Electronics and Telecommunications Research Institute

Gweon-Do Jo

Jae-Ho Jung

Joon-Hyung Kim

Young-Hoon Kim

Kwang-Chun Lee

Jung-Hoon Oh

Jin-Up Kim

Hyung-Jin Kim

Seong-Chul Cho

Seong-Min Kim

Hyun-Kyu Chung

Dae-Sik Kim

Sung-Jun Lee

Heon-Kook Kwon

Sang-Woo Nam

Byung-Su Kang

Hui-Rae Cho

A digital pre-distortion (DPD) power amplifying apparatus and a method for digitally controlling synchronization of the DPD power amplifying apparatus, which includes a power amplifier, a bias shifter and a DPD unit, are provided. The method includes acquiring a DPD path delay time at a path along which an input signal is fed back to the DPD unit; delaying an input signal incoming to the power amplifier by the DPD path delay time and acquiring synchronization by delaying a bias signal a predetermined number of times until the bias signal and the delayed input signal are synchronized with each other; and in response to synchronization between the bias signal and the delayed input signal being established, pre-distorting the input signal according to a feedback signal output from the power amplifier.

Digital pre-distortion power amplifying apparatus and method for digitally controlling synchronization thereof

A distortion compensation apparatus and an apparatus and method for transmitting a signal are provided. The distortion compensation apparatus can extract precise distortion information by adding an additional signal to an input signal during the compensation of distortion in a nonlinear apparatus, and can linearize the nonlinear properties of the nonlinear apparatus using the distortion information. The apparatus for transmitting a signal can output a signal linearized by the same method as that used by the distortion compensation apparatus.

Distortion compensation apparatus and apparatus and method for transmitting signal

The present invention relates to a memory address generating method and a twiddle factor generator using the memory address generating method in a fast Fourier transform (FFT) system. In the memory address generating method for generating a memory address of a twiddle factor in a fast Fourier transform (FFT) system according to an embodiment of the present invention: a) a temporary address value of a second twiddle factor is induced and generated based on a first twiddle factor; b) a control signal for controlling the system is generated based on the generated temporary address value; and c) a memory address value of the second twiddle factor is generated from the temporary address value.

Memory address generating method and twiddle factor generator using the same

Provided are a signal amplifying apparatus and method and a wireless transmitter using the same. The signal amplifier includes a polar coordinate converter configured to output an envelope signal and a phase signal by converting a signal to a polar coordinate, a multilevel quantizer configured to output a multilevel quantized signal by quantizing the envelope signal to multiple levels, an amplification state controller configured to control an amplification state using the multilevel quantized signal, and a power amplifier configured to amplify the phase signal according to the controlled amplification state.

Apparatus and method for amplifying signal and wireless transmitter using the same

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 controlling a power level to control contention between mobile terminals in an uplink contention period in an orthogonal frequency division multiplexing access (OFDMA) system, and a method thereof. In the method, cell broadcasting information broadcasted from the base station is received by the mobile terminal, the transmission power information of the base station is obtained from the cell broadcasting information by the mobile terminal, a received power level of the received cell broadcasting information is obtained by the mobile terminal, transmission power of a signal transmitted to the base station is determined based on the transmission power information and the received power level, and the signal is transmitted to a contention period based on the determined transmission power.

Method for controlling signal power level to control contention beween mobile terminals, and signal power level controller in orthogonal frequency division multiplexing system

A pre-distortion apparatus of a power amplifier includes: a pre-distortion unit configured to generate a pre-distorted signal of an input signal by calculating a magnitude of the input signal and outputting a complex correction coefficient corresponding to the calculated magnitude of the input signal, and provide the generated pre-distorted signal as an input of the power amplifier; and a complex correct coefficient update unit configured to generate an error signal by comparing an output signal of the power amplifier with the input signal and updating the complex correction coefficient to minimize a magnitude of the generated error signal, wherein the pre-distortion unit provides a constant bias value corresponding to the magnitude of the input signal as a bias of the power amplifier while updating the complex correction coefficient.

Pre-distortion apparatus of power amplifier and method thereof

An encoding system using a non-binary turbo code and an encoding method thereof is capable of encoding an input signal at a low code rate and at once by spreading the input signal. An input information bit sequence is spread according to the obtained channel code rate and outputting the same in the form of one pair of input sequences, the pair of input sequences is encoded, and a parity bit sequence is generated and an encoded data sequence is generated by multiplexing the parity bit sequence.

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Daejeon, South Korea

Gweon-Do Jo