Abstract:
A method, a user equipment, and a base station for maintaining uplink synchronization in a wireless communication system supporting carrier aggregation are discussed. The method of maintaining uplink synchronization at a user equipment according to an embodiment includes receiving a physical downlink control channel (PDCCH) order. The PDCCH order indicates an initiation of a random access procedure and includes a carrier indicator field and a predefined set of values of a 1-bit flag indicating a localized/distributed resource block assignment, and a resource block assignment field. The method further includes transmitting a random access preamble through an uplink component carrier corresponding to a value of the carrier indicator field among a plurality of uplink component carriers.
Abstract:
A method for uplink transmission in a wireless communication system, and a user equipment (UE) therefore are discussed. The method according to an embodiment includes determining a transmission power of a first uplink signal; determining a transmission power of a second uplink signal; preparing to transmit the first uplink signal toward a first cell belonging to a first timing advance group (TAG); preparing to transmit the second uplink signal toward a second cell belonging to a second TAG; and if the first uplink signal toward the first cell belonging to the first TAG at an nth subframe and the second uplink signal of the second cell belonging to the second TAG at an (n+1)th subframe are overlapped, determining whether to adjust a total transmission power or drop the first uplink signal at the nth subframe.
Abstract:
A method for transmitting a reference signal for channel measurement (CSI-RS) to a user equipment; a base station therefore; a method for receiving a CSI-RS; and the user equipment therefore are discussed. The method for transmitting a CSI-RS according to one embodiment includes transmitting CSI-RS pattern information for indicating a pattern of time-frequency resource to be nulled, hereinafter referred to as null CSI-RS pattern, and CSI-RS subframe information for indicating in which subframe the null CSI-RS pattern occurs; and nulling a time-frequency resource corresponding to the null CSI-RS pattern in a subframe corresponding to the CSI-RS subframe information, hereinafter referred to as null CSI-RS subframe, based on the CSI-RS pattern information and the CSI-RS subframe information. The CSI-RS subframe information includes information indicating a periodic interval with which the null CSI-RS subframe occurs. The periodic interval corresponds to a plurality of subframes.
Abstract:
A method and terminal are described for allocating resources for transmitting a signal in a multiple-input multiple-output (MIMO) wireless communication system. An uplink signal is transmitted using L layers at a terminal in a multiple-input multiple-output (MIMO) wireless communication system. Modulation symbols are generated by modulating output bit sequences of an interleaver matrix by a unit of log2Q bits, where Q is a modulation order. Each of the output bit sequences has a size of L·log2Q bits. The modulation symbols are mapped to the L layers and transmitted by using the L layers. The output bit sequences are generated by reading out entries of the interleaver matrix, column by column.
Abstract:
A method of controlling an uplink transmission in a wireless communications system, and a user equipment therefore are discussed. The method according to one embodiment includes configuring the user equipment with multiple component carriers; receiving first configuration information for allocating one or more component carrier sets; receiving second configuration information for periodically transmitting an uplink signal; receiving control information for configuring states of component carriers, by which a downlink component carrier and an uplink component carrier are controlled to be in a same state; and performing a procedure for periodically transmitting the uplink signal on an uplink component carrier in use of the first configuration information, the second configuration information and the control information. When the uplink component carrier is in the active state, a transmission of the uplink signal is performed. When the uplink component carrier is in the non-active state, the transmission of the uplink signal is skipped.
Abstract:
A method and communication apparatus for controlling transmission powers in a wireless communication system supporting a plurality of component carriers are described. When a sounding reference symbol (SRS) transmission overlaps with a physical uplink shared channel (PUSCH) transmission and a physical uplink control channel (PUCCH) transmission in a time domain, a check is made as to whether a total of a PUSCH transmission power for the PUSCH transmission on a first component carrier, a PUCCH transmission power for the PUCCH transmission on the first component carrier and a SRS transmission power for the SRS transmission on a second component carrier exceeds a maximum transmission power configured for the communication apparatus. The SRS is dropped if the total of the PUSCH transmission power, the PUCCH transmission power and the SRS transmission power exceeds the maximum transmission power configured for the communication apparatus.
Abstract:
A method for reporting power headroom value in a wireless access system that supports a carrier aggregation, and a user equipment (UE) for performing the method are discussed. The method according to one embodiment includes receiving a uplink transmission grant allocating uplink resources on a predetermined subframe in an anchor uplink component carrier (UL CC); obtaining power headroom value for the anchor UL CC, if the UE is configured with a simultaneous physical uplink control channel (PUCCH) and physical uplink shared channel (PUSCH) transmission; and reporting the power headroom value to a base station. The power headroom value is calculated.
Abstract:
A method of transmitting a reference signal in a wireless communication system, and an apparatus therefore. The method according to one embodiment includes selecting one or more values among a set {0, 3, 6, 8, 10}; cyclically shifting a base sequence based on the one or more values selected from the set {0, 3, 6, 8, 10}; and transmitting the reference signal based on the cyclically shifted base sequence to a base station. The reference signal is transmitted on a first orthogonal frequency division multiplexing (OFDM) symbol and a second OFDM symbol. The first OFDM symbol is a second OFDM symbol among 7 OFDM symbols in one slot. The second OFDM symbol is a sixth OFDM symbol among the 7 OFDM symbols in the slot.
Abstract:
A method and apparatus for transmitting control information are discussed. The method can include generating uplink control information (UCI) and transmitting the UCI through an physical uplink control channel (PUCCH) in a subframe, wherein when the subframe is configured for transmission of a scheduling request (SR) and when transmission of a hybrid automatic repeat request (HARQ)-acknowledgement (ACK) coincides with the subframe, transmission power of the PUCCH is determined based on a number of HARQ-ACK information bits and a SR bit. A value of the SR bit can be determined by whether or not the subframe is configured for a scheduling request.
Abstract:
A method is described for transmitting a control signal in a wireless communication system. A wireless communication system supporting multiple antennas, transmits, by a user equipment (UE), a control signal on an uplink control channel at a subframe i. Furthermore, an uplink transmit power PPUCCH(i) for the uplink control channel at the subframe i is determined based on a mathematical equation. Additionally, the mathematical equation includes a min function and uses parameters including PCMAX(i), P0—PUCCH, ΔF—PUCCH(F), g(i), PL, Δ(M) and PL where PCMAX(i) is a configured UE transmit power in subframe i, P0—PUCCH is a parameter composed based on provisions by a higher layer, ΔF—PUCCH(F) is a parameter provided by the higher layer, PL is a downlink pathloss estimate calculated in the UE, and g(i) is a value relating to a UE specific value.