Samsung Electronics Co., Ltd.

University of Texas System

Seoul National University

Inha-industry Partnership Institute

Pandharipande Ashish

Ho-Jin Kim

Ho Rim Yang

Hyoung-Woon Park

Jae-Hak Chung

Duck-Dong Hwang

Sang-Jo Yoo

Jae-Myeong Kim

Ju-Ho Lee

Sung-Jin Kim

Antonio Forenza

Young-Ho Jung

Kwang-Bok Lee

Robert W Heath

Kyoung-Jin Cho

Chang-Gun Seo

Marios Kountouris

An apparatus and method for signal detection in a CR-based wireless communication system are provided. In the signal detection apparatus, a cyclic power calculator calculates the power spectral density of a cyclo-stationary and periodical signal to be detected with respect to a cyclic frequency and calculates optimum statistics using the power spectral density. A signal detector determines whether a signal exists or not according to the optimum statistics.

Apparatus and method for signal detection in a cognitive radio-based wireless communication system

A communication initialization method at a MAC layer in a CR wireless communication system is provided. The use or non-use of a frequency band is sensed over a broadband with a minimized sensing time in a non-interfering manner with existing communication systems.

Communication initialization method at medium access control layer in a cognitive radio wireless communication system

A method of partitioning resources in a CR wireless communication system and a system supporting the same are provided. A new BS receives radio resource status information from a prior BS using a particular frequency band, and requests resource partitioning to the prior BS using a new uplink subchannel defined for communications between BSs. Resource negotiation messages are exchanged over a channel defined between the two BSs so as to efficiently partition resources between the BSs.

Method of partitioning resources in a cognitive radio wireless communication system and system supporting the same

Disclosed are an analog-to-digital conversion method and apparatus capable of reducing quantization distortion in a receiver supporting multi-standard radios for which digital signal processing must be differently performed. The analog-to-digital conversion apparatus includes a first filter for filtering an input analog signal into a plurality of sub-band signals, a down-sampler for down-sampling the sub-band signals, a sub-band processor for allocating quantization bits for the sub-band signals, respectively, and digitizing the sub-band signals by using the allocated quantization bits, an up-sampler for up-sampling the digitized sub-band signals, and a second filter for reconstructing the sub-band signals into one digital signal. Multi-standard radio signals can be processed into digital signals in a receiver to which SDR is applied, and quantization distortion can be reduced during a procedure of converting the radio signal into the digital signal.

Method and apparatus for performing analog-to-digital conversion in receiver supporting software defined multi-standard radios

A multiple-input multiple-output (MIMO) wireless communication system. A transmitter that includes a plurality of transmit antennas selects one of a spatial multiplexing scheme and a spatial diversity scheme, processes a signal in the selected transmission scheme, and transmits the signal through the plurality of transmit antennas. A receiver that includes a plurality of receive antennas processes a signal in a reception scheme mapped to a transmission scheme of the transmitter. The transmission schemes include a transmission scheme for maximizing diversity gain and a transmission scheme for maximizing spectral efficiency. The MIMO communication system using an adaptive transmission mode switching technique performs switching between MIMO transmission modes using spatial selectivity of a channel, thereby obtaining maximum gain in a signal to noise ratio (SNR) and spectral efficiency according to channel state.

MIMO communication system using an adaptive transmission mode switching technique

A bit/power loading method in an adaptive modulation-based multicarrier communication system computes ratios of modulation mode values to transmission power values sub-channel-by-sub-channel, selects a combination of sub-channels in which a sum of the ratios is maximized for a total number of bits to be simultaneously transmitted, and transmits signals in modulation modes corresponding to ratios of modulation mode values to transmission power values associated with the selected sub-channels. Because the bit/power loading method selects a combination of sub-channel modulation modes with the minimum total transmission power for a given number of bits on the basis of transmission power in each sub-channel modulation mode, the bits can be transmitted at the minimum transmission power in a given environment.

Adaptive bit/power loading technique for a multicarrier communication system

An apparatus and method for performing beamforming or transmitting a plurality of bit streams output through Adaptive Modulation and Coding (AMC) via a plurality of transmission antennas in a base station using a multi-antenna scheme. The apparatus and method include classifying the plurality of transmission antennas into a plurality of transmission antenna groups; selecting one of the transmission antenna groups depending on a group selection signal being fed back from a mobile station; and outputting each of the bit streams to its associated transmission antenna among the transmission antennas constituting the selected transmission antenna group.

Apparatus and method for beamforming in a multi-antenna system

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Yongin-si, South Korea

Pandharipande Ashish