Electronics and Telecommunications Research Institute

Byung-Su Kang

Kwang-Chun Lee

Jae-Ho Jung

Do-Seob Ahn

Heon-Kook Kwon

Bon-Jun Ku

Yang-Su Kim

Seong-Min Kim

Joon-Hyung Kim

Sung-Jun Lee

Jong-Min Park

Gweon-Do Jo

A repeating apparatus in a wireless communication system includes: a signal detection unit configured to receive a signal from a base station or a mobile station and detect strength of the signal; a control unit configured to compare the signal strength detected by the signal detection unit with signal strength predetermined by the system and provide comparison information; and an output signal control unit configured to receive the comparison information from the control unit and adjust and amplify gain of a signal transmitted to the base station or the mobile station.

Repeating apparatus and method in wireless communication system

A gain control apparatus in a receiver of multiband OFDM system includes: an amplifier amplifying a received signal based on a first auto gain control signal; an analog-to-digital converter for converting the amplified signal into a digital signal; band reception signal extractor for extracting a signal of a desired reception band from the converted digital signal for each reception band, and controlling gain of the extracted signal according to a second auto gain control signal; a reception power detector for detecting a reception power value of whole band from the converted digital signal; and a multiband integration baseband processor for generating the first auto gain control signal by using the detected reception power value of the whole band, and generating the second auto gain control signal to be provided to the band reception signal extraction units, resource allocation information for each band and a reception power for each reception band.

Gain control apparatus and method in receiver of multiband OFDM system

The present invention relates to a device for compensating a radio frequency distortion caused by a sample/hold operation of a digital/analog converter in an orthogonal frequency division multiplexing (OFDM) transmission system, and a method thereof. In a digital transmission system, an edge frequency signal of a transmission signal band is distorted by a sample/hold operation of a digital/analog converter such that a signal attenuation is generated at a frequency domain by a sync function having a zero point at a sample frequency of a transmission signal. In the present invention, the signal distortion may be compensated by multiplying a coefficient of an inverse sync function by a signal weight value at the frequency domain, and it may be compensated by using a single multiplier and a lookup table storing the coefficient of the inverse sync function.

Device for compensating radio frequency distortion in orthogonal frequency division multiplexing transmission system and method thereof

The present invention relates to an antenna matching device that varies a frequency bandwidth according to mobile communication services, and to a transceiver having the same. To this end, an exemplary embodiment of the present invention provides a transceiver that varies a frequency band and a bandwidth according to required services in a mobile communication system, the transceiver including an antenna matching controller that generates a prescribed switch control signal according to a service requested by a user, an antenna variable matching unit that variably forms a matching circuit according to the switch control signal to be transmitted from the antenna matching controller and varies the frequency band and the bandwidth, an analog processing unit that processes a signal to be transmitted/received through the antenna variable matching unit, and a wideband antenna that transmits/receives a radio frequency according to the frequency band and the bandwidth set by the antenna variable matching unit. Another exemplary embodiment of the present invention provides an antenna matching device including a resistor that reduces a frequency bandwidth, an inductor that reduces a frequency passing band, a capacitor and a resistor that increase the frequency passing band, and switches that control the operations of the inductor and the capacitor. According to the present invention, unnecessary radiation power of a variable matching unit can be minimized, and maximum transmission power required according to services can be reduced. In addition, system construction costs can be reduced, and a user capacity can be increased.

Antenna matching device and transceiver having the same

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

Byung-Su Kang