Abstract:
Methods, systems, and apparatuses are described for wireless communications. In one method, an uplink grant may be received over a licensed spectrum. A clear channel assessment (CCA) may be performed in response to the uplink grant to determine availability of an unlicensed spectrum. The CCA may be performed prior to a transmission associated with the uplink grant. In another method, scheduling information may be received over a licensed spectrum. An uplink grant may be transmitted over the licensed spectrum. The uplink grant may be based at least in part on the scheduling information. The uplink grant may be configured to trigger a CCA to determine availability of an unlicensed spectrum prior to a transmission associated with the uplink grant.
Abstract:
Methods and apparatuses are described in which an unlicensed spectrum is used for Long Term Evolution (LTE) communications. A first method includes performing clear channel assessment (CCA) to determine availability of an unlicensed spectrum, transmitting a request-to-send (RTS) signal to a set of user equipments (UEs) using the unlicensed spectrum when a determination is made that the unlicensed spectrum is available, and receiving, in the unlicensed spectrum, a common clear-to-send (CTS) signal and an individual CTS signal from one or more of the UEs in response to the RTS signal. A second method includes transmitting an RTS signal in an unlicensed spectrum or a V-RTS signal in a licensed spectrum, addressed to a set of UEs, and transmitting a CTS-to-self signal in the unlicensed spectrum along with the transmission of the V-RTS signal.
Abstract:
A method, a computer program product, and an apparatus are provided. The methods and apparatus for wireless communication include receiving a transmission, the transmission including a plurality of resource element groups (REGs). Aspects of the methods and apparatus include selecting a set of REGs from the plurality of REGs, the set of REGs including at least one REG and determining a traffic to pilot ratio (TPR) for the set of REGs based on the transmission and reference signals in the transmission. Aspects of the methods and apparatus include determining whether the set of REGs includes at least one of control information or data based on the TPR and canceling at least one of control information or data from the set of REGs based on the TPR.
Abstract:
Aspects of the present disclosure relate to techniques that may be utilized in networks with relatively dense deployments of nodes, such as remote radio heads (RRHs) and UE relays.
Abstract:
Collision handling of channel state information (CSI) reports is described for enhanced inter-cell interference coordination (elCIC), coordinated multipoint transmission (CoMP), and/or carrier aggregation (CA). Various aspects include prioritization schemes to resolve collisions between different CSI reporting sets in relation to the same component carrier (CC) used with transmission. Multiple stages of prioritization may identify CSI for a report based on various criteria. Tie breaker criteria may be defined for priority among CSI reports that changes for different subframes. In other aspects, PUSCH is utilized to transmit CSI for prioritized reporting sets in a subframe. In yet other aspects, if parallel PUCCH is supported, colliding CSI may be handled on a per PUCCH basis. Other aspects may allow for prioritizing periodic CSI within each of multiple CCs, and then prioritizing over different CCs to handle an interaction of CSI reports for CA, elCIC and/or CoMP.
Abstract:
In macro/RRH setups, channel state information reference signals (CSI-RS) and demodulation reference signals (DM-RS) may be used to decouple control and data transmission. Data transmission (e.g. for LTE Rel 10 and beyond) may be based on CSI-RS and DM-RS, while control may be received from a different set of cells or TxPs via CRS. Certain aspects of the present disclosure introduce a reporting framework, in which configuration of data-serving cells/TxPs may be carried out based on CSI-RS. In certain aspects, a new concept of CSI-RS groups, i.e., a set of CSI-RS ports that a UE considers as one group for precoding matrix indicator (PMI)/channel quality indicator (CQI)/rank indicator (RI) reporting, may be defined.
Abstract:
Techniques for sending control information relating to multiple downlink carriers and data on a single uplink carrier are described. A user equipment (UE) may be scheduled to transmit on a designated uplink carrier. The UE can multiplex control information for multiple downlink carriers with data for transmission on the uplink carrier in a same sub frame. Multiplexing may be performed according to a type of the control information and/or an ordering, priority, or association of the downlink carriers. The UE can selectively encode the control information separately for each downlink carrier and/or jointly across downlink carriers. The control information may be mapped to a single layer or multiple layers of a data channel. The UE may send the multiplexed control information and data on the data channel in the subframe while maintaining a single-carrier waveform.
Abstract:
Techniques for acknowledging data transmissions in a multi-carrier wireless communication network are disclosed. In one aspect, a UE determines a number of acknowledgement/negative acknowledgement (ACK/NACK) bits for a data transmission on one more component carriers (CCs) based on information obtained from a grant. The grant may be a downlink grant or an uplink grant, and the information obtained may include a number of CCs scheduled for data transmission and/or identifiers of the scheduled CCs. The UE may determine the number of ACK/NACK bits for acknowledging the data transmission based on the number of scheduled CCs and the identifier of each scheduled CC.
Abstract:
Certain embodiments of the present disclosure propose two efficient designs for a control channel in a Coordinated Multi-Point (CoMP) system. The proposed designs enable a user equipment (UE) to transmit acknowledgement (ACK) and negative acknowledgement (NACK) signals to one or more access points (APs) upon receiving transmissions from them.
Abstract:
Methods, apparatuses, and articles of manufacture are disclosed for adjusting a power level in connection with transmitting parallel uplink channels. In one aspect, a user equipment determines a power-limited condition in which a total transmit power of a group of power-controlled channels exceeds a maximum level in a transmission subframe. The user equipment may determine, in an iterative fashion, power backoff values by which to establish a configured maximum power level. The parallel uplink channels in the group may be prioritized and different backoff values may be used with channels having different priorities. The user equipment may thereafter adjust a transmit power of the power-controlled channels based on the configured maximum power level.