A method and apparatus for accessing a contention-based uplink random access channel (RACH) in a single carrier frequency division multiple access (SC-FDMA) system are disclosed. A wireless transmit/receive unit (WTRU) randomly selects a RACH subchannel and a signature among a plurality of available RACH subchannels and signatures. The WTRU transmits a preamble using the selected signature via the selected RACH subchannel at a predetermined or computed transmission power. A base station monitors the RACH to detect the preamble and sends an acquisition indicator (AI) to the WTRU when a signature is detected on the RACH. When receiving a positive acknowledgement, the WTRU sends a message part to the base station. If receiving a negative acknowledgement or no response, the WTRU retransmits the preamble.

This application provides a communication method and a device. The method includes: sending, by a terminal device to a network device, a random access preamble, receiving, by the terminal device, a random access response (RAR) from the network device, wherein the RAR indicates a first resource, and sending, by the terminal device, downlink channel quality indication information to the network device, wherein the downlink channel quality indication information is carried in a Message 3 on the first resource, and the downlink channel quality indication information is used to indicate downlink channel quality.

The present invention relates to methods and arrangements in a wireless communication system, and in particular to uplink outer loop power control. A Node B identifies if a UE from which the Node B receives data is in a predetermined set of power challenged situations. The Node B transmits to the RNC an indication to hold the SIR target of the UE if the UE has been identified to be in a power challenged situation. As a consequence, the uplink outer loop power control (OLPC) procedure in the RNC will not change the SIR target of the UE. This implies that the output power level of the UE remains unchanged as long as the UE remains in the power challenged situation. Thus, user and network performance are improved in the wireless communication system.

The present invention relates to methods and arrangements in a wireless communication system, and in particular to uplink outer loop power control. A Node B identifies if a UE from which the Node B receives data is in a predetermined set of power challenged situations. The Node B transmits to the RNC an indication to hold the SIR target of the UE if the UE has been identified to be in a power challenged situation. As a consequence, the uplink outer loop power control (OLPC) procedure in the RNC will not change the SIR target of the UE. This implies that the output power level of the UE remains unchanged as long as the UE remains in the power challenged situation. Thus, user and network performance are improved in the wireless communication system.

A method and a device for transmitting/receiving a signal in a wireless communication system, according to one embodiment of the present invention, receive random access channel (RACH) configurations, and transmit a random access preamble on a specific RACH occasion (RO) on the basis of the RACH configurations. The number of reference points in a cell is derived on the basis of the number of RACH configurations, and each of the reference points can have a first timing advance (TA) value for an RACH process.

Aspects of the present disclosure provide procedures for handling interruption due to carrier switching for sounding reference signal transmission and for a carrier switching capability indication. A method by a user equipment (UE) is provided, generally including interrupting communication on a first component carrier (CC) to switch between the first CC and a second CC to transmit an uplink reference signal on the second CC and adjusting one or more parameters of an uplink transmission on the first component carrier to account for the interrupting communication on the second CC. In aspects, another method is provided in which, a UE receives a query from a base station for switching capability information of the UE for one or more carrier aggregation (CA) configurations and, in response to the query, provides an indication to the BS of the switching capability information of the UE for the one or more CA configurations.

To solve a problem that unless all of a plurality of AICH signature states are correctly decoded, the contents of reception results cannot be recognized and the error rate of signature decoding will be high. In this embodiment, a base station uses, out of a signature combination, the signature of at least one predetermined position to indicate information containing a preamble reception result and uses the signature of a position other than the predetermined position to indicate a transmission profile information number of an uplink channel for notification to a user equipment. Thus, the error rate related to reception results can be reduced as compared with the case where a single signature combination is used to notify all pieces of information.

A user terminal that communicates using a plurality of CGs (Cell Groups) including a first CG and a second CG, includes a PHY layer processing section that controls transmission power of a PRACH (Physical Random Access Channel) in each CG; and a MAC layer processing section that controls retransmission of the PRACH. When total transmission power of PRACHs of the plurality of CGs that are transmitted in an overlapping manner exceeds allowable maximum transmission power, the PHY layer processing section controls so as to preferentially allocate transmission power to the PRACH of the first CG, and based on notification which is reported from the PHY layer processing section when total transmission power of PRACHs of the plurality of CGs that are transmitted in an overlapping manner exceeds allowable maximum transmission power, the MAC layer processing section controls power-ramping in retransmission of the PRACH of the second CG.

A user terminal that communicates using a plurality of CGs (Cell Groups) including a first CG and a second CG, includes a PHY layer processing section that controls transmission power of a PRACH (Physical Random Access Channel) in each CG; and a MAC layer processing section that controls retransmission of the PRACH. When total transmission power of PRACHs of the plurality of CGs that are transmitted in an overlapping manner exceeds allowable maximum transmission power, the PHY layer processing section controls so as to preferentially allocate transmission power to the PRACH of the first CG, and based on notification which is reported from the PHY layer processing section when total transmission power of PRACHs of the plurality of CGs that are transmitted in an overlapping manner exceeds allowable maximum transmission power, the MAC layer processing section controls power-ramping in retransmission of the PRACH of the second CG.

The present disclosure relates to a method for transmitting and receiving a device-to-device (D2D) signal in a wireless communication system supporting D2D communication, said method, performed by a terminal, comprising the steps of: transmitting a cellular signal on a first subframe of a first component carrier; transmitting a D2D signal on a second subframe of a second component carrier; and when overlapping occurs between the first subframe and the second subframe, dropping the transmission of the D2D signal or reducing transmit power of the D2D signal in a specific interval.