Electronics and Telecommunications Research Institute

Samsung Electronics Co., Ltd.

Kt Corporation

Sk Telecom Company, Ltd.

Hanaro Telecom., Inc.

Yonsei University

Ktfreetel Co., Ltd

Choong-Il Yeh

Dong-Seung Kwon

In-Kyeong Choi

Hyoung-Soo Lim

Young-Seog Song

Yu-Ro Lee

Jong-Ee Oh

Kwang-Jae Lim

Chung-Yong Lee

Seung-Ku Hwang

Seong-Rag Kim

Seung-Joon Lee

Chul-Sik Yoon

Jee-Hwan Ahn

Seong-Keun Oh

Myeong-Cheol Shin

Jae-Joon Park

Ji-Won Kang

Moon-Il Lee

Dong-Sung Kwon

The present invention relates to an uplink control channel configuration in a mobile wideband wireless access system, and an allocation method thereof. An uplink control channel includes a long cyclic prefix used to improve interference and distortion caused by multipath transmission characteristics of an initial ranging or handover ranging signal and a periodic ranging or band request ranging signal. In addition, a short orthogonal frequency division multiple (OFDM) symbol is used to transmit uplink control information when one terminal exists or the number of terminals is small.

Structure and construction method of uplink control channel in mobile wideband wireless access system

The present invention relates to a method of forming a random beam, and a beam forming apparatus. A quantization preprocessor and a random unitary matrix having a predetermined pattern are used to form a beam on a mobile terminal. A base station forms a beam using a codeword index of a quantization codebook received from a mobile terminal and channel quality information corresponding to the codeword index, and the mobile terminal generates the codeword index and the channel quality information using pilot signals generated by the base station. The number of pilot signals is equal to the number of transmitting antennas. Therefore, a codebook that has been known to both the mobile terminal and the base station is used, and the mobile terminal can select the codeword index for quantization, which makes it possible to selectively give diversity and thus improve the system efficiency.

Beam forming method and apparatus

The present invention relates to a multi-input multi-output (MIMO) system for enhancing transmission performance. The MIMO system uses space-time encoding and transmit antenna selection methods, and includes a transmitter () and a receiver (). The transmitter () includes N transmit antennas (--) that are more than M transmit antennas (--) used for transmitting a signal to space channel, selects the M transmit antennas (--) among the N transmit antennas (--), and transmits symbol by space-time encoding the symbol. The receiver () includes M receive antenna (--) for receiving a signal from the space channel, detects an information symbol by using the signal received through the receive antenna (--), generates transmit antenna selection information for selecting M transmit antennas (--) among transmit antennas (i--) with reference to a channel estimate, and returns the information to the transmitter.

Multi-input multi-output system for enhancing transmission performance

The present invention relates to a maximum ratio combining method of spatial-filtered received signals and an apparatus using the same. For this purpose the present invention provides a method for receiving signals by using a plurality of antennas that form a linear array antenna, multiplying a plurality of weight vectors by the received signals, summing the multiplication results for each weight vector, and combining the summing results by using maximum ratio combining. According to the present invention, signals are dividedly received by applying spatial filtering for a receiving direction of each signal and performance can be improved by combining the received signals by using maximum ratio combining. In addition, performance of an MRC-rake and a beam forming gain can be simultaneously acquired according to the present invention.

Method for maximal ratio combining of spatially filtered signals and apparatus therefor

The present invention relates to a system for selecting a switched beam for supplying a maximum received power to a subscriber station, and a method thereof. The number of switched beams used by a base station is limited, and a weight value vector for forming the switched beam is predefined. The subscriber station uses a pilot signal for discerning transmitting antennas to estimate channel values for the respective transmitting antennas, and uses the channel values and the predefined weight value vectors to determine a switched beam for supplying a maximum signal-to-noise ratio (SNR). The subscriber station notifies the base station of an identifier of a selected beam by using a feedback channel, and the base station uses the switched beam to transmit traffic data.

Method for selecting switched beam using pilot signal and system thereof

A space-time code used for a transmitter to transmit a plurality of data symbols to a receiver in a MIMO system, the space-time code including a code word matrix for transmitting an amount of data symbols corresponding to a product of the number of transmit antennas and a spatial multiplexing rate during one block period, wherein a row index indicates combined signals transmitted through different transmit antennas and a column index indicates time slots that correspond to the number of transmit antennas, and wherein the number of data symbols allocated to each transmit antenna in a code block corresponds to the spatial multiplexing rate, and the data symbols are combined by different combining coefficients for each transmit antenna at every time slot, and simultaneously transmitted through different transmit antennas, and each transmit antenna transmits a different set of data symbols at every time slot.

Structured space-time code achieving the full diversity and full rate and generating method thereof, and multi-input multi-output system

An apparatus for estimating a RSSI of a signal transmitted/received in a wireless network, the apparatus including an ADC quantizing one of I-branch and Q-branch signals, extracted from the signal, into a digital signal; an absolute value calculating unit calculating an absolute value of the digital signal quantized by the ADC and outputting a result; an accumulate unit accumulating an output of the absolute calculating unit for a given time period and outputting a result; a square unit squaring an output of the accumulate unit and outputting a result; and a multiply unit multiplying an output of the square unit by a given value and outputting a result, the given value being determined based on the number of input bits, an input clip level, and input resistance of the ADC when the probability density functions at input and output signals of the ADC are approximately Gaussian with zero mean.

Apparatus and method for measuring received signal strength indicator, and recording medium storing program embodying the same method

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Daejeon, South Korea

Choong-Il Yeh