Inha-industry Partnership Institute

TaeKyung Sung

Kyungsup Kwak

SangKyoon Nam

Sunkyung Shin

The present invention relates, in general, to a joint channel and frequency offset estimation apparatus and method based on a multi-band-orthogonal frequency division multiplexing system, and, more particularly, to a joint channel and frequency offset estimation apparatus and method based on an MB-OFDM system, which uses low-rank LMMSE channel estimation, in which a low-rank is applied to the MB-OFDM system, thus decreasing complexity, and adds a simple structure using the autocorrelation characteristics of an estimated channel, thus joining channel estimation to frequency offset estimation at low complexity. The apparatus includes a channel estimator for receiving a Fourier-transformed OFDM signal, and calculating results of channel estimation using a Linear Minimum Mean Square Error (LMMSE) channel estimation, which minimizes a Mean Square Error (MSE) between an actual channel value and an estimated channel value. An autocorrelation unit calculates an autocorrelation value using the results, which are calculated through the channel estimator, in which a frequency offset is considered. A frequency offset estimator calculates a frequency offset, having a maximum value calculated by the autocorrelation unit, and estimating an actual frequency offset.

Joint estimation apparatus of channel and frequency offset based on multiband-orthogonal frequency division multiplexing and thereof

A system for managing service mobility using an extensible Markup Language (XML) electronic signature. A mobility interface stops and stores the operation of a service being currently performed. Before the service is moved, a service serializer serializes service state information and converts it into an XML form which is attachable to an electronic signature. An XML security manager creates an XML electronic signature for the Manifest file of the Java ARchive (JAR) file of a service bundle, attaches the serialized service state information to the XML electronic signature, and records it. A service installer transmits the signed JAR file to an Open Service Gateway initiative (OSGi) framework that has requested that the service be moved.

Growing community of inventors

Incheon, South Korea

TaeKyung Sung