Samsung Electronics Co., Ltd.

Ki-Hwan Hwang

Jae-Hyok Lee

Sung-Kwon Jo

Yoo-Seung Song

Seung-Hwan Lee

Seung-Joo Maeng

Jae-Ho Jeon

Myung-Kwang Byun

Ji-Ho Jang

Kyun-Byoung Ko

Myong-Hee Park

An apparatus and method for rate control in a wireless communication system are provided. The apparatus includes a preprocessor, a rate controller, a determiner, and a transmitter. The preprocessor determines feedback information on a physical layer packet using a feedback message of MAC ARQ. The rate controller updates a CQI reported from a receiver using the determined feedback information. The determiner determines an MCS using the updated CQI. The transmitter transmits data using the determined MCS.

Apparatus and method for rate control in a broadband wireless communication system

An apparatus and a method for simultaneously supporting Multiple-Input Multiple-Output (MIMO) and beamforming in a wireless communication system are provided. In the method, two data streams are mapped to each of all of 2N transmission antennas; the two data streams are multiplied by different Cyclic Delay Diversity (CDD) phase sequences; the two data streams multiplied by the different CDD phase sequences for each transmission antenna are added; and the added data stream is multiplied by a beamforming coefficient and transmitted for each transmission antenna.

Apparatus and method for supporting multiple-input multiple-output and beamforming simultaneously in wireless communication system

Provided is an apparatus and method for compensating a timing offset in a broadband wireless communication system. A receiving apparatus for the timing offset compensation includes a selector, a first calculator, and a second calculator. The selector groups two or more adjacent tiles into one or more tile groups and selects one or more pilot pairs, each including adjacent pilot signals, from each tile group. The first calculator calculates an average phase difference between the pilot pairs. The second calculator calculates a timing offset using the average phase difference.

Apparatus and method for compensating timing offset in broadband wireless communication system

A digital predistortion apparatus is provided for predistorting a nonlinear characteristic caused by a wideband power amplifier that amplifies a input signal. The digital predistortion apparatus includes a predistorter, connected to the power amplifier via a digital-to-analog converter (DAC) and a frequency up-converter, for receiving the input signal and compensating for the nonlinear characteristic using a look-up table that depends upon a change in output power of the power amplifier. The digital predistortion apparatus further includes look-up table (LUT) updating block for adaptively updating the look-up table by comparing a feedback signal output from the power amplifier, connected thereto via an analog-to-digital converter (ADC), with the input signal output from the predistorter.

Digital predistortion apparatus and method in power amplifier

A method and apparatus for estimating a signal delay between a transmission signal which is to be processed in a predetermined communication device of a mobile communication system, and a feedback signal. Each of the transmission and feedback signals is sampled for a predetermined length, and signal power magnitude values are computed in a sample unit and are stored in first and second memory blocks. Mean squared error (MSE) values are computed from a plurality of samples, while a start sample position of one block is shifted on a basis of a start sample position of the other block. A sample delay value is estimated from a start sample position of the one block with a smallest MSE value such that a sample delay between a transmission signal and a feedback signal is closely estimated regardless of a frequency allocation (FA) value.

Method and apparatus for estimating a sample delay between a transmission signal and a feedback signal in a mobile communication system, and a base station transmitter using the same

An apparatus and method for eliminating the spurious signal of a non-linear amplifier in a base station transmitter of a mobile communication system are provided. A digital predistorter includes first and second predistorters, each having a memoryless non-linearity part using a look-up table and a memory non-linearity part using an finite impulse response (FIR) filter. The first predistorter adaptively updates the look-up tables, while the second predistorter adaptively updates the filtering coefficients of the FIR filters. According to another embodiment of the present invention, a digital predistorter has a memoryless non-linearity part using a look-up table and a memory non-linearity part using an FIR filter, and adaptively updates the look-up table and the filtering coefficients of the FIR filter.

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Seoul, South Korea

Ki-Hwan Hwang