摘要:
Provided are a receiving apparatus for a multiple input multiple output (MIMO) system and a method thereof. The receiving apparatus includes a QR decomposing unit for calculating a single (Q) matrix vector and an upper triangle (R) matrix vector for a receiving signal vector; a first symbol estimation unit for estimating predetermined symbols using the calculated Q matrix vector and R matrix vector; a log likelihood ratio (LLR) calculating unit for calculating log likelihood ratios of unit bits for the estimated symbols; an interference removing unit for receiving a decoded signal that is decided using the calculated log likelihood ratios and removing interference from the receiving signal vector; and a second symbol estimation unit for linearly estimating remaining symbols for the interference removed signal.
摘要:
Disclosed are an apparatus and a method for transmitting/receiving data while providing power saving efficiency of a terminal, for example, a station (hereinafter, referred to as ‘STAS) in a communication system providing services to multi users in a multi-input multi-output (hereinafter, referred to as ‘MIMO’) scheme. The apparatus for transmitting data includes: a receiving unit configured to receive an uplink frame from a plurality of terminals by a multi user-multiple-input multiple-output (MIMO) scheme; a generating unit configured to generate a packet including support information on a multi user-power saving scheme with the terminals; a buffering unit configured to buffer data corresponding to the terminals; and a transmitting unit configured to transmit a downlink frame including the generated packet and the buffered data to the terminals by the multi user-MIMO scheme.
摘要:
Disclosed is a media access control apparatus and method in a wireless local area network (LAN) system, which improves the performance of a wireless network by obtaining a transmission opportunity based on information on a station (STA), received from an access point (AP) in a contention-based distributed media access control system such as an IEEE 802.11 wireless LAN system. In the media access control apparatus and method, a station determines a contention window (CW) value based on information on other stations accessing a same access point and information on the idle state of a channel, so that an inefficient CW value is be set in a Distributed Coordination Function (DCF) used in the IEEE 802.11. Accordingly, it is possible to increase the processing speed of the station and to the efficiency of a wireless LAN network.
摘要:
A high-speed quasi-cyclic low density parity check (QC-LDPC) coding apparatus for coding inputted information into a generator matrix having a dual diagonal matrix format includes: a parity bit generation unit configured to generate an arbitrary parity bit; a temporary parity bit generation unit configured to constitute the inputted information with circulants, and shift and combine the respective circulants at each row to generate a temporary parity bit; a corrected bit generation unit configured to generate corrected bits of parity bits by using an output of the temporary parity bit generation unit; and a parity bit correction unit configured to correct the temporary parity bit by reflecting an output of the corrected bit generation unit to the output of the temporary parity bit generation unit.
摘要:
Provided is an apparatus and method for decoding a Low Density Parity Check (LDPC) code based on prototype parity check matrixes. The apparatus, includes: a parity check matrix selecting means for determining multiple prototype parity check matrixes according to a sub-matrix size and a parallelization figure for processing the parity check matrix; a bit input means for receiving a log likelihood probability value for input bit according to the sub-matrix size and the parallelization figure; a check matrix process means for sequentially performing a partial parallel process on the parity check matrix based on the received log likelihood probability value and the determined multiple prototype parity check matrixes; and a bit process means for determining a bit level based on the partial-parallel processed parity check matrix value and recovering the input bit according to the sub-matrix size and the parallelization figure.
摘要:
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.
摘要:
Provided are a QR decomposition apparatus and method for a MIMO system. The QR decomposition apparatus includes: a norm calculator for calculating a vector size norm for a channel input; a Q column calculator for calculating a column value of a unitary matrix Q by multiplying a delayed channel input with √{square root over (norm)}; an R row calculator for receiving the delayed channel input, the output of the Q column calculator, and 1/√{square root over (norm)}, and calculating a row value of an upper triangular matrix R; a Q update calculator for receiving the delayed channel input, the output of the R row calculator, and a delayed output of the Q column calculator, and calculating a Q update matrix value; and a norm update calculator for receiving a delayed output of the norm calculator and an output of the R row calculator, and outputting a norm update matrix value.
摘要:
The apparatus includes a radio frequency (RF) unit configured to arrange a plurality of symbols received through an antenna at a frequency domain, an analog to digital (AD) converter configured to converts the plurality of symbols arranged at the frequency domain to digital symbols, a fast Fourier transform (FFT) unit configured to transform the digital symbols through a fast Fourier transform scheme, a compensator configured to compensate a gain mismatch between an I-channel and a Q-channel of the transformed digital symbols, a mapping unit configured to the compensated digital symbols to a constellation diagram, and a detector configured to correlate the mapped symbols, extract correlation results, and detect a high throughput (HT) signal using the extracted correlation results.
摘要:
An association supporting apparatus in a wireless communication system includes: a transmission/reception unit configured to scan associable access points (APs) among a plurality of APs existing in a plurality of station (STA) wireless networks, and receive state information from the scanned APs; a calculation unit configured to calculate transmit opportunity (TXOP) periods with respect to the APs by using the received state information of the APs; and a determination unit configured to determine a predetermined AP among the plurality of scanned APs, considering usable power levels of the APs and the number of associable STAs during the calculated TXOP periods.
摘要:
Provided is an apparatus and method for encoding a Low Density Parity Check (LDPC) code using a message passing algorithm. The apparatus, includes: a parity calculating unit for operating a check node value on an input bit and a predetermined parity bit according to the message passing algorithm and calculating a parity bit; a parity correcting unit for correcting the calculated parity bit according to a parity check result of the calculated parity bit; and an output transform unit for combining the input bit and the corrected parity bit.