• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.41 no.1
• /
• pp.69-76
• /
• 2004

Recently, The development of DTV receiver and the need of its additional services have been increased vastly. In this paper, we implement new closed caption engine for the deaf and hard of hearing person and languages studying on DTV receiver, The specification of domestic closed caption is almost adopted that of EIA-608A. In this paper, with fully following the specification, we will present how to implement functions of closed caption with new algorithm. the function includes paint-on, Pop-on, roll-up/down, etc. experimental results show that the proposed technique provides satisfactory performance on DTV receiver.

• Journal of Positioning, Navigation, and Timing
• /
• v.6 no.1
• /
• pp.1-8
• /
• 2017

In this study, to design a multi-GNSS receiver using single RF front-end, the receiving performances for various frequency plans were evaluated. For the fair evaluation and comparison of different frequency plans, the same signal needs to be received at the same time. For this purpose, two synchronized RF front-ends were configured using USRP X310, and PC-based software was implemented so that the quality of the digital IF signal received at each front-end could be evaluated. The software consisted of USRP control, signal reception, signal acquisition, signal tracking, and C/N0 estimation function. Using the implemented software and USRP-based hardware, the signal receiving performances for various frequency plans, such as the signal attenuation status, overlapping of different systems, and the use of imaginary or real signal, were evaluated based on the C/N0 value. The results of the receiving performance measurement for the various frequency plans suggested in this study would be useful reference data for the design of a multi-GNSS receiver in the future.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.44 no.3
• /
• pp.212-217
• /
• 2016

The S-band receiver for Low Earth Orbit satellite is designed and fabricated as engineering model. Demodulator is implemented by using FPGA for extension of demodulator method. The receiver consists of RF Block, Digital demodulator and Power stage and has a Doppler tracking function to compensate a frequency shift that occur on the operation. The measured results of fabricated receiver show BER of less than $1.0{\times}10^{-6}$ at -110dBm RF input power and equipped a frequency tracking of ${\pm}100KHz$ relative to the center frequency. TID test was satisfied with the results of the test criterion is 10krad.

• Journal of Korea Society of Industrial Information Systems
• /
• v.11 no.3
• /
• pp.82-89
• /
• 2006

Optical transmission system related to network infra of ubiquitous is a essential bridge technique between metro network and access point. So, it is need to develop this technique. In this paper, we develop 1Gbps SNMP optical transmitter/receiver system based on 1 core ring-type WDM PON. The developed system can reduce number of optic fiber and doesn't need extra transmitter/receiver. Also, this system can extend nodes owing to many node per wavelength, acts rapidly against security cutting, and acts independent of protocols.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.22 no.3
• /
• pp.332-340
• /
• 2019

Electronic warfare systems are needed to be advantageous in the modern war. Many radar threat signals with various frequency spectrums and complicated techniques exist. For detecting the threats, a receiver with wide and narrow-band digital processing is needed. To process a wide-band searching mode, a polyphase filter bank has become the architecture of choice to efficiently detect threats. A polyphase N-path filter aligns the re-sampled time series in each path, and a discrete Fourier transform aligns phase and separates the sub-channel baseband aliases. Multiple threats and CW are detected or rejected when the signals are received in different sub-channels. And also, to process a narrow-band precision mode, a direct down converter is needed to reduce aliasing by using a decimation filter. These digital logics are designed in a FPGA. This paper shows how to design and develop a wide and narrow-band digital receiver that is capable to detect the threats.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.21 no.11
• /
• pp.1304-1310
• /
• 2010

