• The Magazine of the IEIE
• /
• v.29 no.7
• /
• pp.51-58
• /
• 2002

This paper describes functions required for implementation of digital television (DTV) broadcast receivers. The necessary functions for the DTV receiver vary with the transmission media-terrdstrial, cable and satellite. This paper briefly introduces its hardware and software structure, This paper also presents the future of DTV receivers according to the tomorrow's broadcast environment.

• Journal of Navigation and Port Research
• /
• v.31 no.5 s.121
• /
• pp.409-414
• /
• 2007

The effect of multipath is especially serious in urban area and sea surface where buildings and water reflect GPS signal. Multipath brings about the performance degradation on many GPS application because the presence of multipath causes the diminution of pseudorange measurement accuracy in turn position accuracy. In this paper, a multipath mitigation named weighted correlation method is implemented on software GPS receiver, in which the asymmetric correlation function is compensated by modifying the late correlation value. Asymmetry compensation is obtained as weighted sum of two correlators which have different early-late chip spaces. This structure is adopted to lessen the computation load lower keeping up performance similar to that. The performance of implemented multipath mitigation technique is evaluated using GPS signal and multipath signal generated by GPS signal generator and software GPS receiver. The test results show that the weighted correlation method gives hefter performance than the standard correlator and the narrow correlator.

• Journal of Korea Multimedia Society
• /
• v.6 no.5
• /
• pp.889-895
• /
• 2003

In this paper, we develop a PC adapter board and application software that do not use mouse or keyboard but the infrared communication, which can control the operation remotely. The infrared communication adapter is made up of the infrared receiver part and the serial communication interface part. The infrared receiver part creates a suitable scan-code using the received signal from the infrared transmitter (remote-controller). The serial communication interface part transmits the scan-code to PC by a serial communication. We implement its application softwares to listen to music and see movies. We can control their operations such as play, stop, pause and volume control remotely.

• Journal of Positioning, Navigation, and Timing
• /
• v.12 no.1
• /
• pp.75-81
• /
• 2023

In this study, we design an optimized Graphics Processing Unit (GPU)-based GNSS signal processing technique with the goal of designing and implementing a GNSS Software Defined Receiver (SDR) that can operate in real time all-in-view mode under multi-constellation and multi-frequency signal environment. In the proposed structure the correlators of the existing GNSS SDR are processed by the GPU. We designed a memory structure and processing method that can minimize memory access bottlenecks and optimize the GPU memory resource distribution. The designed GNSS SDR can select and operate only the desired GNSS or desired satellite signals by user input. Also, parameters such as the number of quantization bits, sampling rate, and number of signal tracking arms can be selected. The computing capability of the designed GPU-based GNSS SDR was evaluated and it was confirmed that up to 2400 channels can be processed in real time. As a result, the GPU-based GNSS SDR has sufficient performance to operate in real-time all-in-view mode. In future studies, it will be used for more diverse GNSS signal processing and will be applied to multipath effect analysis using more tracking arms.

• Journal of Broadcast Engineering
• /
• v.21 no.5
• /
• pp.803-815
• /
• 2016

In this paper, we design a direct radio frequency (RF) sampling receiver for multiband GNSS signals and demonstrate its performance. The direct RF sampling is a technique that does not use an analog mixer, but samples the passband signal directly, and all receiver processes are done in digital domain, whereas the conventional intermediate frequency (IF) receiver samples the IF band signals. In contrast to the IF sampling receiver, the RF sampling receiver is less complex in hardware, reconfigurable, and simultaneously converts multiband signals to digital signals with an analog-to-digital (AD) converter. The reconfigurability and simultaneous reception are very important in military applications where rapid change to other system is needed when a system is jammed by an enemy. For simultaneous reception of multiband signals, the sampling frequency should be selected with caution by considering the carrier frequencies, bandwidths, desired intermediate frequencies, and guard bands. In this paper, we select a sampling frequency and design a direct RF sampling receiver to receive multiband global navigation satellite system (GNSS) signals such as GPS L1, GLONASS G1 and G2 signals. The receiver is implemented with a commercial AD converter and software. The receiver performance is demonstrated by receiving the real signals.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.27 no.2
• /
• pp.247-255
• /
• 2024

