A method of operating multiple time alignment timers (TimeAlignmentTimer) is provided for facilitating communication between and evolved Node B (eNB) and a User Equipment (UE) in a Long Term Evolution (LTE) system supporting multiple carriers. The method includes starting a first TAT of a first group including the primary cell, starting a second TAT when Timing Advance (TA) information on a second group not including the primary cell is received; and determining transmission of at least one of a Hybrid Automatic Repeat Request Acknowledgement/Negative-acknowledgement (HARQ ACK/NACK), a physical uplink control channel, and a sounding reference signal according to a start and an expiration of at least one of the first and second TATs.

Certain aspects of the present disclosure generally relate to wireless communication. In some aspects, a wireless communication device may receive one or more downlink control information (DCI) transmissions including a plurality of transmit power control (TPC) commands. The plurality of TPC commands may relate to an uplink channel transmit power for a plurality of uplink beam-pairs. The wireless communication device may determine the uplink channel transmit power for the plurality of uplink beam-pairs based at least in part on the plurality of TPC commands. Numerous other aspects are provided.

A method and an apparatus are provided for HARQ-ACK feedback information transmission in a traffic adaptive TDD system. The method includes obtaining a resource indicator and power control information in a physical downlink control channel (PDCCH) scheduling a physical downlink shared channel (PDSCH); identifying at least one physical uplink control channel (PUCCH) resource indicated by the obtained resource indicator; controlling power based on the obtained power control information; and transmitting the HARQ-ACK information in the identified at least one PUCCH resource using the controlled power.

A method and an apparatus for efficiently reporting user equipment (UE) are provided. A method of transmitting Power Headroom Report (PHR) of UE in a mobile communication system, includes configuring an evolved PHR including an indicator with respect of a variation factor of maximum transmission power of the UE, and transmitting the evolved PHR to an eNB. An eNB may know maximum transmission power of an UE and a variation factor thereof to enable efficient scheduling.

A method and an apparatus are provided for HARQ-ACK feedback information transmission in a traffic adaptive TDD system. The method includes receiving, by a User Equipment (UE), a System Information Block (SIB); obtaining, by the UE, a TDD uplink and downlink configuration that is indicated by current system information and does not support traffic adaptive UE, from the SIB; identifying, by the UE, implicit resources of Physical Uplink Control Channel (PUCCH) based on the TDD uplink and downlink configuration; obtaining, by the UE, a HARQ-ACK timing that supports a traffic adaptive UE; and transmitting, by the UE, the HARQ-ACK feedback information on determined PUCCH resources using a determined PUCCH format, based on the obtained HARQ-ACK timing.

A method and an apparatus for efficiently reporting user equipment (UE) are provided. A method of transmitting Power Headroom Report (PHR) of UE in a mobile communication system, includes configuring an evolved PHR including an indicator with respect of a variation factor of maximum transmission power of the UE, and transmitting the evolved PHR to an eNB. An eNB may know maximum transmission power of an UE and a variation factor thereof to enable efficient scheduling.

A radio system (110) comprising a first (120) and a second (130) radio unit which comprise a transmitter (122, 132) and a receiver (121, 131). The first radio unit (120) communicates with a first external radio unit (101) and the second radio unit (140) with a second external radio unit (102). Both transmitters (122, 132) are arranged to vary their output power level in response to a request from the external radio unit with which they are arranged to communicate. Both of the transmitters also vary their output power level in response to a variation in the transmitter output power level of the other radio unit.

Methods, systems, and devices for wireless communication are described. An energy harvesting wireless device may accumulate energy during an energy harvesting state for use in subsequent operation. In some cases, the energy harvesting wireless device may detect a trigger, such as a change in an energy status of the energy harvesting wireless device or explicit control signaling from a network, for transmitting a power headroom report (PHR), channel state information (CSI), or both. The energy harvesting wireless device may transmit the message including one or more of the PHR or the CSI and indicating that energy information (e.g., an energy report, an energy request, or both) is multiplexed with the PHR, the CSI, or both. In some cases, the message may include control information such as a medium access control (MAC) control element (MAC-CE).

Disclosed in the present application is a method for transmitting a sounding reference signal (SRS) from a terminal to a base station in a wireless communication system. More specifically, the method comprises a step of establishing a first subframe set and a second subframe set through an upper layer; a step of receiving, from the base station, a triggering indicator of the sounding reference signal; and a step of transmitting the sounding reference signal from a specific subframe to the base station, according to the triggering indicator, wherein each of the first subframe set and the second subframe set is associated with a power control process for transmitting an uplink data channel, and wherein the transmission power of the sounding reference signal is determined according to the bit size and/or the field value of the triggering indicator.

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.