This study is to design FMCW radar transceiver of K-band which is used to detect and track approaching high speed targets with low altitude. The transmitter needs high output power due to small RCS targets and wide beamwidth of transmit antenna. Multi-channel receivers are required to detect and track targets by interferometer method. Transmitter consists of high power amplifier, waveguide switch, and frequency up-converter. Receiver is composed of five channel receivers, up and down converters, X-band local oscillator and waveform generator. Before manufacturing it, the proposed architecture of transceiver is proved by modeling and simulation using several parameters. Then, it is manufactured by using industrial RF components. The performance parameters are measured through experiment. In the experiment, transmitting power and receiver gain were measured with 39.64 dBm and 29.1 dB, respectively. All other parameters in the specification were satisfied as well.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.22 no.3
• /
• pp.299-311
• /
• 2011

In this paper, we have identified the system instability factors in a bistatic radar system using pulse chasing and considered their effects on the bistatic receiver's MTI(Moving Target Indication) improvement performance. The pulse chasing is a scan method that searchs a restricted area on the transmit pulse-to-pulse basis and the MTI filter is a signal processing that separates a target from some kinds of interferences such as clutter using small number of transmit pulses. Ideal MTI processing performance, e.g., clutter attenuation and improvement, has been limited by the property of the clutter itself, however, the MTI performance in a proposed bistatic receiver configuration could be affected by the receiving beam pointing error during pulse chasing scanning. Also, for the bistatic receiver, we have defined other system instability factors, which result from the time synchronization error, COHO's phase error, the frequency/phase synchronization error, and have analyzed their effects on the system performance improvement.

• Journal of Advanced Navigation Technology
• /
• v.14 no.3
• /
• pp.336-342
• /
• 2010

GPIR(GPS Position Information Revision) system is a new concept of GPS system which utilizes database containing the location of taking a picture by the existing GPS, an angle between a camera and a subject and the location information of buildings and minimizes the GPS's own margin of error and there by provides the services, such as location-guiding via GPS and way-guiding via navigation in an exact and precision way more than before. GPIR system comprehends the location of taking photos via GPS information saved in G-files, searches database in the direction of taking a photo at a photo-taking position via location information and the photo-taking directional angle. And GPIR system corrects the GPS information searched to the location of a subject, again saves such information in a G-file and is ready for receiving more detailed location of the subject. This study explores into the design and development of a receiver which a GPIR user is able to utilize its system as well as the design of the receiver's prototypes.

• Journal of Ocean Engineering and Technology
• /
• v.28 no.5
• /
• pp.440-451
• /
• 2014

A multi-static SONAR system consists of the transmitters and receivers separately in space. The active target echoes are received along the transmitter-target-receiver path and depend on the shape and aspect angle of the submerged objects at each receiver. Thus, the target echo algorithm used with a mono-static system, in which the transmitter and receiver are located at the same position, has limits in simulating the target echoes for a multi-static SONAR system. In this paper, a target echo modeling procedure for a 3D submerged object in space is described based on the Kirchhoff approximation, and the SONAR system is extended to a multi-static SONAR system. The scattered field from external structures is calculated on the visible surfaces, which is determined based on the locations of the transmitter and receiver. A series of experiments in an acoustic water tank was conducted to measure the target echoes from scaled targets with a single transmitter and 16 receivers. Finally, the numerical results were compared with experimental results and shown to be useful for simulating the target echoes/target strength in a multi-static SONAR system.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.22 no.9
• /
• pp.858-867
• /
• 2011

In this paper, we propose a microwave radiometer for remote sensing of oil spills on the water surface. In order to achieve the development aim of the measurement accuracy within 0.2 mm for oil slicks of 0~4 mm thickness, the requirements of the microwave radiometer and the specifications of its receiver are drawn. From these requirements and specifications, the receiver with high gain, high sensitivity is designed and implemented. The receiver has the bandwidth of 58 MHz, the system gain of 47.3 dB and the sensitivity of 0.46 K at 10.65 GHz. The processes of design and implementation of the receiver are described in this paper. The effectiveness of the proposed microwave radiometer in the measurement of oil slicks is demonstrated experimentally. The results show the microwave radiometer can detect the oil slicks for 0~5 mm thickness within the accuracy of 0.13 mm successfully.