Abstract: A method, an apparatus, and a computer program product for wireless communication are provided in which downlink transmission modes in a wireless network are semi-statically configured for a mobile terminal in multiple-input multiple-output (MIMO) operation. The apparatus provides multiple precoding matrix indicators (PMIs) for a plurality of ranks. The provision of multiple PMIs by the apparatus enables balanced performance among different ranks and avoids less than optimal performance observed when the apparatus provides only a single rank and PMI that are generally not optimal for all transmissions. Feedback configuration information received by an apparatus defines a plurality of channel state information feedback instances conditioned on an admissible rank value. Rank indicators (RIs) and PMIs corresponding to the feedback instances are determined and feedback is provided for the channel state information feedback instances.

Abstract: Methods and apparatus are provided for assigning interference measurement resources. A method includes receiving at least one identifier, which determines, at least in part, at least one interference measurement resource that partially overlaps with another at least one interference measurement resource. The at least one interference measurement resource comprises a number of resource elements out of a set of resource elements. The method also includes measuring interference based at least in part on the at least one interference measurement resource.

Abstract: Techniques for determining resources to use for peer-to-peer (P2P) communication are disclosed. In an aspect, a network entity may receive feedback information (e.g., resource usage information and/or channel state information) from P2P devices and may perform resource partitioning based on the feedback information to allocate some of the available resources for P2P communication. The allocated resources may observe little or no interference from devices engaged in wide area network (WAN) communication. In another aspect, P2P groups may perform resource negotiation via a WAN connection (e.g., with little or no involvement by the WAN) to assign the allocated resources to different P2P groups. In yet another aspect, a device may autonomously determine whether to communicate with another device directly or via a WAN, e.g., whether to initiate P2P communication with another device and whether to terminate P2P communication.

Abstract: Certain aspects of the present disclosure provide techniques for implicitly linking aperiodic channel state information (A-CSI) reports to CSI-reference signal (CSI-RS) resources. In an aspect, the UE may be instructed to report on specific CSI-RS resource(s) via explicit signaling in the UE grant. Other aspects disclose techniques for implicit CSI-RS resource selection by the UE that require fewer signaling resources. Instead of explicitly signaling CSI-RS resources to the UE, the UE may implicitly select CSI-RS resource for CSI feedback reporting based on information known to the UE, e.g. a subframe on which a reporting request is received. This may reduce the impact of the additional signaling in the UE grant.

Abstract: A method of wireless communications includes adapting to downlink/uplink resource allocations. In particular, the downlink/uplink communications may be adjusted according to time division duplexed (TDD) configurations of serving and neighbor cells.

Abstract: A method of wireless communication at a serving base station identifies a potential interference condition based on an uplink/downlink configuration mismatch. The method includes signaling, to a neighbor base station, to restrict transmissions based on the identified potential interference condition. The transmissions may be restricted by beamforming the transmissions into a different direction and/or blocking transmissions on a frequency. The signaling prompts the neighbor base station to restrict downlink transmissions that will potentially interfere with uplink control channel transmissions received at the serving base station, or to restrict uplink transmissions, intended for the neighbor base station, that will potentially interfere with downlink control channel transmissions from the serving base station.

Abstract: Enhanced sounding reference signal (SRS) transmissions for multiple input, multiple output (MIMO) operation are disclosed in which a user equipment (UE) detects an observed interference level for each receiver chain of the UE. In response to an imbalance, the UE precodes a SRS targeting downlink operation to indicate the imbalance. The UE then transmits the precoded SRS. In alternative aspects, the precoded SRS vector may be determined by an evolved nodeB (eNB). In such aspects, the eNB determines the precoded SRS vector targeting downlink operations for the served UEs, wherein the determined precoded SRS vector includes determining the precoded SRS vector on a per UE basis, enabling the precoded SRS vector for either one or both of frequency division duplex (FDD) systems and time division duplex (TDD) systems, or enabling the precoded SRS vector for aperiodic SRS only. The eNB then transmits the determined precoded SRS vector to the UE.

Abstract: Provided is a method of wireless communication which includes selecting a codebook from a plurality of codebooks in accordance with an antenna characteristic, and transmitting an indication of the selected codebook. Each of the plurality of codebooks is associated with one of a plurality of antenna characteristics. In some designs, channel state information is received from a user equipment. The channel state information may be used to determine downlink scheduling and/or precoding. In some designs, the channel state information may include feedback elements associated with different subband granularity. The feedback elements may also indicate a selection of a subset of precoder column vectors and/or a phase offset between two groups of transmit antennas.

Abstract: A method for mitigating interference in a wireless network includes an eNodeB and/or a UE identifying interference. The eNodeB may identify the interfering TDD configurations based on a downlink signal of a neighboring eNodeB received during an uplink timeslot for a UE associated with the eNodeB. Likewise, the UE may identify an interfering UE based on an uplink signal received during a downlink timeslot for an eNodeB associated with the UE. The eNodeB performs interference management based at least in part on the identified interference.

