Abstract:
A method for efficiently transmitting and receiving control information through a Physical Downlink Control Channel (PDCCH) is provided. When a User Equipment (UE) receives control information through a PDCCH, the received control information is set to be decoded in units of search spaces, each having a specific start position in the specific subframe. Here, a modulo operation according to a predetermined first constant value (D) is performed on an input value to calculate a first result value, and a modulo operation according to a predetermined first variable value (C) corresponding to the number of candidate start positions that can be used as the specific start position is performed on the calculated first result value to calculate a second result value and an index position corresponding to the second result value is used as the specific start position. Transmitting control information in this manner enables a plurality of UEs to efficiently receive PDCCHs without collisions.
Abstract:
A method of transmitting scheduling information in time-division-duplex (TDD) system is provided. The method comprises configuring a radio frame, the radio frame comprising at least one downlink subframe and at least one uplink subframe, wherein a downlink subframe is reserved for downlink transmission and an uplink subframe is reserved for uplink transmission, and transmitting scheduling information on a downlink control channel in a downlink subframe, the scheduling information comprising an uplink indicator and uplink resource assignment, the uplink indicator indicating which at least one uplink subframe the uplink resource assignment is valid for. Data can be efficiently transmitted by using an uplink indicator which indicates a specific location of a subframe.
Abstract:
The present invention relates to a method and apparatus for reducing inter-cell interference in a wireless communication system. The method for reducing inter-cell interference in a wireless communication system according to one embodiment of the present invention includes: a step in which a first terminal receives, from a first cell, scheduling information for the transmission of a first signal to a second cell; and a step in which the first terminal transmits the first signal to the second cell on the basis of the scheduling information. The scheduling information is provided by the first cell in the event an uplink or downlink transmission of the first cell is interfered with by an uplink or downlink transmission of the second cell. The first signal indicates a request for reducing the transmitting power of the second cell or of the second terminal served by the second cell.
Abstract:
A method for transmitting and receiving uplink signals using an optimized rank 3 codebook is disclosed. The optimized rank 3 codebook includes 6 precoding matrix groups, each of which has 1 variable having an amplitude of 1. Preferably, the optimized 4Tx rank 3 codebook has 12 precoding matrix, two precoding matrixes are selected from each the above 6 precoding matrix groups considering chordal distance and the number of precoding matrix.
Abstract:
A method of indicating destination stations, performed by an access point (AP), in a wireless local area network (WLAN) system supporting multi-user multiple input multiple output (MU-MIMO) is provided. The method includes transmitting a sounding request frame to the plurality of destination stations to transmit a sounding frame used for channel estimation between the AP and each destination station, receiving the sounding frame in response to the sounding frame request from each station, and transmitting a first data frame spatially multiplexed with respect to the plurality of destination stations by performing channel estimation on the basis of the sounding frame, wherein the sounding request frame comprises a group identifier (ID) indicating the plurality of destination stations.
Abstract:
A method for transmitting uplink signals, which include ACK/NACK signals, control signals other than the ACK/NACK signals, and data signals, is disclosed. The method comprises serially multiplexing the control signals and the data signals; sequentially mapping the multiplexed signals within a specific resource region in accordance with a time-first mapping method, the specific resource region including a plurality of symbols and a plurality of virtual subcarriers; and arranging the ACK/NACK signals at both symbols near symbols to which a reference signal of the plurality of symbols is transmitted. Thus, the uplink signals can be transmitted to improve receiving reliability of signals having high priority.
Abstract:
A method for transmitting information of resources for use in transmission of ACK/NACK signals in a mobile communication system is disclosed. An example method for receiving ACK/NACK signals in a mobile communication system is also disclosed. When resources for transmission of data and resources for transmission of control information of the data are scheduled through virtual unit resources, the method identifies information of resources for receiving an ACK/NACK signal for transmission data mapped to information of at least one of a virtual unit resource allocated to the transmission data and a virtual unit resource allocated to control information of the transmission data, and receives the ACK/NACK signal for the transmission data through the information of resources for receiving the ACK/NACK signal.
Abstract:
A method of transmitting PMI (precoding matrix indicator) information in an uplink MIMO system is disclosed. The present invention includes the steps of receiving channel information from a user equipment and transmitting information on a resource allocated to the user equipment in uplink transmission and PMI information indicating a precoding matrix to apply to a region of the resource among a plurality of precoding matrices to the user equipment based on the received channel information, wherein the resource allocated to the user equipment is allocated by a bundle unit of a prescribed number of subcarriers, wherein each of a plurality of the precoding matrices are applied to regions generated from dividing a whole frequency band into a prescribed number of regions, respectively, and wherein the precoding matrix applied to the resource among a plurality of the precoding matrices has a maximum area resulting from overlapping a frequency band occupied by the allocated resource with a frequency band having the precoding matrix applied thereto.
Abstract:
A method for transmitting data by applying a precoding matrix in an open-loop multiple input multiple output (MIMO) system is disclosed. The method comprises selecting a precoding matrix and applying the selected precoding matrix to data during initial transmission; selecting a precoding matrix and applying the selected precoding matrix to data to be retransmitted; and retransmitting the data to which the precoding matrix is applied, wherein an index of the precoding matrix applied to the data is determined based on the times of current retransmission times of the data and index of the precoding matrix applied during initial transmission of the data.
Abstract:
A method for transforming data to reduce an amount of data in a communication system equipped with several sub-carriers, and a data transmission method using the same are disclosed. The method for transmitting data using a Discrete Cosine Transform (DCT) in a communication system based on a plurality of sub-carriers includes: a) performing a Discrete Cosine Transform (DCT) on first data; b) selecting a predetermined number of data from among the DCT-processed first data, and performing data processing on the selected data; and c) transmitting the data-processed resultant data to a reception end. A method for reducing an amount of overhead of transmission data for use in the multi-antenna communication system is disclosed.