Lg Electronics Inc.

Yonsei University

Hyuk Jin Chae

Dong Ku Kim

Byoung Hoon Kim

Han Byul Seo

Sung Yoon Cho

Jang Hoon Yang

Ki Jun Kim

Suck Chel Yang

Hyung Tae Kim

Kaibin Huang

Yo Han Kim

Soon Suk Roh

Jin Young Jang

Bin Chul Ihm

Wook Bong Lee

Sung Ho Cho

Provided is a method and a device for precoding in a wireless communication system. The method for precoding comprises the following steps: generating a first precoding matrix, W, for deciding the transmission power of one transmission antenna from a plurality of transmission antennas as the maximum power per antenna; generating a zero forcing (ZF) precoding matrix, T, which does not influence the transmission antenna having the power which is decided as the maximum power per antenna, based on the (i&#x2212;1)precoding matrix W(i=2, 3, . . . ); determining &#x3b1;, a constant which has the transmission power of one transmission antenna from the rest of the transmission antennas, which do not have the transmission power as the maximum power per antenna, based on the T; and generating the iprecoding matrix Wbased on the Tand the &#x3b1;.

Method and device for precoding in wireless communication system

Provided is a method and a device for generating a precoding matrix in a wireless communication system. The method for generating the precoding matrix comprises a step of receiving from a terminal feedback including information on the error angle &#x3b8; of channel direction information (CDI), which indicates the direction of a channel direction vector, and a step of generating the precoding matrix based on the information on the error angle &#x3b8; of the CDI, wherein the error angle &#x3b8; of the CDI indicates the angle between the channel direction vector and a quantized channel direction vector, and includes at least one of a channel quantization error component, a channel feedback delay error component, and a channel estimation error component.

Method and device for generating precoding matrix in wireless communication system

The method for channel information feedback based on multiple cell collaboration comprises a step wherein first channel quality information including the channel information between the terminal and base station is transmitted to the base station; a step wherein after the first channel quality information is sent; a channel quality information request message is received from the base station; and a step wherein in response to the channel quality information request message, second channel quality information is sent, including channel information between the terminal and the base station and adjacent base stations.

Method and apparatus for data transmission based on multiple cell collaboration

A feedback method for interference alignment in wireless network having K transmitters and K receivers, the method including: transmitting, by a transmitter n&#x2212;1, a precoding vector of the transmitter n&#x2212;1 (n being an integer between 2 and K&#x2212;1) to a receiver n+1; calculating, by the receiver n+1, a precoding vector of a transmitter n using the precoding vector of the transmitter n&#x2212;1; and transmitting, by the receiver n+1, the precoding vector of the transmitter n to the transmitter n.

Feedback method for interference alignment in wireless network

A method for interference alignment in wireless network having 3 transmitters and 3 receivers which are equipped with M antennas is provided. The method comprising: transmitting, performed by each of the 3 transmitters, a pilot signal known to the 3 receivers; estimating, performed by each of the 3 receivers, each channel from transmitter; transmitting, performed by each of the 3 receivers, feedback information to target transmitter; and determining, performed by transmitter 2 and transmitter 3, a precoding vector; wherein a degree of freedom (DoF) of a transmitter 1 is (M/2&#x2212;&#x3b1;), a DoF of the transmitter 2 or the transmitter 3 is M/2.

Method for interference alignment in wireless network

A power control method for interference alignment in wireless network having K transmitters and K receivers is provided. The method includes: receiving, performed by receiver n (n is an integer, 1&#x2266;n&#x2266;K&#x2212;1), a power indication signal of transmitter n+1 from the transmitter n+1; determining, performed by the receiver n, power of transmitter n; and transmitting, performed by the receiver n, a power indication signal of transmitter n to the transmitter n, wherein the power of transmitter n is determined based on a residual interference of the receiver n, and the power indication signal of transmitter n indicates a minimum transmission power or a maximum transmission power of transmitter n.

Power control method for interference alignment in wireless network

Disclosed are a feedback-transmitting method and data-transmitting method, and a method for generating a codebook that can be used in a system such as LTE-A. When multiple base stations operate in a cooperative mode, using a codebook generated according to the present invention, an existing codebook for single cell transmission can be used to generate a codebook for cooperative transmission.

Method for transmitting feedback information and data using a precoding codebook for multicell cooperative communication in a wireless communication system

A method and apparatus of configuring a multi-cell precoding matrix for a multiple input multiple output (MIMO) operation in a wireless communication system in which a plurality of base stations participate in cooperative communication is provided. A multi-cell precoding matrix is configured using one or more single-cell precoding matrices, and wherein coefficients to be multiplied by the single-cell precoding matrices satisfy a condition in which the product between the multi-cell precoding matrix and a Hermitian matrix of the multi-cell precoding matrix is a unitary matrix. According to the embodiment of the present invention, it is not necessary for all base stations to perfectly know channel information. In addition, a feedback overhead is not high, and complexity is low.

Method and apparatus for cooperative MIMO transmission operation in multicell wireless network

A method for transmitting channel information in a multi-antenna system, the method includes calculating channel quality information (CQI) with respect to each mode, comparing the CQI with respect to each mode to a threshold value with respect to each mode, and transmitting CQI with respect to a mode having higher CQI than the threshold value as channel information. Good performance can be achieved regardless of the number of users or an SNR of users.

Growing community of inventors

Seoul, South Korea

Hyuk Jin Chae