheme to express more information in existing iBeacon. Because the user can only use Major and Minor of iBeacon, information available for the user is limited to 4byte. The proposed scheme makes it possible to use more information by transmitting consecutively a different kind of Beacon signals that major and minor are different. When it comes to using more information of iBeacon, it is possible to recognize people and objects using iBeacon and utilization range of iBeacon is widened further. Also, we verify operation of the proposed scheme through application implementation.
A Study on Determinants of Consumers` Choice of Mobile Data Service
Choi, Sae-Sol ; Han, Sung-Soo ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 1, 2015, Pages 115~123
DOI : 10.7840/kics.2015.40.1.115
As LTE service and smartphone are emerging as the mainstream of mobile communications market, the value and importance of mobile data service has been further increased. MNO(mobile network operator)s already recognized the data service as essential market needs, and have appealed to consumers based on various satisfaction elements of data service such as faster transmission speed, expended data volume provided as default, and introduction of unlimited plan. So, in the smartphone market where has been mature, investigating what service attributes affect users` selection of data service is very meaningful from the perspectives of both the industry and the academic. Under this background, this study explores determinants influencing consumer`s choice for mobile data service and analyzes relative importance of the attributes among different type of users. The findings of this study makes us extend our understanding of consumer characteristics and their service needs in data service centric era, and it provides some implications for establishing telecommunications policies and business strategies.
Pedestrian Positioning Method using Multi-Level Transmission Signal Strength
Lee, Myung-Su ; Kim, Ju-Won ; Lee, Sang-Sun ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 1, 2015, Pages 124~131
DOI : 10.7840/kics.2015.40.1.124
In this paper, we proposed indoor positioning system using RSS(Received Signal Strength) positioning method and TSS(Transmission Signal Strength). The main point in the paper is to improve reliability of accuracy positioning with the area recognition algorithm and probabilistic algorithm, which can be effectively used indoor. In the test in 1-dimensional or 2-dimensional spaces, also we checked effective positioning system considered environment of propagation that is changed by reflection, refraction and multipath in according to space form. It is necessary to find place where urgent situation happen and quickly to respond the situation for patients or the weak. Therefore, we expect the positioning system proposed can apply to the field of traffic IT.
Technology Review on Multimodal Biometric Authentication
Cho, Byungchul ; Park, Jong-Man ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 1, 2015, Pages 132~141
DOI : 10.7840/kics.2015.40.1.132
There might have been weakness in securing user authentication or verification with real time service approach, while existing unimodal biometric authentication has been used mainly for user identification and recognition. Accordingly, it is essential to research and develop ways that upgrade security performance with multi biometric based real time authentication and verification technology. This paper focused to suggest binding assignment and strategy for developing multi biometric authentication technology through investigation of advanced study and patents. Description includes introduction, technology outline, technology trend, patent analysis, and conclusion.
Detection of Objects Temporally Stop Moving with Spatio-Temporal Segmentation
Kim, Do-Hyung ; Kim, Gyeong-Hwan ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 1, 2015, Pages 142~151
DOI : 10.7840/kics.2015.40.1.142
This paper proposes a method for detection of objects temporally stop moving in video sequences taken by a moving camera. Even though the consequence of missed detection of those objects could be catastrophic in terms of application level requirements, not much attention has been paid in conventional approaches. In the proposed method, we introduce cues for consistent detection and tracking of objects: motion potential, position potential, and color distribution similarity. Integration of the three cues in the graph-cut algorithm makes possible to detect objects that temporally stop moving and are newly appearing. Experiment results prove that the proposed method can not only detect moving objects but also track objects stop moving.
