Showing papers by "Minho Cheong published in 2008"

Multi-dimensional detector for receiver of mimo system

Abstract: Provided are a multi-dimensional detector for a receiver of an MIMO system and a method thereof. The multi-dimensional detector includes a first symbol detecting unit for calculating symbol distance values using an upper triangular matrix (R) obtained from QR decomposition to detect an m th symbol; a symbol deciding unit for deciding a symbol having a minimum distance value among the calculated symbol distance values from the first symbol detecting unit; and a second symbol detecting unit for calculating symbol distance values using an updated received signal y and the upper triangular matrix R to detect a (m−1) th symbol.

Apparatus and method for channel estimation in MIMO systems

Abstract: Provided are a preamble structure and a channel estimation algorithm thereof. A communication method for a transmitter for channel estimation in a Multiple Input Multiple Output (MIMO) wireless communication system having N receiving antennas, includes generating a preamble interval having a short training field that includes a predetermined pattern iterated N times on a time domain and is used for compensating for a carrier frequency offset, and transmitting a packet having the preamble interval.

Transmitter and receiver for high throughput wireless communication system using multiple antenna, method thereof, and digital intermediate frequency transmission signal processing method for the same

Abstract: Provided are a transmitter and receiver for a high throughput wireless communication system using a multiple antenna, a method thereof, and a digital intermediate frequency (DIF) transmission signal processing method for the same. The transmitter, includes: a baseband transmitting unit for processing a transmission signal by performing a Media Access Control (MAC) protocol process on transmission data and dividing the transmission data into n band signals where n is a predetermined natural number in a physical layer process; a DIF transmitting unit for integrating transmission signals of each band transmitted from the baseband transmitting unit and outputting m channels where m is a predetermined natural number; and a Radio Frequency (RF) transmitting unit for modulating each channel signal transmitted from the DIF transmitting unit into an RF signal and emitting the signal through the multiple antenna.

Method for producing parity check matrix for low complexity and high speed decoding, and apparatus and method for coding low density parity check code using the same

Abstract: Provided are a method for producing a parity check matrix for low complexity and high speed decoding, and an apparatus and method for coding a Low Density Parity Check (LDPC) code using the same. The method includes: calculating a cyclic shift value of a subblock to a matrix; and when the calculated cyclic shift values of the subblock are arrayed in the matrix, producing a parity check matrix by arraying the cyclic shift values of the subblock except ‘0 matrix’ without duplication to any one column.

Mimo antenna receiving apparatus and receiving method

Abstract: Provided is a reception apparatus and method of a Multiple Input Multiple Output (MIMO) system that receives a plurality of different data streams in a multiple cell environment. The reception apparatus for receiving a plurality of different data streams in a multiple input multiple output (MIMO) antenna system includes a data stream detector for detecting each data stream by removing interference between the different data streams while maintaining channel information; and a cochannel interference (CCI) remover for removing cochannel interference from each data stream detected in the data stream detector. The present invention can remove cochannel interference and increase channel capacity to thereby acquire both diversity gain and multiplexing gain.

QR decomposition apparatus and method for MIMO system

Abstract: Provided is a QR decomposition apparatus and method that can reduce the number of computers by sharing hardware in an MIMO system employing OFDM technology to simplify a structure of hardware. The QR decomposition apparatus includes a norm multiplier for calculating a norm; a Q column multiplier for calculating a column value of a unitary Q matrix to thereby produce a Q matrix vector; a first storage for storing the Q matrix vector calculated in the Q column multiplier; an R row multiplier for calculating a value of an upper triangular R matrix by multiplying the Q matrix vector by a reception signal vector; and a Q update multiplier for receiving the reception signal vector and an output of the R row multiplier, calculating an Q update value through an accumulation operation, and providing the Q update value to the Q column multiplier to calculate a next Q matrix vector.

Link adaptation method and apparatus in wireless communication system

Abstract: Provided is a link adaptation method and apparatus in wireless communication system. The method, includes: amplifying a received signal; converting the amplified signal into a digital signal; calculating digital signal strength; and calculating the received signal strength based on the digital signal strength and a gain of said amplifying a received signal.

Apparatus and method for detecting reception signal symbol synchronization in wireless communication system

Abstract: Provided is an apparatus and method for detecting reception signal symbol synchronization in a wireless communication system. The method, includes: calculating a channel power value in each of multiple antennas; selecting and averaging at least 2 channel power values; compensating carrier frequency offset for an average value; and determining a symbol boundary of a reception signal according to the size of the average value compensating the carrier frequency offset.

Transmitter and receiver for giga-bps high-throughput wireless communication system with multiple antennas and multiple bands

Abstract: Provided is a transmitter and a receiver for a high-throughput wireless communication system. The transmitter includes a baseband transmitter, a DIF transmitter, and a RF transmitter. The baseband transmitter performs a MAC protocol process on transmission signals and reception signals and processes the transmission signals by dividing an entire transmission band into n bands in a physical layer process of the transmission data, where n is a natural number. The DIF transmitter combines transmission signals of each band from the baseband transmitter and outputs m channel signals corresponding to a number of transmission antennas, where m is a natural number. The RF transmitter modulates each of the channel signals transferred from the DIF transmitter and transmits the modulated signals through m antennas.

Method and apparatus for receiving signal for mimo system

Abstract: Provided is a method and apparatus for receiving a signal for a MIMO system. The receiving apparatus includes: a QR decomposer for calculating a unitary matrix Q, an upper triangle matrix R, and a vector size for a received signal; a multiple dimension detector for calculating a first LLR for an output of the QR decomposer through multiple dimension detection; an inverse matrix and weight calculator for calculating an inverse matrix for the upper triangle matrix R and a weight; an interference remover for regenerating a symbol for a demodulated data stream using the fist LLR and removing interference from an output vector of the QR decomposer using the regenerated symbol; and a weight zero forcing unit for performing zero forcing on the interference removed output vector from the interference remover using the inverse matrix of the upper triangle matrix R and the weight and calculating a second LLR.

Mimo receiver, qr decomposition and multi-dimensional detection used in the mimo receiver

Abstract: Provided are a receiver of a Multiple Input Multiple Output (MIMO) system, QR decomposition and multi-dimensional detection used in the receiver. The receiver includes: a QR decomposing unit for performing a QR decomposing operation in cycles 1 to n T -n−1, and performing a column exchanging operation in cycles n T -n to n T as QR decomposition where n and T are an integer number; and a multi-dimensional detecting unit for receiving a first R matrix R y and a second R matrix R z from the QR decomposing unit, calculating a first distance value for detecting an m th symbol for the first R matrix and a second distance value for detecting an m th symbol for the second R matrix, and simultaneously detecting an m th symbol and an (m−1) th symbol using the first distance value and the second distance value.

Apparatus and method for transmitting data using multi-antenna

Abstract: Provided are an apparatus and method for transmitting data using a multi-antenna. The apparatus includes a transmission buffer selecting unit for selecting transmission buffer of an antenna group corresponding to characteristics of each aggregated Medium access control Protocol Data Units (MPDU) when a list of aggregated MPDUs to transmit is received; a data transmitting unit for generating a list of aggregated MPDUs to transmit with storage information of the aggregated MPDUs, transferring the generated list to the transmission buffer selecting unit and transmitting corresponding aggregated MPDUs through the selected transmission buffer; and a timing controlling unit for controlling a transmission timing of each aggregated MPDU.