Seoul National University

Korea Railroad Research Institute

Kyeong Jun Ko

Jung Woo Lee

Jae Ho Lee

Chi Hyung Ahn

Sung Kyu Jung

Jung Tai Kim

Sung Soo Park

Jae Hee Kim

Seh Chan Oh

Moo Sun Kim

Jai Sung Hong

Sang Hoon Chang

An apparatus and method for protecting a communication device of a railroad car is provided. The apparatus includes an antenna portion configured to include main antennas and an auxiliary antenna, a main receiver configured to check a magnitude of a received signal transferred through the main antennas of the antenna portion, an auxiliary receiver configured to check a magnitude of a received signal transferred through the auxiliary antenna of the antenna portion, and a controller configured to compare the magnitude of the signal received by the main receiver and the magnitude of the signal received by the auxiliary receiver, determine whether there is a jamming signal according to a comparison result, and take a preset countermeasure when it is determined that there is a jamming signal.

Apparatus and method for protecting communication device of railroad car

Disclosed are a railway vehicle braking system and method. The railway vehicle braking system includes a braking command generating unit generating a braking command to stop a railway vehicle, a comparison unit determining whether the braking command has been changed, a delay unit delaying and outputting the braking command depending upon a determination result from the comparison unit, and a digital-to-analog converter converting the braking command, which has been delayed by the delay unit, into an analog signal and inputting the analog signal to an actuator.

Railway vehicle braking system and method

Disclosed is a multiple-input multiple-output (MIMO) system including a transmitting end and a receiving end, wherein the transmitting end includes: a hierarchical codebook in which at least one base codebook is designated as the upper matrix and a child codebook generated based on a chordal distance between respective codewords configuring the base codebook is designated as the lower matrix; a scheduler configured to receive channel state information from the receiving end and select precoding matrices from the hierarchical codebook based on the channel state information; and a precoder configured to apply the precoding matrices selected in the scheduler to data to be transmitted to the receiving end and transmit the selected precoding matrices through a plurality of antennas.

MIMO system and method of generating hierarchical codebook therefor

A method for generating a hybrid codebook for a Multi-User Multiple-input Multiple-Output (MU-MIMO) system includes the steps of: generating a parent matrix set including a plurality of M&#xd7;M unitary matrices when the number of transmitter antennas is M; and generating a child matrix set dependent on the parent matrix set by using training vectors included in a random training set and each column for each unitary matrix of the parent matrix set as an initial vector codebook.

Method for generating hybrid codebook and hybrid MU-MIMO system

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Seoul, South Korea

Kyeong Jun Ko