Abstract: Techniques for determining resources to use for peer-to-peer (P2P) communication are disclosed. In an aspect, a network entity may receive feedback information (e.g., resource usage information and/or channel state information) from P2P devices and may perform resource partitioning based on the feedback information to allocate some of the available resources for P2P communication. The allocated resources may observe little or no interference from devices engaged in wide area network (WAN) communication. In another aspect, P2P groups may perform resource negotiation via a WAN connection (e.g., with little or no involvement by the WAN) to assign the allocated resources to different P2P groups. In yet another aspect, a device may autonomously determine whether to communicate with another device directly or via a WAN, e.g., whether to initiate P2P communication with another device and whether to terminate P2P communication.

Abstract: Methods and apparatus are provided for assigning interference measurement resources. A method includes receiving at least one identifier, which determines, at least in part, at least one interference measurement resource that partially overlaps with another at least one interference measurement resource. The at least one interference measurement resource comprises a number of resource elements out of a set of resource elements. The method also includes measuring interference based at least in part on the at least one interference measurement resource.

Abstract: Enhanced sounding reference signal (SRS) transmissions for multiple input, multiple output (MIMO) operation are disclosed in which a user equipment (UE) detects an observed interference level for each receiver chain of the UE. In response to an imbalance, the UE precodes a SRS targeting downlink operation to indicate the imbalance. The UE then transmits the precoded SRS. In alternative aspects, the precoded SRS vector may be determined by an evolved nodeB (eNB). In such aspects, the eNB determines the precoded SRS vector targeting downlink operations for the served UEs, wherein the determined precoded SRS vector includes determining the precoded SRS vector on a per UE basis, enabling the precoded SRS vector for either one or both of frequency division duplex (FDD) systems and time division duplex (TDD) systems, or enabling the precoded SRS vector for aperiodic SRS only. The eNB then transmits the determined precoded SRS vector to the UE.

Abstract: A method of wireless communications includes adapting to downlink/uplink resource allocations. In particular, the downlink/uplink communications may be adjusted according to time division duplexed (TDD) configurations of serving and neighbor cells.

Abstract: Methods and apparatus for enforcing codebook properties (e.g., constant modulus and/or finite alphabet) in adaptive and dual-stage codebooks are described. One example method generally includes receiving multiple feedback aspects of a channel for wireless communications determining multiple codewords based on the multiple feedback aspects, determining a final precoding matrix based on the multiple codewords, enforcing at least one codebook property in at least one of the multiple codewords or the final precoding matrix, applying the final precoding matrix to a plurality of spatial streams to form precoded spatial streams, and transmitting the precoded spatial streams. For certain aspects, enforcing the at least one codebook property includes quantizing elements in each of the multiple codewords and/or the final precoding matrix to the nearest value in a finite alphabet or to increase a performance metric.

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: A method for wireless communication is provided which includes receiving first and second signals transmitted from first and second antennas, respectively, determining a time offset between the first and second antennas based on the first and second signals, and reporting information regarding the time offset, including information regarding the time offset as being above or below a predetermined threshold. Another method for wireless communication is provided which includes generating channel state information feedback based on an assumption that the time offset is being compensated at a transmitter side. Yet another method for wireless communication is provided which includes receiving information regarding a time offset between multiple transmit antennas, including information regarding the time offset as being above or below a predetermined threshold, and adapting downlink transmissions to account for the time offset.

Abstract: Aspects disclosed herein relate to channel and interference estimations in a multiple transmission point environment including an eNB and RRHs. In the disclosed aspects, one or more transmission points can signal to a UE to measure channel state conditions based on a first and a second resource pattern. The UE may receive the signaling and perform interference estimation based at least in part on the first resource pattern, and channel estimation based at least in part on the second resource pattern. The UE may generate a channel state report based on the interference and channel estimations, and transmit the channel state report to a transmission point. The eNB may employ the received channel state report in scheduling one or more resources for use by the UE, and may select or adjust network traffic on the first and the second resource pattern, to affect the resulting channel and interference estimation.

Abstract: Certain aspects of the present disclosure provide methods and apparatus for performing coordinated multipoint (CoMP) channel state information (CSI) feedback under multiple channel and interference assumptions. One method generally includes receiving signaling indicating at least one or more interference measurement resources (IMRs) from a network and a configuration with one or more non-zero power reference signal (NZP-RS) resources in which one or more base stations transmit a RS, performing separate interference measurements at least on a per-IMR basis in one or more subframes by forming a baseline interference estimate based on the IMR and forming separate interference estimates based on adding interference from selected NZP-RS resources to the baseline interference estimate, and transmitting one or more CSI feedback reports that correspond to the interference measurements.

Abstract: A method, an apparatus, and a computer program product for wireless communication are provided. In an aspect, the apparatus may receive a set of configurations for an EPDCCH that are tied to a set of configurations received for a PDSCH. The apparatus may then receive and process the EPDCCH based on at least one configuration from the set of configurations for the EPDCCH. In another aspect, the apparatus may determine at least a first and second resource set configured for a control channel and may determine a common set of aggregation levels for the first and second resource sets. The apparatus may further determine first rate-matching parameters for the first resource set and second rate-matching parameters for the second resource set, and may process the control channel using the common set of aggregation levels and the first and second rate-matching parameters.

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.