Smart Camera Technology to Support High Speed Video Processing in Vehicular Network
Son, Sanghyun ; Kim, Taewook ; Jeon, Yongsu ; Baek, Yunju ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 1, 2015, Pages 152~164
DOI : 10.7840/kics.2015.40.1.152
A rapid development of semiconductors, sensors and mobile network technologies has enable that the embedded device includes high sensitivity sensors, wireless communication modules and a video processing module for vehicular environment, and many researchers have been actively studying the smart car technology combined on the high performance embedded devices. The vehicle is increased as the development of society, and the risk of accidents is increasing gradually. Thus, the advanced driver assistance system providing the vehicular status and the surrounding environment of the vehicle to the driver using various sensor data is actively studied. In this paper, we design and implement the smart vehicular camera device providing the V2X communication and gathering environment information. And we studied the method to create the metadata from a received video data and sensor data using video analysis algorithm. In addition, we invent S-ROI, D-ROI methods that set a region of interest in a video frame to improve calculation performance. We performed the performance evaluation for two ROI methods. As the result, we confirmed the video processing speed that S-ROI is 3.0 times and D-ROI is 4.8 times better than a full frame analysis.
Absolute Altitude Determination for 3-D Indoor and Outdoor Positioning Using Reference Station
Choi, Jong-Joon ; Choi, Hyun-Young ; Do, Seoung-Bok ; Kim, Hyun-Soo ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 1, 2015, Pages 165~170
DOI : 10.7840/kics.2015.40.1.165
The topic of this paper is the advanced absolute altitude determination for 3-D positioning using barometric altimeter and the reference station. Barometric altimeter does not provide absolute altitude because atmosphere pressure always varies over the time and geographical location. Also, since Global Navigation Satellites system such as GPS, GLONASS has geometric error, the altitude information is not available. It is the reason why we suggested the new method to improve the altitude accuracy. This paper shows 3-D positioning algorithm using absolute altitude determination method and evaluates the algorithm by real field tests. We used an accurate altitude from RTK system in Seoul as a reference data and acquired the differential value of pressure data between a reference station and a mobile station equipped in low cost barometric altimeter. In addition, the performance and advantage of the proposed method was evaluated by 3-D experiment analysis of PNS and CNS. We expect that the proposed method can expand 2-D positioning system 3-D position determination system simply and this 3-D position determination technique can be very useful for the workers in the field of fire-fighting and construction.
Development of Medical Rehabilitation Game and Rehabilitation Possibility Using EMG and Gyroscope Signal
Lim, Jong Heon ; Lee, Joon Jae ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 1, 2015, Pages 171~182
DOI : 10.7840/kics.2015.40.1.171
For fast recovery from physical discomfort and getting back to normal life, many rehabilitation treatments have been performed on patients. Computer games have been one of such treatments that are able to apply to patients effectively. However, because most of such games are locational-based, it is hard to figure out exact medical condition of patients that provide more information to medical doctors. This paper presents a rehabilitation game for patients, which is locational-based as well as rotational-based, who are having external wound or aging diseases by using electromyography signal and gyroscopic sensors. Through this game, we are able to understand how to lead the patients to involve in physical therapy more and how to obtain exact conditions of patients from the games. From several experiments, we found out that our games are able to make patients to increase their physical activity and possibility.
Design and Measured Data Analysis of a Shipboard Indoor Signal Propagation Characteristics Based on Signature Sequence-Two Way Packet Mode
Kim, Jeong-Ho ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 1, 2015, Pages 183~186
DOI : 10.7840/kics.2015.40.1.183
Recently, the demand for the safety and the information delivery system in the ship increases. The deployment of the wireless sensor networks instead of using the built-in wired networks or the setup of the new wired networks is more desirable than the deployment of the wired networks in a ship after its final production since it can reduce the cost and the time of the brand new wired networks by deforming some of the internal structure of the ship. In this paper, the shipboard signal propagation measurement system based on the signature sequence-two way slave mode are designed and its measurement data are analysed after measuring the signal propagation characteristics. Consequently, it is expected that the reliable and cost-effective signal measurement system for the deployment of the shipboard wireless networks can be built.
