Patent Description:
The following relates generally to wireless communication, and more specifically to enhanced coordinated multipoint (CoMP) operation.

Examples of such multiple-access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, and orthogonal frequency division multiple access (OFDMA) systems. A wireless multiple-access communications system may include a number of base stations, each simultaneously supporting communication for multiple communication devices, which may each be referred to as a user equipment (UE).

In some cases, a UE may communicate with more than one base station using CoMP operations. However, in some systems joint transmission CoMP operations may be based on coherent transmissions from each base station. This may not be available for base stations that have a less than ideal backhaul, which can limit the usefulness of joint transmissions and reduce overall system throughput.

<NPL>, discloses three different options for designing new port/scrambling ID indicators within <NUM> bits of antenna port/ scrambling ID indicator in the current DCI format. One option is to remove the nSCID indication and add additional port information, where the <NUM> bits value indicates different numbers of layers and port numbers according to the number of codewords. Another solution is to carry a <NUM> bit signal carrying port replacement indication using RRC high layer signalling.

<CIT> discloses a system in which data can be transmitted by one of two base stations, each base station using a different set of parameters containing a number of CRS ports, ZP CSI-RS configuration, PDSCH starting symbol for each cell. The different parameters sets are configured using RRC. PQI bits in DCI format 2D are used to indicate one of the configuration parameters set used for data reception by the UE.

<NPL>, discusses signalling systems for quasi co location information. RRC is used to signal multiple parameter sets to the UE. Each parameter set contains values for the CRS pattern, the MBSFN configuration, the NZP CSI-RS pattern and the ZP CSI-RS pattern. Then the base station uses a bit in DCI (either a new bit in format 2C or the nSCID bits) to indicate which PDSCH RE mapping and quasi-co-location parameter set to use.

<CIT>, describes a method for cancelling interference in a coordinated over multi point, CoMP, system, applied to a downlink cooperative transmission scheme using multiple transmission points, TPs. Quasi collocation and rate matching including start symbol and ending symbol are configured for a transport block and therefore for multiple consecutive codewords.

Independent claim <NUM> defines a method according to the invention. Independent claim <NUM> defines the corresponding apparatus according to the invention. Independent claim <NUM> defines the corresponding computer program according to the invention.

A user equpment (UE) may use multiple-input multiple-output (MIMO) layer specific and codeword specific communication configurations to communicate with multiple base stations. For example, multiple base stations may be configured to provide coordinated multipoint (CoMP) transmissions to the UE. One or more of the base stations may transmit a set of communications configurations to the UE that includes at least one MIMO layer specific or codeword specific configuration. The UE may then receive a dynamic indication of which communication configuration to use during a specific time period. The UE may then communicate with one or more of the base stations using the indicated configuration during the specified time period.

A method of wireless communication is described. The method may include receiving a set of communication configurations associated with a plurality of base stations, wherein at least one of the set of communication configurations comprises a MIMO layer specific configuration or a codeword specific configuration, receiving an indication of a communication configuration from the set of communication configurations and communicating with at least one base station of the plurality of base stations using the communication configuration.

An apparatus for wireless communication is described. The apparatus may include means for receiving a set of communication configurations associated with a plurality of base stations, wherein at least one of the set of communication configurations comprises a MIMO layer specific configuration or a codeword specific configuration, means for receiving an indication of a communication configuration from the set of communication configurations and means for communicating with at least one base station of the plurality of base stations using the communication configuration.

Another apparatus is described. The apparatus may include a processor, memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be operable to cause the processor to receive a set of communication configurations associated with a plurality of base stations, wherein at least one of the set of communication configurations comprises a MIMO layer specific configuration or a codeword specific configuration, receive an indication of a communication configuration from the set of communication configurations and communicate with at least one base station of the plurality of base stations using the communication configuration.

A non-transitory computer readable medium for wireless communication is described. The non-transitory computer-readable medium may include instructions to cause a processor to receive a set of communication configurations associated with a set of base stations, where at least one of the set of communication configurations comprises a MIMO layer specific configuration or a codeword specific configuration, receive an indication of a communication configuration from the set of communication configurations and communicate with at least one base station of the set of base stations using the communication configuration.

