Electronics and Telecommunications Research Institute

Industrial Cooperation Foundation Chonbuk National University

Bon-Jun Ku

Do-Seob Ahn

Byung-Su Kang

Hee-Wook Kim

Yang-Su Kim

Kun-Seok Kang

Ho-Jin Lee

Jong-Min Park

Soo-Young Kim

Tae-Chul Hong

Seung-Hyun Nam

A transmission apparatus and method for implementing frequency selectivity in a multi-beam satellite system that transmits a signal to user equipment through one or more antenna feed groups. The transmission apparatus includes: an antenna feed group selecting unit configured to select one or more antenna feed groups from the one or more antenna feed groups; a cyclic delay offset determining unit configured to determine a cyclic delay offset according to a determination result of the antenna feed group selecting unit; and a transmitting unit configured to apply the cyclic delay offset determined by the cyclic delay offset determining unit to a signal to be transmitted through the one or more antenna feed groups selected by the antenna feed group selecting unit, and to transmit a resultant signal.

Apparatus and method for providing frequency selectively in satellite communication system

Disclosed are an apparatus and a method for normally receiving data by accurately estimating and compensating for a frequency offset for a wireless frequency channel through which data are transmitted in a communication system under wireless frequency environment. In the present invention, data transmitted through the wireless frequency channel are received, the frequency offset in the wireless frequency channel from the receive data is estimated based on an interpolation scheme using the periodogram, and the frequency offset is compensated to receive the data by frequency-synchronizing with the wireless frequency channel.

Apparatus and method for receiving data in communication system

A signal processing technology for allowing a repeater to transmit a signal received from an external apparatus to a terminal is provided. In a satellite system, a signal transmitted from a satellite or transmitted to a satellite is subject to a low order modulation, and a terrestrial repeater performs a high order modulation on signals and retransmits the signals.

Signal processing method for terrestrial repeater

Provided is a device for tracking polarizations. A receiving polarization tracking device includes a feeder for finding vertical and horizontal vector components by receiving vertical and horizontal polarizations, a polarization estimator for estimating distortion of polarizations using the vertical and horizontal vector components outputted from the feeder, a polarization controller for controlling amplitudes and phases of vertical and horizontal polarizations based on information about the estimated distortion from the polarization estimator and an output signal from the receiving polarization tracking device, and a combiner for combining the vertical and horizontal polarizations controlled from the polarization controller.

Device for tracking polarization

Provided is a device for shaping a flat-topped element pattern using a circular polarization microstrip patch. The device includes: a microstrip patch feeding unit for generating circularly polarized signals of a basic mode; a circular waveguide for guiding the circular polarized signals and generating signals of high-order modes; and a pattern shaping unit for shaping FTEP through an electromagnetic mutual coupling between the signals of the high-order modes generated from the pattern shaping unit.

Device for shaping flat-topped element pattern using circular polarization microstrip patch

Provided is an antenna control apparatus for controlling an antenna mounted on a stratospheric platform of the stratospheric communication system. The apparatus includes a plurality of location signal receivers, each receiver being positioned at each of predefined different points of the stratospheric platform and receiving a location signal for the stratospheric platform, a calculating circuit for calculating an adjustable displacement for the antenna, and an antenna driver for adjusting a direction of the antenna. The calculating circuit calculates a location and attitude of the stratospheric platform based on the location signals, and then computes the adjustable displacement using the location and attitude information. This invention can reduce power consumption in the stratospheric platform and recovery time of directional point of the beam.

Apparatus for controlling antenna in stratospheric platform and stratospheric platform system having the same

A hexagonal array structure of a dielectric rod for shaping a flat-topped element pattern (FTEP) is provided. The hexagonal structure of dielectric rods forming a flat-topped element pattern (FTEP) includes: a center element for forming a unit radiation pattern of the FTEP through an electromagnetic wave mutual coupling by receiving a polarization signal of a basic mode; a plurality of first ring elements arranged at vertexes of a regular hexagon based on the center element for forming the unit radiation pattern by electromagnetic wave mutual coupling with the center element and an electromagnetic wave; and a circular waveguide array supporting unit for supporting the center element and the plurality of first ring elements.

Growing community of inventors

Daejon, South Korea

Bon-Jun Ku