Electronics and Telecommunications Research Institute

Other

Power Carbon Technology Co., Ltd.

Taehyun Jeon

Sok-Kyu Lee

Eun-Young Choi

Myung-Soon Kim

Deuk-Su Lyu

Hee-Jung Yu

Heejung Yu

Jae-Young Ahn

Yong-Hoon Lee

Young-Doo Kim

Jihoon Choi

Inhyoung Kim

Woo-Yong Lee

Hyoung-Soo Lim

Ung Ju Lee

Do Young Seung

Sang Ick Lee

Joung-Doo Kim

In the present invention, data generated from a source unit are distributed to at least one bandwidth; the data distributed to the respective bandwidths are encoded in order to perform an error correction; the encoded data are distributed to at least one antenna; a subcarrier is allocated to the data distributed to the respective antennas, and an inverse Fourier transform is performed; a short preamble and a first long preamble corresponding to the subcarrier are generated; a signal symbol is generated according to a data transmit mode; and a frame is generated by adding a second long preamble between the signal symbol and a data field for the purpose of estimating a channel of a subcarrier which is not used.

Apparatus for transmitting and receiving data to provide high-speed data communication and method thereof

An apparatus for adaptively modulating/demodulating signals in a multi-input multi-output (MIMO) system having a layered time-space architecture detector and a method thereof is disclosed. The apparatus includes: a bit and power allocation information calculator for deciding an equivalent channel gain in a reverse order of Vertical-Bell laboratories Space Time (V-BLAST) based on MIMO channel information feedbacked from a receiver and determining the number of bits and transmission power to be transmitted to each transmitting antenna by using the equivalent channel gain; and adaptive modulation means for modulating signal of each layer with corresponding modulation method based on the determined number of bits and transmitting power, controlling the transmitting power and transmitting the adaptively modulated signal through each transmitting antenna. The present invention can improve performance without increase of implementation complexity and easily expand to MIMO-OFDM system by adaptively modulating and demodulating signals in reverse order of conventional V-BLAST detection method.

Apparatus and method for adaptively modulating signal by using layered time-space detector used in MIMO system

An error tracking apparatus and method for tracking a residual frequency error, a phase error, a timing error, and a signal amplitude variation to enhance a phase error tracking performance and a tracking speed in an orthogonal frequency division multiplexing (OFDM) system is provided. The error tracking apparatus and method include: a frequency error corrector for correcting a frequency at a time domain by adding a tracking carrier error estimating value to an initial carrier frequency error estimating value; a signal amplitude tracking corrector for controlling a signal amplitude by multiplying an input signal converted by a fast Fourier transform (FFT) by an output value corresponding to a calculated power of a receive pilot signal; a channel corrector for outputting a channel correcting signal by multiplying the receive pilot signal by a complex conjugate of a frequency channel response of the receive pilot signal; a carrier frequency error estimator for estimating a carrier frequency error parameter using the channel-corrected pilot and providing the tracking carrier frequency error estimating value; a time offset estimator for estimating a time offset parameter using the channel-corrected pilot; and a carrier phase error estimator for estimating a carrier phase error parameter using the channel-corrected pilot.

Residual frequency, phase, timing offset and signal amplitude variation tracking apparatus and methods for OFDM systems

The present invention relates to a method for detecting a signal in an MIMO system. In the method, a received signal is detected in a zero forcing (ZF) method, and a first detection interval is established from the signal detected in the ZF method. The received signal is detected within the first detection interval in a maximum likelihood (ML) method, a second detection interval is established from the signals respectively detected in the ZF method and the ML method. A final solution is determined by detecting the received signal within the second detection interval in the ML method.

Method for detecting signal in multiple input multiple output system and receiving device of multiple input multiple output system

Disclosed is a link margin adaptation method using feedback information of a wireless communication system. For transmission and reception of data between two nodes of the wireless communication system, a transmission node requests a receiving node to transmit a link margin. The transmission node receives the link margin, and selects one of a white noise table or a delay spread table according to a delay spread value between the two nodes. Then, the transmission node adapts a link between the two nodes to a transmission mode and decides a transmission rate to transmit data at the decided transmission rate, thereby improving transmission capacity of the wireless communication system, obtaining the optimum link state, extending power utilization time of stations, and reducing interference between stations.

Link adaptation method using feedback information for wireless communication system

An apparatus for detecting symbol synchronization in a received signal including a first preamble and a second preamble which is consecutive to the first preamble, the apparatus including a first correlator calculating a first correlation value between the received signal and a first pattern of a first period among iterative patterns of the first preamble, a second correlator calculating a second correlation value between the received signal and a second pattern of a second period among iterative patterns of the second preamble, a third correlator calculating a third correlation value between the first correlation value and the second correlation value, and a detector detecting symbol synchronization from the third correlation value.

Method for detecting symbol synchronization and apparatus thereof

Apparatus and method for adaptively modulating signal by using layered time-space detector used in mimo system

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Sungnam, South Korea

Taehyun Jeon