In some examples of the method, apparatus, or non-transitory computer-readable medium described above, the communication configuration comprises a channel state information (CSI) power offset configuration, a CSI subframe set configuration, a codebook restriction, a rate matching configuration, a quasi-colocation (QCL) indication, or any combination thereof.

In some examples of the method, apparatus, or non-transitory computer-readable medium described above, the rate matching configuration comprises a starting symbol for physical downlink shared channel (PDSCH) transmissions, an ending symbol for PDSCH transmissions, a multimedia broadcast multicast (MBMS) single frequency network (MBSFN) indication, a cell-specific reference signal (CRS) configuration, one or more non-zero power CSI reference signal (NZP CSI-RS) configurations, or any combination thereof.

Some examples of the method, apparatus, or non-transitory computer-readable medium described above may further include processes, features, means, or instructions for identifying a resource allocation for each of the set of base stations based on the communication configuration, where the communicating is based on the resource allocation.

Some examples of the method, apparatus, or non-transitory computer-readable medium described above may further include processes, features, means, or instructions for identifying a CSI-RS port configuration for the at least one base station based on the communication configuration. Some examples of the method, apparatus, or non-transitory computer-readable medium described above may further include processes, features, means, or instructions for transmitting a CSI report to the at least one base station, where the CSI report is based on the CSI-RS port configuration and the set of base stations.

In some examples of the method, apparatus, or non-transitory computer-readable medium described above, the CSI-RS port configuration is based on a number of receive ports for a UE and a number of transmit ports for the at least one base station. Some examples of the method, apparatus, or non-transitory computer-readable medium described above may further include processes, features, means, or instructions for generating an individual CSI report for the at least one base station based on the communication configuration, where the communication configuration is based on communication with a single base station. Some examples of the method, apparatus, or non-transitory computer-readable medium described above may further include processes, features, means, or instructions for transmitting the individual CSI report.

Some examples of the method, apparatus, or non-transitory computer-readable medium described above may further include processes, features, means, or instructions for generating a combined CSI report for each of the set of base stations based on the communication configuration, where the communication configuration is based on communication with the set of base stations. Some examples of the method, apparatus, or non-transitory computer-readable medium described above may further include processes, features, means, or instructions for transmitting the combined CSI report for each of the set of base stations.

Some examples of the method, apparatus, or non-transitory computer-readable medium described above may further include processes, features, means, or instructions for identifying a special subframe configuration for each of the set base stations based on the communication configuration, where the communicating is based on the special subframe configuration.

In some examples of the method, apparatus, or non-transitory computer-readable medium described above, the special subframe configuration comprises a demodulation reference signal (DMRS) pattern, and where the communicating is based on the DMRS pattern. In some examples of the method, apparatus, or non-transitory computer-readable medium described above, the communication configuration comprises an uplink (UL) configuration and a downlink (DL) configuration.

In some examples of the method, apparatus, or non-transitory computer-readable medium described above, the communication configuration comprises an enhanced physical downlink control channel (ePDCCH) configuration, and where the communicating is based on the ePDCCH configuration. In some examples of the method, apparatus, or non-transitory computer-readable medium described above, the ePDCCH configuration comprises one or more ePDCCH resource sets associated with the MIMO layer specific configuration or the codeword specific configuration.

In some examples of the method, apparatus, or non-transitory computer-readable medium described above, the set of base stations are coordinated according to a CoMP configuration that comprises a coordinated beamforming (CBF) mode, a dynamic point selection (DPS) mode, or a joint transmission (JT) mode, and where communicating is based on the CoMP configuration.

A method of wireless communication is described. The method may include transmitting a set of communication configurations associated with a plurality of base stations, wherein at least one of the set of communication configurations is based on a MIMO layer specific communication or a codeword specific communication, transmitting an indication of a communication configuration from the set of communication configurations and communicating with a UE using the communication configuration.

An apparatus for wireless communication is described. The apparatus may include means for transmitting a set of communication configurations associated with a plurality of base stations, wherein at least one of the set of communication configurations is based on a MIMO layer specific communication or a codeword specific communication, means for transmitting an indication of a communication configuration from the set of communication configurations and means for communicating with a UE using the communication configuration.