Development of electronic warfare(EW) software has become increasingly challenging due to stricter regulations, shorter development cycles, and increased reliability testing. Consequently, software development often proceeds without proper architecture design, which can lead to missing critical quality requirements and potential system redesigns. In this study, we propose using Attribute-Driven Design(ADD) 3.0 to design software architecture specifically tailored for EW systems, enabling a more systematic approach to address quality requirements. The paper presents an overview of EW software and ADD 3.0 methodology, followed by an analysis of the architecture design results using static and dynamic views. The paper concludes by discussing the effectiveness of the proposed architecture design.

• Journal of Advanced Navigation Technology
• /
• v.13 no.3
• /
• pp.319-326
• /
• 2009

In this paper, the key technologies of Navigation receiver for GNSS sensor station are presented as a development result of a GNSS ground station in ETRI. A wide-band antenna and RF/IF components and SW signal processing unit to cover the GPS and Galileo signals for GNSS receiver are developed and its performance is verified by using GPS live signal and GNSS RF signal simulator from SpirentTM. We also gather GIOVE-A signal by using H/W antenna and RF/IF units in IF-level as sampling frequency and bit number, 112MHz and 8bits, respectively by using the developed wide-band antenna and RF/IF components. Data acquisition is done by using commercial data acquisition device from National Instrument TM. The gathered data is fed into SW receiver to process Galileo E1 to verify Galileo signal processing by Galileo live signal from GIOVE-A.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.41 no.6 s.324
• /
• pp.1-7
• /
• 2004

The development of direct receiver techniques is expected to be a solution for future wideband or multi-band wireless systems based on software defined radio. In this Paper, we study the regeneration of I and Q signals for the SDR based direct conversion receiver, so that we can handle a wide bandwidth and maintain maximal flexibility in system utilization. After modeling the basic system considering the real wireless communication environment, and studying the impact of imperfect phase imbalance on the performance of a direct conversion receiver, we propose a suboptimal I and Q signal regeneration algorithm for the system. The proposed algerian regenerates I and Q signals using a real time early-late compensator which effectively estimates phase imbalances and gives feedback in a directreceiver. The proposed algorithm is shown to mitigate the impact of AWGN and improves performance especially at low SNR channel condition. According to the computer simulation, the BER performance of the proposed system is at least about 4 dB better than conventional systems under $45{\~}55$ degrees random phase errors.

• Geophysics and Geophysical Exploration
• /
• v.7 no.3
• /
• pp.157-163
• /
• 2004

In this study, a travel-time tomography software was developed under the MS Windows system and GUI environment for user. The software supports following features: (1) supporting various data input format (2) flexible treatment of shot and receiver coordinate coding (3) flexible first arrival picking and modification (4) easy modification of intermediate tomogram. It is expected that the effort of the user can be minimized in each data processing step.

• Proceedings of the KSRS Conference
• /
• 2007.10a
• /
• pp.522-525
• /
• 2007

Frame Synchronization is applied to not only digital data transmission for data synchronization between transmitter and receiver but also data communication with satellite. When satellite image data with high resolution and mass storage is transmitted, hardware frame synchronizer for real-time processing or software frame synchronizer for post-processing is used. In case of hardware, processing with high speed is available but data loss may happen for Search of Frame Synchronization. In case of software, data loss does not happen but speed is relatively slow. In this paper, Pending Buffer concept was proposed to cope with data loss according to processing status of Frame Synchronization. Algorithm to process Frame synchronization with high speed using bit threshold search algorithm with pattern search technique and SIMD is also proposed.