Electronics and Telecommunications Research Institute

Korea Advanced Institute of Science and Technology

Pantech Co., Ltd.

Seog-Ill Song

Hyun-Seo Oh

Hee-Soo Lee

Dan-Keun Sung

Sung-Ho Moon

Jae-Hoon Chung

Jae-Kyun Kwon

Seo-Young Lee

Jae-Sang Cha

Jae-Joon Kim

Ju-Phil Cho

Hyung-Yun Kong

Kang-Soo Shin

Ji-Young Yun

Soo-Mee Park

Su-Won Park

Mun-Geon Kyeong

In-Soo Sohn

Disclosed is a method for increasing a data transfer rate without an increase in the whole bandwidth using intrinsic spreading codes and orthogonal codes. The method uses interleaving, OFDM modulation/demodulation, and maximum likelihood detection (MLD) to overcome the effects of multipath fading or signal interference, determines grouped optimal values by a grouping method of dividing the intrinsic spreading codes in series, and calculates an integrated optimal value for all the intrinsic spreading codes using the grouped optimal values, thereby reducing the complexity of MLD according to the length of the intrinsic spreading code and acquiring an improved performance.

Wireless communication system and method using grouping maximum likelihood detection

This invention is concerned with a transmission control method and apparatus in a collision interval for a collision of multidimensional hopping patterns. In the present invention, each orthogonal wireless resource in the coordinate of the multidimensional orthogonal resource can hop according to the hopping pattern negotiated between a transmitter and a receiver, and each corresponding channel is distinguished by the hopping pattern. A specific multidimensional hopping pattern is allocated to each secondary station. The hopping pattern is either permanently allocated to the secondary stations or temporarily allocated from the primary station during a call set-up. The permanent allocation of the hopping pattern to the secondary stations is achieved when the hopping pattern is identified based on a unique identifier, such as ESN of the secondary station. The hopping patterns of the secondary stations are mutually independent so that the coordinates of the same orthogonal resource is allocated to different secondary stations in a simultaneous manner in a specific moment. Through this invention, in order to improve the performance of the multidimensional resource hopping multiplexing system, refining transmission and perforation mechanisms for the collisions of multidimensional resource hopping patterns can reduce the overall perforation probability.

Digital communication method and system

An apparatus for transmitting and receiving a signal in Code Division Multiple Access/Orthogonal Frequency Division Multiplexing (CDMA/OFDM) system is provided. The apparatus discriminates user signals with a unique spreading code and the orthogonal codes, increases data transmission rate with the non-binary value without increasing of entire bandwidth used by the users, solves signal interference with interleaver and diversity effect of interleaving and OFDM, and maximizes transmission efficiency by varying modulation schemes depending on channel states.

Apparatus for transmitting and receiving signal using orthogonal codes and non-binary values in CDMA/OFDM system and method thereof

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Daejeon, South Korea

Seog-Ill Song