Another apparatus is described. The apparatus may include a processor, memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be operable to cause the processor to transmit a set of communication configurations associated with a plurality of base stations, wherein at least one of the set of communication configurations is based on a MIMO layer specific communication or a codeword specific communication, transmit an indication of a communication configuration from the set of communication configurations and communicate with a UE using the communication configuration.

A non-transitory computer readable medium for wireless communication is described. The non-transitory computer-readable medium may include instructions to cause a processor to transmit a set of communication configurations associated with a set of base stations, where at least one of the set of communication configurations is based on a MIMO layer specific communication or a codeword specific communication, transmit an indication of a communication configuration from the set of communication configurations and communicate with a UE using the communication configuration.

In some examples of the method, apparatus, or non-transitory computer-readable medium described above, the communication configuration comprises a CSI power offset configuration, a CSI subframe set configuration, a codebook restriction, a rate matching configuration, a QCL indication, or any combination thereof.

In some examples of the method, apparatus, or non-transitory computer-readable medium described above, the rate matching configuration comprises a starting symbol for PDSCH transmissions, an ending symbol for PDSCH transmissions, an MBSFN indication, a CRS configuration, one or more NZP CSI-RS configurations, or any combination thereof.

Some examples of the method, apparatus, or non-transitory computer-readable medium described above may further include processes, features, means, or instructions for identifying a resource allocation for each of the set of base stations based on the communication configuration, where the communicating is based on the resource allocation. Some examples of the method, apparatus, or non-transitory computer-readable medium described above may further include processes, features, means, or instructions for identifying a CSI-RS port configuration based on the communication configuration. Some examples of the method, apparatus, or non-transitory computer-readable medium described above may further include processes, features, means, or instructions for receiving a CSI report based on the CSI-RS port configuration and set of base stations.

In some examples of the method, apparatus, or non-transitory computer-readable medium described above, the CSI-RS port configuration is based on a number of receive ports for a UE and a number of transmit ports. Some examples of the method, apparatus, or non-transitory computer-readable medium described above may further include processes, features, means, or instructions for receiving an individual CSI report based on the communication configuration, where the communication configuration is based on communication between a UE and a single base station.

Some examples of the method, apparatus, or non-transitory computer-readable medium described above may further include processes, features, means, or instructions for receiving a combined CSI report based on the communication configuration, where the communication configuration is based on communication with the set of base stations. Some examples of the method, apparatus, or non-transitory computer-readable medium described above may further include processes, features, means, or instructions for identifying a special subframe configuration based on the communication configuration, where the communicating is based on the special subframe configuration.

In some examples of the method, apparatus, or non-transitory computer-readable medium described above, the special subframe configuration comprises a DMRS pattern, and where the communicating is based on the DMRS configuration. In some examples of the method, apparatus, or non-transitory computer-readable medium described above, the communication configuration comprises an UL configuration and a DL configuration.

In some examples of the method, apparatus, or non-transitory computer-readable medium described above, the communication configuration comprises ePDCCH configuration, and where the communicating is based on the ePDCCH configuration. In some examples of the method, apparatus, or non-transitory computer-readable medium described above, the set of base stations are coordinated according to a CoMP configuration that comprises a CBF mode, a DPS mode, or a JT mode, and where communicating is based on the CoMP configuration.

Some wireless communications systems may use coordinated multi-point (CoMP) transmissions in which two or more base stations may transmit data to a user equipment (UE). Such CoMP transmissions may use several CoMP schemes, including dynamic point selection (DPS) in which different base stations transmit data to a UE at different times, joint transmission (JT) in which two or more base stations contemporaneously transmit data to a UE, and coordinated beamforming (CBF) in which two or more base stations coordinate signal transmissions that reduce interference between the two or more base stations and/or with nodes in adjacent cells.

When communicating using CoMP transmissions, base stations and UEs may use multiple-input multiple-output (MIMO) techniques, where multiple transmit and receive antennas are used for sending and receiving signals, respectively. For example, the UE may communicate with different base stations using different sets of MIMO communication layers. In some cases, each base station communicates with the UE using a different layer i.e., a layer specific communication configuration, and in other cases each base station may utilize multiple layers to transmit a codeword (or transport block), i.e., a codeword specific (or transport block specific) communication configuration.