Doppler Frequency Estimation for Time-Varying Underwater Acoustic Communication Channel
Hwang, Chan-Ho ; Kim, Ki-Man ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 1, 2015, Pages 187~192
DOI : 10.7840/kics.2015.40.1.187
Underwater acoustic communication channels have very complex channel characteristics caused by time-varying sea surface, submarine topography, sound speed, and geometry between transmitter and receiver. Especially, the channel has time-variance and doppler effect due to wind and sea current. We have to recognize the channel state and apply it to communication technique for increasing transmission efficiency in the underwater acoustic channel. In this paper, we present the frame recursive modulation and demodulation method using ambiguity function and autocorrelation function to estimate the doppler frequency. Furthermore, we conducted the simulation and sea experiment to evaluate the performance of the proposed method. When the channel coding technique was not used, the bit error rate performance of the proposed method was improved about 32 % compared with conventional method.
Design and Measured Data Analysis of a Shipboard Indoor Signal Propagation Characteristics Based on Three Way Signature Sequence Packet Mode
Kim, Jeong-Ho ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 1, 2015, Pages 193~197
DOI : 10.7840/kics.2015.40.1.193
Recently, the new issues for the safety and the information delivery system in the ship are raised. The deployment and the efficient algorithms of deploying the wireless sensor networks instead of using the built-in wired networks or the setup of the new wired networks is more desirable than the deployment of the wired networks in a ship after its final production since it can reduce the cost and the time of the brand new wired networks by reshaping some of the internal structure of the ship. In this paper, the shipboard signal propagation measurement system based on the signature sequence-three way slave mode are designed and its measureed data are analysed after measuring the signal propagation characteristics. Consequently, it is expected that the reliable and cost-effective signal measurement system with the three way algorithm for the deployment of the shipboard wireless networks can be achieved.
Location Determination and Measured Data Analysis of a Shipboard Indoor Signal Propagation Characteristics Based on Signature Sequence
Kim, Jeong-Ho ; Lee, Seong-Ro ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 1, 2015, Pages 198~201
DOI : 10.7840/kics.2015.40.1.198
The prompt and accurate location determination of the nodes of the wireless indoor shipboard networks is crucial to forming the stable wireless shipboard sensor networks. To this end in this paper it can be achieved through the measurement of the bi-directional channel qualities among the nodes after the locations of the sensor nodes temporarily placed. For the 1st stage the piconet-type sensor networks are considered to measure the channel qualities between a specific node and the cluster node which is the master node. After finishing the 1st stage measurement the nodes needing the relay nodes are selected and the measurement action goes into the 2nd stage. In the 2nd stage the measurement between a candidate relay node and the node needing a relay node starts to begin. After the 2nd stage the relay nodes to connect to the cluster node are fixed and the information delivery paths between a node and the cluster head are established. In this paper the measurement results in the realistic environment are gathered and analysed to show that the measurement procedure can be applied in the wireless indoor shipboard networks.
Performance Analysis of Relay-Based Shipboard Wireless Communication Systems
Joo, Yang-Ick ; Kim, Beom-Mu ; Jeong, Min-A ; Lee, Seong Ro ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 1, 2015, Pages 202~208
DOI : 10.7840/kics.2015.40.1.202
A wireless ship area network is required to configure and control various sensors and electrical instruments embedded or boarded in a ship. In such environment, wireless communication protocol adopting relaying function is needed because direct link or communication between two nodes is hardly guaranteed due to spatial constraints in a ship. In this study, we introduce and analyze a WiMedia Distributed MAC (D-MAC) based approach considering throughput and energy constraint of wireless communication module. Performance evaluation results demonstrate that the relay-based wireless communication protocol improves reliability of wireless communication network in a ship.
RCS of Ballistic Missile Based on Radar Position
Park, Tae-Yong ; Lim, Jae-Sung ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 1, 2015, Pages 209~216
DOI : 10.7840/kics.2015.40.1.209
It is difficult to detect, track and intercept ballistic missile because of its high speed and short flight time from launching to target area. In order to increase the success rate of a ballistic missile interceptor, it is important to track the flight trajectory for a long time after the detection in the early launch. Radar Cross Section(RCS) of the target is important when the target to be detected by the radar, and the difference between the RCS value greatly changes depending on the viewing direction during the flight missile trajectory. In this paper, it is assumed that a ballistic missile is launched at east coast of North Korea, observe that missile by a land based radar and sea deployed radar. And it is analyzed and compared that RCS difference of ballistic missile.
