Abstract:
A device and method for handling HARQ feedback in a mobile communication system are disclosed. The HARQ feedback handling method includes: analyzing a control message from a base station to recognize presence of HARQ feedback relationships between downlink carriers and uplink carriers; determining an uplink carrier (a downlink carrier) to support HARQ feedback in response to downlink traffic (uplink traffic) sent through a downlink carrier (an uplink carrier); and sending (receiving) HARQ feedback through the determined uplink carrier (downlink carrier).
Abstract:
A method and an apparatus for performing random access and uplink transmission of a User Equipment (UE) supporting Carrier Aggregation (CA) are provided. The method includes determining whether a Scheduling Request (SR) is pending, determining, when the SR is pending, whether an uplink transmission resource is available in a current Transmission Time Interval (TTI), determining, when the uplink transmission resource is not available, whether a Physical Uplink Control Channel (PUCCH) resource is configured for transmission of the SR, and initiating, when the PUCCH resource is not configured, a random access process in a primary cell. The random access method and apparatus of the present invention is advantageous to reduce the waste of transmission resources.
Abstract:
To solve the above-mentioned problem, a method in which a terminal reports channel state information comprises the following steps: receiving, plurality from a base station, information on a plurality of patterns to be used in a channel state measurement; receiving, from the base station, selection information for selecting a pattern from among the plurality of patterns that is to be used in the channel state information to be reported to the base station; measuring a channel state using the information on the plurality of patterns; and selecting a portion of the measured channel state based on the selection information, and reporting the selected portion to the base station. The above-described solution enables the efficient reporting of channel state information including CQIICSI, thus improving communication efficiency.
Abstract:
The present invention involves defining the operation of a terminal for determining which time alignment timer is to be applied to a certain condition when specific time alignment timers operate for each carrier-wave group in the event a wireless communication system uses a carrier aggregation technique. According to the present invention, a terminal may perform communication without malfunctions using a time alignment timer suitable for a certain condition. In detail, a method for a terminal to operate a time alignment timer according to the present invention comprises the steps of: receiving, from a base station, a message including a timing advance command and an index on a timing advance group (TAG); and operating the time alignment timer for the TAG, wherein the index has a value of 00 when the TAG includes a first cell. In the meantime, a method for a terminal to operate a time alignment timer according to the present invention comprises the steps of: operating a first time alignment timer for a first timing advance group (TAG) including a first cell; operating a second time alignment timer upon receipt of a timing advance command for a second TAG that does not include the first cell; and, if the first time alignment timer has expired, deeming the second time alignment timer to also be expired. In addition, a method for a base station to control a time alignment timer according to the present invention comprises the steps of: determining whether or not an uplink timing of a terminal needs correction; and transmitting a message including a timing advance command and an index on a timing advance group (TAG), wherein the index has a value of 00 when the TAG includes a first cell.
Abstract:
A Power Headroom Report (PHR) method and apparatus in a communication system are provided. The method includes acquiring information for a path loss reference, wherein the information for the path loss reference indicates whether the UE applies as the path loss reference either a downlink of a primary cell or a downlink of a secondary cell (SCell), triggering a power headroom report (PHR) if a path loss is changed more than a threshold for at least one activated cell which is used as the path loss reference, and obtaining power headroom information for each activated cell, if extended PHR is used and an uplink resource is allocated for new transmission.
Abstract:
A method and apparatus for configuring Power Headroom Report (PHR) of a User Equipment (UE) efficiently in a mobile communication system supporting carrier aggregation are provided. The method includes generating a header including a LCID for identifying extended PHR and L indicating a length of the extended PHR, and inserting Power Headrooms (PHs) of multiple activated carriers into the extended PHR of one of the carriers.
Abstract:
A method and apparatus for transmitting a power headroom (PH) report by a terminal in a mobile communication system supporting carrier aggregation are provided. The method includes determining a first maximum transmission power for a first serving cell of multiple activated serving cells based on uplink transmission of at least one other serving cell if the first serving cell transmits a physical uplink shared channel (PUSCH), determining a second maximum transmission power for a first serving cell of the multiple activated serving cells without consideration of uplink transmission of at least one other serving cell if the first serving cell does not transmit a PUSCH, calculating a PH for the first serving cell based on the first maximum transmission power or the second maximum transmission power, and transmitting, to a base station, an extended PH report including respective calculated PHs of the multiple activated serving cells on one of the multiple activated serving cells.
Abstract:
A method and an apparatus for transmitting multimedia broadcast single-frequency network (MBSFN) subframe configuration information of neighboring cells in a wireless system is provided. The method comprises: transmitting, by a base station of a serving cell, MBSFN subframe configuration information of the serving cell to a UE which accepts services from the serving cell via a broadcast control channel (BCCH); transmitting information on a subset relationship of MBSFN subframe configurations of the neighboring cells relative to the MBSFN subframe configuration of the serving cell to the UE which accepts services from the serving cell via the broadcast control channel (BCCH); performing, by the UE, measurements on the neighboring cells according to the subframe configuration information of the serving cell and the information on the subset relationship of the MBSFN subframe configurations of the neighboring cells relative to the MBSFN subframe configuration of the serving cell.
Abstract:
A method for transmitting uplink data using a plurality of cells by a user equipment (UE) in a mobile communication system supporting carrier aggregation (CA) is provided. The method includes determining first maximum transmission powers for the plurality of cells, each first maximum transmission power indicating a maximum transmission power for a cell of the plurality of cells, and a second maximum transmission power indicating a maximum total transmission power for all of the plurality of cells, determining an uplink transmission power for each cell of the plurality of cells by selecting a minimum value for the each cell, the minimum value being selected from among a required transmission power for the each cell and the first maximum transmission power for the each cell, scaling the determined uplink transmission powers for the plurality of cells so that a sum of the scaled uplink transmission powers is less than or equal to the second maximum transmission power, and transmitting the uplink data using the plurality of cells based on the scaled uplink transmission powers for the plurality of cells.
Abstract:
A method and an apparatus for efficiently transmitting or reporting a Power Headroom Report (PHR) of a User Equipment (UE) are provided. The method of transmitting the PHR of the UE in a mobile communication system includes configuring an extended PHR including an indicator corresponding to a variation factor of a maximum transmission power of the UE, and transmitting the extended PHR from the UE to a Base Station (BS). The BS may be notified of a maximum transmission power of the UE and a variation factor corresponding to the maximum transmission power in order to enable efficient scheduling.