Thus, a layer specific configuration may include transmitting different layers to a UE from different base stations or transmission points (TPs), where the number of base stations corresponds to the number of layers transmitted (e.g., eight base stations for eight layers, where each base station transmits one layer). According to the claimed invention, a codeword specific configuration utilizes a pre-determined number of codewords (e.g., two codewords) for all transmission from multiple base stations. That is, a codeword specific configuration may incorporate multiple base stations in the transmission of the two codewords. In some cases, each base station communicates a single codeword at a time, and in some cases multiple TPs may jointly transmit a single codeword.

In some cases, various communication configurations may be dynamically indicated on a per-layer or per-codeword basis. These communication configurations may include one or more of a channel state information (CSI) power offset configuration, a CSI subframe set configuration, a codebook subset restriction, a rate matching configuration, and a quasi-co-location (QCL) indication. The indication of these communication configurations may enable a UE to perform channel feedback operations that are also layer or codeword specific. In some cases, the UE may report CSI to the base station regarding the quality of the signals received from each base station according to the layer or codeword specific configuration.

Aspects of the disclosure are initially described in the context of a wireless communication system. Further examples are then provided for wireless communications systems that support codeword specific and layer specific CoMP transmissions. Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that relate to enhanced CoMP operation.

<FIG> illustrates an example of a wireless communications system <NUM> in accordance with various aspects of the present disclosure. The wireless communications system <NUM> includes base stations <NUM>, UEs <NUM>, and a core network <NUM>. In some examples, the wireless communications system <NUM> may be a Long Term Evolution (LTE)/LTE-Advanced (LTE-A) network. Wireless communications system <NUM> may enable efficient CoMP transmissions using MIMO layer specific and codeword specific configurations.

Each base station <NUM> may provide communication coverage for a respective geographic coverage area <NUM>. Communication links <NUM> shown in wireless communications system <NUM> may include UL transmissions from a UE <NUM> to a base station <NUM>, or DL transmissions, from a base station <NUM> to a UE <NUM>. A UE <NUM> may also be referred to as a mobile station, a subscriber station, a remote unit, a wireless device, an access terminal (AT), a handset, a user agent, a client, or like terminology. A UE <NUM> may also be a cellular phone, a wireless modem, a handheld device, a personal computer, a tablet, a personal electronic device, an machine type communication (MTC) device, etc..

Wireless communications system <NUM> may employ CoMP transmissions in which two or more TPs may transmit data to a UE <NUM>. A TP may also be referred to as a base station <NUM> or a wireless node, and the terms may be used interchangeably. Such CoMP transmissions may use one or more CoMP schemes, including DPS in which different base stations transmit data to a UE <NUM> at different times, JT in which two or more base stations contemporaneously transmit data to a UE <NUM>, and CBF in which two or more base stations coordinate signal transmissions that reduce interference between the two or more base stations and/or with nodes in adjacent cells. CoMP includes techniques for dynamic coordination of transmission and reception by a number of base stations <NUM> to improve overall transmission quality for UEs <NUM> as well as increasing network and spectrum utilization.

Base stations <NUM> and UEs <NUM> may use multiple-input multiple-output (MIMO) techniques, where multiple transmit and receive antennas are used to transmit and receive signals, respectively. MIMO techniques use multiple antennas on the base stations <NUM> or multiple antennas on the UE <NUM> to take advantage of multipath environments to transmit multiple data streams. A UE <NUM> may report channel information (e.g., channel state information (CSI)) to the base station regarding the quality of the signal received at each antenna. The base station <NUM> may accordingly use a rank indicator (RI) that is based on an antenna configuration associated with the number of antennas used.

When transmitting a signal, the base station <NUM> may convert a bit sequence of a codeword into modulation symbols and assign the modulation symbols to one or more transmission layers. The number of transmission layers may be associated with the number of antennas used for communication between the base station <NUM> and UE <NUM>. For example, the number of layers may be less than or equal to the number of antennas, and a MIMO configuration may use at least two layers. While the techniques described herein reference the use and transmission of codewords, a codeword may also be referred to as a transport block (TB) and the terms may be interchangeable.

In some cases, MIMO transmissions may use a designated number of codewords that are associated with the number of layers. For example, two codewords may be used for transmissions of up to eight layers, such as a rank <NUM> transmission. In such cases, each codeword in the rank <NUM> transmission may include four layers. Each codeword may have a different modulation and coding scheme (MCS), new data indicator (NDI), and redundancy version (RV), but different layers corresponding to the same codeword may have the same MCS, NDI and/or RV. Similarly, hybrid automatic repeat request (HARQ) feedback may also be transmitted on a per-codeword basis, as opposed to a per-layer basis.

