Methods, systems, and devices for wireless communications are described. The described techniques provide for a user equipment (UE) to adjust a random access message that is transmitted to a base station in an asynchronous uplink transmission. The UE may use a constrained mapping of time and frequency resources for the random access message or transmit all portions of the message in a continuous transmission. The UE may also adjust the timing of the portions of the message. The base station may use a portion of the message, such as a preamble, to perform channel estimation for another portion of the message, such as a payload, to improve decoding of the transmitted message. Additionally, the UE may configure a waveform of the message to improve the continuous transmission of the message, for example by reducing interference between portions of the message.

A master station capable of controlling a slave station, includes a transmission unit, a reception unit, and a device control unit. The transmission unit and the reception unit communicate via a network with another communication apparatus capable of controlling a slave station. The device control unit acquires slave station information indicating slave stations to be controlled by the other communication apparatus, obtains, as a controlled slave station of the master station, a slave station which does not overlap with a slave station indicated by the slave station information based on the acquired slave station information, and generates control information for controlling the controlled slave station of the master station. The transmission unit transmits the control information to the controlled slave station of the master station.

A data communication method implemented by a communication system including transmitting data by a base station using an OFDM (Orthogonal Frequency Division Multiplexing) method as a downlink access method, transmitting to the base station, by a mobile terminal, a response signal in accordance with a result of reception of the data transmitted from the base station, transmitting to the base station, by the mobile terminal, a scheduling request signal to make a request for allocation of radio resources before transmitting data to the base station, and transmitting the response signal to the base station, a scheduling request signal to the base station, and a control process of, when a transmission timing of the response signal transmission process coincides with that of the scheduling request signal transmission process, allowing a radio resource for transmission of the scheduling request signal to be shared with transmission of the response signal.

Disclosed are a method, an apparatus, and a system for transmitting a signal using multiple carriers. In detail, provided are a wireless communication apparatus including a communication module; and a processor, wherein the processor obtains a common back-off counter for a carrier set on which data is to be transmitted, wherein the carrier set includes at least one component carrier, performs back-off of each of the component carriers using the obtained common back-off counter, and simultaneously transmits data through at least one component carrier in which the back-off is completed and a wireless communication method using the same.

Certain aspects of the present disclosure provide techniques for supporting UL-based mobility without DL zone signals. A DL zone signal may refer to a zone synchronization signal or a zone measurement reference signal. As described herein, a UE may perform certain operations upon power-up or RLF recovery, perform operations in each DRx cycle, and/or perform inter-zone handovers without relying on DL zone signals. Thus, aspects create a more user-centric environment and reduce and/or avoid transmission DL zone signals.

Provided are a method for communicating in a wireless communication system and a device using the same. A wireless device receives a switching command instructing the switching between a clear channel assessment (CCA) operation and a non-CCA operation in an unlicensed band. According to the switching command, the wireless device performs the CCA operation or the non-CCA operation in the unlicensed band.

Embodiments of the present disclosure describe systems, devices, and methods for grantless uplink transmissions in cellular networks. Various embodiments may include a detailed physical layer design for grantless uplink transmissions. In particular, various embodiments may include, for grantless uplink transmissions, enhanced mechanisms; transmission schemes; repeated transmissions; demodulation reference signal (DM-RS); power control mechanisms; and interference control mechanisms. Other embodiments may be described or claimed.

A method and apparatus for uplink transmission in an unlicensed band are provided. The apparatus performs CCA from a start of the CCA in an unlicensed band to confirm whether a channel is idle or not. If the channel is idle or not, the apparatus transmits uplink data.

Techniques, apparatus and methods are disclosed that enable reduced signaling overhead in a fifth generation (5G) wireless system. The system includes support for asynchronous uplink transmission, resource pool configuration, acknowledgement response and retransmission. For example, in a Type-1 transmission scheme, a user equipment (UE) selects one resource within the resource pool and transmits data in the uplink on the selected resource. In a Type-2 transmission scheme, a UE selects one resource within a scheduling request (SR) region in the resource pool, transmits the SR for the resource which contains the resource allocation for data transmission, and transmits the uplink data on the resource which is indicated in the SR information. In a Type-3 transmission scheme, a UE selects a resource within the SR region, transmits the SR on the selected resource with information on the resource selected for subsequent data transmission and transmits on the indicated resource if it receives an acknowledgment, in response to its transmitted SR.

In a communications system which complies with LTE including a base station which transmits data by using an OFDM (Orthogonal Frequency Division Multiplexing) method as a downlink access method, and a mobile terminal, in a case in which an uplink scheduling request signal is transmitted by using an S-RACH when an Ack/Nack signal is being transmitted by using an Ack/Nack exclusive channel, the transmission of the Ack/Nack signal is stopped while the uplink scheduling request signal is transmitted.