Youngsun Kim

Closed-Form Expression of Nakagami-Like Background Noise in Power-Line Channel

A closed-form expression for the real part of background noise is derived for the power-line channel modeled by Nakagami probability density function. Simulation with various parameters shows the derived expressions validity. The closed-form expression can be of benefit to communication system designers in that it facilitates the design of optimum receiver and its performance evaluation.

A Systematic Approach to Analyzing Multipath Parameters From PLC Channel Response

The reliable analysis of the power-line communication (PLC) channels is necessary to model, design, and implement a well-matched PLC transceiver. However, a typical power-line channel has not yet been properly described since it is difficult to analyze the time- and space-varying characteristics. Consequently, it is still very important to measure, analyze, and model the power-line channel well. In this paper, focusing on the analysis of the channel response, we suggest a novel systematic approach to analyzing the multipath parameters. The proposed approach is convenient in that we can systematically find the multipath parameters like time delays and attenuation factors including magnitudes and phases from the measured complex impulse response. The simulation and experimental results show that the proposed approach is valid and appropriate for a typical power-line channel.

Two-Dimensional Navigation Error for Geometry of Landmark in Line-Of-Sight Measurement Based Vision Navigation System

Geometric effect of landmarks to the navigation error is investigated in the two-dimensional line-of-sight measurement based vision navigation system. DOP is derived between line-of-sight measurement error and navigation solution error. For cases of three landmarks in an area, variations of the DOP were observed through computer simulations. Vision navigation system experiments were performed for the cases. Simulation and experimental results show that navigation solution errors have similar trend to DOP values of the simulation.

Design of Analog Front End for Power-Line Communication of Korean Standard

In this paper, we present the design of the analog front end (AFE) module for power-line communication (PLC) which complies with the Korean industrial standard (KS) specifications. We measured the electromagnetic emission of the implemented AFE and verified that the measurement satisfies the regulation for PLC.

Study on Very High-Rate Power Line Communications for Smart Grid

In this paper, we study on the reliability of Very High-rate Power Line Communication (VH-PLC) for Smart Grid, so that the resultant data rate is over 400Mbps at a physical layer. Firstly, reviewing the research trend of the PLC, we discuss the required techniques for supporting the Smart Grid. Considering a pre-specification with the value of several parameters, we investigate a multi-carrier modulation technique to overcome limitations of higher rate transmission under power line channel environments. Then, we propose a system specification of the VH-PLC in the sense of enhancing two features. One is resolving the problem of the co-existence of the deployed high-speed PLC according to the published standardization of KS X 4600-1 in Korea. The other is getting better performance on the grid adopting the diverse element techniques, such as multi-carrier modulation, a subcarrier utilization mode, a variable rate LDPC (Low Density Parity Check) code, and a time and frequency diversity technique. Further, a simulation tool, composed of an Event-Driven simulator and a Time-Driven simulator, is developed for the purpose of verifying the system performance and continuously cross-checking the test bench signal of the proposed VH-PLC system.

Implementation and Performance Analysis of Noncoherent UWB Transceiver Under LOS Residential Channel Environment

This paper focuses on two things. One is to describe implementation of a Low-Rate Ultra-Wideband (LR-UWB) transceiver for low power Wireless Personal Area Network (WPAN) applications. The other is to derive the Bit Error Rate (BER) performance of the proposed system. At first, in order to implement low-power and low-complexity transceiver, we design a non-coherent On-Off-Keying(OOK) UWB system by adopting the architecture of the simplified asynchronous transmission and the edge-triggered pulse transmission, which makes the system performance independent of the shape of the transmitted waveform, robust to multipath channels. The designed non-coherent UWB transceiver architecture has an advantage of the simple realization since any mixer, high-speed correlator, and very high-sampling A/D converter are not necessary at the cost of performance degradation of about 3dB. Further, the designed non-coherent UWB transceiver is actually implemented with the wireless CANVAS prototyping testbed in short range indoor application environment such as a lecture room. The implemented prototype testbed is proven to offer the data rate of 9.6kbps and 115kbps on the conditions of Peer-to-Peer (P-to-P) in the indoor channel within the range of about 10m. At second, we analyze the bit error rate (BER) performance of this proposed system under the line-of-sight (LOS) residential channel environment. As a result, it is necessary to choose appropriate number of Window Bank(WB)s for better BER performance.