In some cases, wireless communications system <NUM> may utilize one or more enhanced component carriers (eCCs). An eCC may be characterized by one or more features including: flexible bandwidth, different transmission time intervals (TTIs), and modified control channel configuration. In some cases, an eCC may be associated with a carrier aggregation (CA) configuration or a dual connectivity configuration (e.g., when multiple serving cells have a suboptimal backhaul link). An eCC may also be configured for use in unlicensed spectrum or shared spectrum (e.g., where more than one operator is licensed to use the spectrum).

An eCC characterized by flexible bandwidth may include one or more segments that may be utilized by UEs <NUM> that are not capable of monitoring the whole bandwidth or prefer to use a limited bandwidth (e.g., to conserve power). In some cases, an eCC may utilize a different TTI length than other component carriers (CCs), which may include use of a reduced or variable symbol duration as compared with TTIs of the other CCs. The symbol duration may remain the same, in some cases, but each symbol may represent a distinct TTI. In some examples, an eCC may support transmissions using different TTI lengths. For example, some CCs may use uniform <NUM> millisecond (ms) TTIs, whereas an eCC may use a TTI length of a single symbol, a pair of symbols, or a slot. In some cases, a shorter symbol duration may also be associated with increased subcarrier spacing. In conjunction with the reduced TTI length, an eCC may utilize dynamic time division duplex (TDD) operation (i.e., it may switch from DL to UL operation for short bursts according to dynamic conditions.

Flexible bandwidth and variable TTIs may be associated with a modified control channel configuration (e.g., an eCC may utilize an ePDCCH for DL control information). For example, one or more control channels of an eCC may utilize frequency-division multiplexing (FDM) scheduling to accommodate flexible bandwidth use. Other control channel modifications include the use of additional control channels (e.g., for evolved multimedia broadcast multicast service (eMBMS) scheduling, or to indicate the length of variable length UL and DL bursts), or control channels transmitted at different intervals. An eCC may also include modified or additional hybrid automatic repeat request (HARQ) related control information.

In some cases, base station antennas may be located within one or more antenna arrays. One or more base station antennas or antenna arrays may be collocated at an antenna assembly, such as an antenna tower. A base station <NUM> may use multiple antennas or antenna arrays to conduct beamforming operations for directional communications with a UE <NUM>.

As described herein, a UE <NUM> may use MIMO layer specific and codeword specific communication configurations to communicate with at least one base station <NUM>. For example, multiple base stations <NUM> may be configured to provide CoMP transmissions to a UE <NUM>. The base stations <NUM> may transmit a set of communications configurations to the UE <NUM> that include at least one MIMO layer specific or codeword specific configuration. The UE <NUM> may also receive an indication of at least one communication configuration that may be used to perform MIMO layer specific or codeword specific channel operations. The UE <NUM> may then communicate with the base stations <NUM> using the communications configurations.

illustrates an example of a wireless communications system <NUM> for enhanced CoMP operation. Wireless communications system <NUM> may include one or more base stations <NUM> (e.g., base station <NUM>-a and base station <NUM>-b) and UE <NUM>, which may be examples of a base station <NUM> and a UE <NUM> described with reference to <FIG>, respectively. In some cases, base station <NUM>-a and base station <NUM>-b may provide communication coverage for geographic coverage areas <NUM>-a and <NUM>-b, respectively. As illustrated, in some cases, the geographic coverage areas <NUM>-a and <NUM>-b may partially overlap. Wireless communications system <NUM> may illustrate an example of MIMO layer specific CoMP transmissions where each base station is associated with a one or more MIMO layers.

Wireless communications system <NUM> may use a communications configuration that includes a MIMO layer specific configuration. That is, UE <NUM> may receive a set of communication configurations that include a MIMO layer specific configuration. The MIMO layer specific configuration may include transmitting different sets of layers <NUM> from different TPs or base stations, such as the base station <NUM>-a and the base station <NUM>-b. For example, base station <NUM>-a may transmit a first set of layers <NUM>-a to UE <NUM> and base station <NUM>-b may transmit a second set of layers <NUM>-b to UE <NUM>. The first set of layers <NUM>-a and second set of layers <NUM>-b may comprise a complete transmission to UE <NUM> in accordance with CoMP techniques described above.

