Abstract:
A method for transmitting a reference signal in a multi-antenna system is provided. The method includes: selecting at least one orthogonal frequency division multiplexing (OFDM) symbol in a subframe containing a plurality of OFDM symbols; allocating a channel quality indication reference signal (CQI RS) capable of measuring a channel state for each of a plurality of antennas to the selected at least one OFDM symbol; and transmitting the CQI RS, wherein the CQI RS is allocated to an OFDM symbol which does not overlap with an OFDM symbol to which a common reference signal to be transmitted to all user equipments in a cell or a dedicated reference signal to be transmitted to a specific user equipment in the cell is allocated.
Abstract:
The present invention relates to a method for transmitting, by a base station, a downlink signal using a plurality of transmission antennas comprises the steps of: applying a precoding matrix indicated by the PMI, received from a terminal, in a codebook to a plurality of layers, and transmitting the precoded signal to the terminal through a plurality of transmission antennas. Among precoding matrices included in the codebook, a precoding matrix for even number transmission layers can be a 2×2 matrix containing four matrices (W1s), the matrix (W1) having rows of a number of transmission antennas and columns of half the number of transmission layers, the first and second columns of the first row in the 2×2 matrix being multiplied by 1, the first column of the second row being multiplied by coefficient “a” of a phase, and the first column of the second row being multiplied by “−a”.
Abstract:
A method for transmitting control information via a PUCCH in a wireless communication system and an apparatus for performing the method are provided, the method including joint-coding a plurality of pieces of control information to obtain a single code word; obtaining a first modulated symbol sequence from the single code word; obtaining a plurality of second modulated symbol sequences corresponding to each slot in the PUCCH from the first modulated symbol sequence; cyclically shifting the plurality of second modulated symbol sequences in a time domain to obtain a plurality of third modulated symbol sequences; performing a Discrete Fourier Transform (DFT) precoding process on the plurality of third modulated symbol sequences to obtain a plurality of complex symbol sequences in a frequency domain; and transmitting the plurality of complex symbol sequences via the PUCCH.
Abstract:
A base station does not transmit any reference signal (RS) for channel measurement in a subframe in which transmission of an RS collides with transmission of a synchronization signal or a broadcast signal or in a resource block including the synchronization signal or the broadcast signal in the subframe. A user equipment assumes that any RS for channel measurement is not transmitted in a subframe or in a resource block when transmission of an RS collides with transmission of a synchronization signal or a broadcast signal in the subframe or in the resource block.
Abstract:
The present invention relates to a wireless communication system. More particularly, the present invention relates to a method for transmitting acknowledgement/negative ACK (ACK/NACK) in a wireless communication system which supports carrier aggregation, and to an apparatus for the method. A method in which a terminal transmits ACK/NACK in a wireless communication system that supports carrier aggregation comprises the following steps: receiving a physical downlink control channel (PDCCH); receiving a physical downlink shared channel (PDSCH) indicated by the PDCCH; and transmitting ACK/NACK for the PDSCH via a physical uplink control channel (PUCCH). A PUCCH format for transmitting ACK/NACK is selected by taking the number of aggregated carriers into account.
Abstract:
A method and a user equipment (UE) for generating a reference signal sequence in a wireless communication system are discussed. The method according to an embodiment includes receiving a cell-specific sequence hopping parameter from a base station. The cell-specific sequence hopping parameter is used to enable a sequence hopping for a plurality of UEs in a cell if a cell-specific group hopping parameter is used to disable a group hopping for the plurality of UEs in the cell. The method includes receiving a UE-specific sequence group hopping (SGH) parameter, specified to the UE, from the base station. The UE-specific SGH parameter is used to disable the sequence hopping, enabled by the cell-specific sequence hopping parameter. The method includes generating the reference signal sequence based on a base sequence number within a base sequence group. The base sequence number within the base sequence group is determined by the UE-specific SGH parameter.
Abstract:
A user equipment in wireless communication system is provided. The user equipment includes an antenna unit including a plurality of antennas, a control unit for grouping the plurality of antennas into a predetermined number of antenna groups and controlling separately transmission power of each of the predetermined number of antenna groups, and a transmitting unit, connected to the control unit, for transmitting at least one of data and control information to a base station via at least one of the predetermined number of antenna groups.
Abstract:
A method and apparatus for providing information indicating radio resources for multi-cell interference measurement at a BS so that a UE can more accurately measure interference are disclosed.
Abstract:
A method for allocating uplink and downlink physical channels to improve throughput of a wireless access system is disclosed. A method for allocating channels to optimize a wireless access system which supports radio frequencies comprises configuring one or more physical channels in a transmitter; allocating first physical channels to a receiver considering features of the one or more physical channels; and transmitting one or more control channels to the receiver through a predetermined physical channel of the first physical channels, the control channels including configuration information of the first physical channels allocated to the receiver.
Abstract:
A method for correcting errors in a multiple antenna system based on a plurality of sub-carriers and a transmitting/receiving apparatus supporting the same are disclosed. The method includes determining a phase shift based precoding matrix phase shifted at a predetermined phase angle, initially transmitting each sub-carrier symbol to a receiver in a packet unit by using the phase shift based precoding matrix, reconstructing the phase shift based precoding matrix to reduce a spatial multiplexing rate if a negative reception acknowledgement (NACK) is received from the receiver, and retransmitting the initially transmitted sub-carrier symbol by using the reconstructed phase shift based precoding matrix or by changing the phase shift based precoding matrix using offset information fed back from the receiver or random offset information.