Abstract: Provided is a constellation rotation relay system and constellation rotation relay method which can acquire full diversity gain by performing constellation rotation for a channel matrix in a relay network when configuring a virtual MIMO channel. The constellation rotation system includes a matrix creator for creating a symbol matrix by configuring a symbol transmitted in parallel from a source of a relay network; and a constellation rotation unit constellation rotating the symbol in the symbol matrix by adding a constellation rotation matrix to the created symbol matrix.

Abstract: Provided is a constellation rotation relay system and constellation rotation relay method which can acquire full diversity gain by performing constellation rotation for a channel matrix in a relay network when configuring a virtual MIMO channel. The constellation rotation system includes a matrix creator for creating a symbol matrix by configuring a symbol transmitted in parallel from a source of a relay network; and a constellation rotation unit constellation rotating the symbol in the symbol matrix by adding a constellation rotation matrix to the created symbol matrix.

Abstract: Provided is a constellation rotation relay system and constellation rotation relay method which can acquire full diversity gain by performing constellation rotation for a channel matrix in a relay network when configuring a virtual MIMO channel. The constellation rotation system includes a matrix creator for creating a symbol matrix by configuring a symbol transmitted in parallel from a source of a relay network; and a constellation rotation unit constellation rotating the symbol in the symbol matrix by adding a constellation rotation matrix to the created symbol matrix.

Abstract: Provided is a fine frequency synchronization method of a WiBro system, and particularly, a fine frequency synchronization method which measures a spread degree of a received signal of an adjacent subcarrier using orthogonality of PN sequences and thereby estimates a frequency offset, in a base station or a wireless repeater without using a GPS receiver. The fine frequency synchronization method includes: (a) performing despreading on received adjacent subcarrier sequences, using a PN sequence transmitted from a transmitting party; (b) obtaining ratios of correlative values obtained by the despreading; and (c) estimating a frequency offset on the basis of the ratio of correlative values. Accordingly, fine frequency offset estimation with relatively low complexity is possible without using a GPS receiver in a WiBro environment where interference signals of other base stations or repeaters exist.

Abstract: Provided is a fine frequency synchronization method of a WiBro system, and particularly, a fine frequency synchronization method which measures a spread degree of a received signal of an adjacent subcarrier using orthogonality of PN sequences and thereby estimates a frequency offset, in a base station or a wireless repeater without using a GPS receiver. The fine frequency synchronization method includes: (a) performing despreading on received adjacent subcarrier sequences, using a PN sequence transmitted from a transmitting party; (b) obtaining ratios of correlative values obtained by the despreading; and (c) estimating a frequency offset on the basis of the ratio of correlative values. Accordingly, fine frequency offset estimation with relatively low complexity is possible without using a GPS receiver in a WiBro environment where interference signals of other base stations or repeaters exist.

Abstract: Provided is a constellation rotation relay system and constellation rotation relay method which can acquire full diversity gain by performing constellation rotation for a channel matrix in a relay network when configuring a virtual MIMO channel. The constellation rotation system includes a matrix creator for creating a symbol matrix by configuring a symbol transmitted in parallel from a source of a relay network; and a constellation rotation unit constellation rotating the symbol in the symbol matrix by adding a constellation rotation matrix to the created symbol matrix.

Abstract: The present invention relates to a mass flow controller for a control purge and a managing method of the same. When a user sets the mode to a control purge mode capable of controlling a maximum flowing amount for constantly maintaining a maximum flowing amount when performing a purge function after the user sets a purge function mode based on a purpose of use of a mass flow controller, a control circuit compares a set value of a flowing amount inputted based on a user's selection with a previously set threshold value and controls a valve for constantly maintaining a maximum flowing amount by switching to a gain resistor for a purge mode having a gain value capable of performing a purge function and controls a valve for thereby accurately controlling a small flowing amount by switching to a gain resistor for a common control mode having a gain value capable of performing a common control function.

Abstract: The present invention relates to a mass flow controller for a control purge and a managing method of the same. When a user sets the mode to a control purge mode capable of controlling a maximum flowing amount for constantly maintaining a maximum flowing amount when performing a purge function after the user sets a purge function mode based on a purpose of use of a mass flow controller, a control circuit compares a set value of a flowing amount inputted based on a user's selection with a previously set threshold value and controls a valve for constantly maintaining a maximum flowing amount by switching to a gain resistor for a purge mode having a gain value capable of performing a purge function and controls a valve for thereby accurately controlling a small flowing amount by switching to a gain resistor for a common control mode having a gain value capable of performing a common control function.