Each layer in a set of layers <NUM> may come from one base station <NUM>. In some cases, the first set of layers <NUM>-a may include up to four different layers based on a number of antennas used, where the second set of layers <NUM>-b may similarly include up to four layers. The number of layers within the first set of layers <NUM>-a or the second set of layers <NUM>-b may depend on a configuration associated with the number of antennas used by base station <NUM>-a or base station <NUM>-b to communicate with UE <NUM>. In some cases, the number of base stations <NUM> used to transmit sets of layers <NUM> may be based on the MIMO layer specific configuration, and may correspond to the number of layers transmitted (e.g., eight base stations <NUM> may transmit eight layers <NUM>, where each base station <NUM> transmits one layer <NUM>). In some examples, a layer specific MCS, NDI, RV, or HARQ feedback may be used. For example, UE <NUM> may provide HARQ feedback for each layer included in a set of layers <NUM>.

UE <NUM> may report CSI feedback to the base station <NUM>-a and the base station <NUM>-b regarding the quality of the signals received based on the communications configuration. As will be discussed with reference to <FIG>, MIMO layer specific configurations and codeword specific configurations may be used to indicate various communication configurations to UE <NUM> for each layer or codeword.

<FIG> illustrates an example of a wireless communications system <NUM> for enhanced CoMP operation. Wireless communications system <NUM> may include one or more base stations <NUM> (e.g., base station <NUM>-a and base station <NUM>-b) and UE <NUM>, which may be examples of a base station <NUM> and a UE <NUM> described with reference to <FIG> and <FIG>. In some cases, base station <NUM>-a and base station <NUM>-b may provide communication coverage for geographic coverage areas <NUM>-a and <NUM>-b, respectively. As illustrated, in some cases, the geographic coverage areas <NUM>-a and <NUM>-b may partially overlap. Wireless communications system <NUM> may illustrate an example of codeword specific CoMP transmissions.

Wireless communications system <NUM> may use communication configurations that includes a codeword specific configuration. A codeword specific configuration may utilize a set number of codewords <NUM> (e.g., two codewords) for all transmission from multiple base stations <NUM> (e.g., base station <NUM>-a and base station <NUM>-b). That is, a codeword specific configuration may incorporate multiple base stations <NUM> in the transmission of two codewords <NUM>. For example, base station <NUM>-a may transmit a first codeword <NUM>-a, and base station <NUM>-b may transmit a second codeword <NUM>-b. Codeword <NUM>-a and codeword <NUM>-b may include multiple layers of modulated symbols.

In some cases, multiple base stations <NUM> may appear as a single base station to UE <NUM>. For example, a base station <NUM>-a may transmit first codeword <NUM>-a and another codeword <NUM> (not shown) may be transmitted by a combination of two base stations <NUM>. Through the use of codeword specific methods, MCS, NDI, RV and HARQ processes may not differ from systems that do not use codeword specific configurations. In some examples, the use of a MIMO layer specific and codeword specific configurations may be combined.

In some cases, various communication configurations may be dynamically indicated on a per-layer or a per-codeword basis. These communication configurations may include one or more of a CSI power offset configuration, a CSI subframe set configuration, a codebook subset restriction. According to the claimed invention, these communication configurations include a rate matching configuration and a quasi-co-location (QCL) indication. The indication of these communication configurations may enable the UE <NUM> to perform operations that are also layer or codeword specific. For example, a CSI power offset parameter may provide the UE <NUM> with a ratio indicating the amount of power between a CSI reference signal (CSI-RS) and a physical downlink shared channel (PDSCH) that UE <NUM> uses to compute CSI. In some cases, when this parameter is associated with a codeword or a layer, the UE <NUM> may use different power offset values for different codewords or layers when the CSI is transmitted to a base station <NUM>. Similarly, per-layer and per-codeword codebook restrictions may indicate to the UE <NUM> which restricted subset of ranks of a precoding matrix indicator that UE <NUM> may assume when providing CSI feedback, where the assumption may be per-layer or per-codeword instead of assuming a wide range of possible ranks and PMIs.