Analysis of Indoor Localization Technology for Exhibition Services and Application Method of VLC/RF Converged Localization
Kim, Ki-Yun ; Lee, Min-Woo ; Cha, Jae-Sang ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 1, 2015, Pages 217~225
DOI : 10.7840/kics.2015.40.1.217
Recently, as the supply of smart phone is spreading and the exhibition industries are rapidly growing, future exhibitions are evolving toward active, customized, interactive, tangible services, which can give more satisfaction to visitors. To realize this services, the indoor localization in the exhibition of visitors is very important and according to the accuracy of localization the quality of services for exhibition are also different. In this paper, state-of-the art indoor localization techniques are investigated and new localization method are proposed. To achieve this goal, future exhibition service types are proposed, which are connected with IT technology. And also, BLE(Bluetooth Low Energy) technology including comparison of specifications and representative localization technologies are analysed. Furthermore we performed comparison study and simulation between RF and VLC channels. Finally based on this, we proposed converged VLC and RF(Wi-Fi and BLE) localization technique for exhibition.
Position Information Acquisition Method Based on LED Lights and Smart Device Camera Using 3-Axis Moving Distance Measurement
Jung, Soon-Ho ; Lee, Min-Woo ; Kim, Ki-Yun ; Cha, Jae-Sang ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 1, 2015, Pages 226~232
DOI : 10.7840/kics.2015.40.1.226
As the age of smart device has come, recently many application services related to smart phone are developing. The LBS(Location Based Service) technique is considered as one of the most important techniques to support location based application services. Usually the smart phone acquires the information of position by using the position recognition systems and sensors such as GPS(Global Positioning System) and G-Sensor. However, since the GPS signal from the satellite can hardly be received in the indoor environments, new LBS techniques for the indoor environment are required. In this paper, to solve the problem a position information transceiver using LED lights and smart phone camera sensor is proposed. We proved the possibility of the proposed positioning system through the experiments in the laboratory for the practical verification.
Design and Implementation of LED Streetlight System for Remote Control and Wi-Fi Service
Lee, Sang Hoon ; Shin, Soo Young ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 1, 2015, Pages 233~239
DOI : 10.7840/kics.2015.40.1.233
The demand of remote control and monitoring for efficiency and applications of LED streetlight is increasing continuously because the demand of LED streetlight was increase last few years. Existing street light remote control system is wired using a power line network. The wireless connection exists, but due to its low data transmission rate, it cannot support specialized applications. It can only support simple control and monitoring. In this paper, we propose a system that uses a IEEE 802.11s wireless mesh network based on WLAN, as a backbone network for remote control and monitoring of the LED street lights along with other specialized applications. Using the wireless mesh network for remote control and monitoring the LED street lights, the same can be used to act like a public Wi-Fi access point. We have designed Wi-Fi integrated LED streetlight controller and implemented our system. We evaluated the performance of our system on a real test bed. Our proposed system is expected to perform the role of a U-city infrastructure by utilizing the wireless mesh network.
Spectral Analysis of Flickering Effects in Binary Dimmable Visible Light Communication
Lee, Sang Hyun ; Kwon, Jae Kyun ;
The Journal of Korean Institute of Communications and Information Sciences, volume 40, issue 1, 2015, Pages 240~245
DOI : 10.7840/kics.2015.40.1.240
This paper presents an impact of flicker for various binary modulations of visible light communication (VLC) under dimming requirement. While previous approaches consider the statistics of the signal that cannot capture contributions of dynamic impacts of flicker, the power spectral density is evaluated for various VLC transmission schemes of dimming support. This enables to compare transmission schemes with the contribution of low and intermediate frequency components to flicker. Numerical results show that analog dimming has advantages over other techniques in terms of flicker and signal processing with waveforms and symbol distribution allows to mitigate flicker effects.