A CSI subframe set configuration may provide the UE <NUM> with two or more subframe sets, where each set may indicate a subset of subframes during which the UE <NUM> may perform CSI measurements and/or reporting. In some cases, when the CSI subframe set configuration is associated with MIMO layer specific or layer specific configurations, the UE <NUM> may use different subframe set configurations for different layers or codewords.

MIMO layer specific or codeword specific rate matching configurations provide the UE <NUM> with information about the received signals from base station <NUM>-a and base station <NUM>-b, where the rate matching configurations may include a multimedia broadcast multicast service (MBMS) single frequency network (MBSFN) indication, a configuration of CRS ports or CRS shifts, or one or more non-zero power (NZP) CSI-RS configurations. According to the claimed invention, the rate matching configurations include a starting symbol for PDSCH transmissions and an ending symbol for PDSCH. For example, a starting symbol for PDSCH may be indicated for a MIMO transmission, where a first layer may contain a first starting symbol and a second layer has a second starting symbol. Alternately, the indication may provide information that a first codeword has a starting symbol on a first layer, and a second codeword has a starting symbol on a second layer. In another example, a per-layer indication may enable different MBSFN configurations for different layers or different codewords.

In some examples, UE <NUM> may use one CSI process that is associated with two or more NZP CSI-RS configurations when at least one NZP CSI-RS configurations are used. Additionally, an indication of the ending symbol for PDSCH may be provided to the UE <NUM> on a per-layer or per codeword basis. That is, the indication may allow UE <NUM> to identify which symbol is the last symbol for a given transmission. In some cases, the indication of the ending PDSCH symbol may imply that the QCL indicator bit-width in downlink control information (DCI) may be increased (e.g., increase the bit-width to <NUM> bits). In some cases, a per-layer or per-codeword QCL configuration may be restricted to a configuration where a CRS, CSI-RS, and PDSCH demodulation reference signal (DMRS) may be assumed as quasi-co-located at least with respect to a frequency shift, a Doppler spread, a received timing, or a delay spread.

In some cases, the base stations <NUM>-a and <NUM>-b may have their own respective resource allocations. For example, the first base station <NUM>-a may use a first set of resource blocks (RBs), while the second base station <NUM>-b may use a second set of RBs, where the first set and the second set of RBs may be different (e.g., the RBs may not be equal). In some examples, base station <NUM>-a may use a first set of RBs, whereas base station <NUM>-b and a third base station <NUM> (not shown) may be combined to transmit a single codeword <NUM>, and may both use the same set of RBs. As a result, DCI may accommodate two or more information fields associated with resource allocation, such as a per-codeword or per-layer resource allocation information field.

In some cases, multi-hypotheses CSI feedback may be supported for a CSI process (or over multiple CSI-RS processes) if two or more CSI-RS resource configurations are used for the UE <NUM>. For example, two CSI-RS resource sets for a CSI process (e.g., CSI-RS resource set <NUM> and CSI-RS resource set <NUM>) may be configured for the UE <NUM>. The UE <NUM> may provide feedback based on at least resource set <NUM>, resource set <NUM>, and/or a combination of resource set <NUM> and resource set <NUM>.

In cases where the UE <NUM> may be served by only one base station <NUM> (e.g., base station <NUM>-a), the UE <NUM> may correspondingly report CSI for that base station <NUM>-a using either resource set <NUM> or resource set <NUM>. In some cases, the CSI interference measurement (CSI-IM) may be configured for a first base station <NUM> (e.g., base station <NUM>-a) and may capture the interference introduced by a second base station <NUM> (e.g., base station <NUM>-b). The CSI-IM configured for the second base station <NUM> may capture the interference introduced by the first base station <NUM>, or vice-versa.

In some cases, the UE <NUM> may be intended to be served by both a first base station <NUM> (e.g., base station <NUM>-a) and second base station <NUM> (e.g., base station <NUM>-b), and may accordingly report CSI for the base stations <NUM> using the combination of resource set <NUM> and resource set <NUM>. In this case, the UE <NUM> may refrain from assuming phase offsets between the two resource sets (e.g., resource set <NUM> and resource set <NUM>) and a CSI-IM configuration may capture interference from other cells. In some cases, the UE <NUM> may be configured with up to three CSI-IM configurations for a CSI-RS process, or over multiple CSI-RS processes.

In some examples, base stations <NUM>-a and <NUM>-b may each have two transmit antennas. Furthermore, UE <NUM> may also have more than one receive antenna (e.g., four receive antennas). The UE <NUM> may be configured with a first CSI-RS resource set and a second CSI-RS resource set, where each set is associated with two ports. In some cases, the RI/PMI for the first and second resource sets may be based on 2x4 configurations. RI/PMI for the combination of resource sets <NUM> and <NUM> may be separately reported for the base stations <NUM>-a and <NUM>-b, where each may be based on a 2x4 configuration. In some cases, the RI/PMI reported for each base station <NUM> may account for the impact of the other base station <NUM>.

In another example, the two base stations <NUM>-a and <NUM>-b may each have eight transmit antennas, and may communicate with the UE <NUM>, which may have eight receive antennas. The UE <NUM> may be configured with a CSI-RS resource set <NUM> and CSI-RS resource set <NUM>, each with eight ports. A RI/PMI for resource set <NUM> may be based on an 8x8 configuration and the RI/PMI for resource set <NUM> may also be based on an 8x8 configuration. The RI/PMI for the combination of both resource sets may be separately reported for each of the base stations <NUM>-a and <NUM>-b. Each CSI-RS resource set may be based on an 8x8 configuration, but may be limited to a rank <NUM> indication for each base station <NUM>. For example, the RI may indicate up to rank <NUM> for the first base station <NUM>-a and up to rank <NUM> for the second base station <NUM>-b. In this example, a total of six layers may be used, where a first codeword is mapped to four layers and a second codeword is mapped to two layers. In some cases, this mapping configuration may not be supported when both codewords are transmitted from the same base station <NUM> (e.g., base station <NUM>-a or base station <NUM>-b). In another example, the RI may indicate up to rank <NUM> for a first base station <NUM> (e.g., base station <NUM>-a) and up to rank <NUM> for a second base station <NUM> (e.g., base station <NUM>-b). As mentioned above, the RI/PMI reported for each base station <NUM> may account for the impact of the other base station <NUM>.

In some cases, a base station <NUM> may indicate a restricted RI for each base station <NUM> from a set of multiple base stations <NUM>, when the set of multiple base stations <NUM> are communicating as long as the total number of layers does not exceed the layers available according to an antenna configuration. In some cases, the restriction may enable the number of layers for each codeword to match the layers in a system that does not use MIMO layer specific or codeword specific configurations (e.g., layers <NUM>, <NUM>, <NUM>, and <NUM>).

In some cases, combinations of MIMO layers across multiple codewords transmitted from one or more base stations <NUM> may match the allowed combinations transmitted by a single base station <NUM>. That is, a set of combinations of MIMO layers across two codewords transmitted from different base stations <NUM> may be aligned with a set of allowed combinations for the two codewords when both codewords are transmitted from the same base station <NUM>. For example, if a combination of four layers for a first codeword and two layers for a second codeword may not be allowed when transmitted by a single base station <NUM>, then the same combination may not be allowed if two codewords are transmitted from different base stations <NUM>.

Different cells may use different special subframe configurations, where a DMRS pattern may be a function of a special subframe configuration. For example, a special subframe configuration of six downlink pilot time slot (DwPTS) symbols to six guard period (GP) symbols to two uplink pilot time slot (UpPTS) symbols (<NUM>:<NUM>:<NUM>), only DMRS symbols corresponding to symbols <NUM> and <NUM> are present (e.g., one strip DMRS pattern). In some cases the same DMRS pattern may be used across cells that communicate using CoMP. As a result, only special subframes of compatible DMRS patterns may be used in, for layer specific and codeword specific configurations. For example, a DwPTS pattern with <NUM> and <NUM> symbols may be used in a codeword or layer specific configuration, but not a DwPTS pattern with <NUM> and <NUM> symbols.

In some cases, there may be different DL/UL subframe configurations for MIMO layer specific configurations, and the set of cells involved in the MIMO layer specific configurations may be subframe dependent. For example, in a first subframe, a first cell may be a DL cell, while a second cell may be used for UL transmission. Additionally, in a second subframe, both cells may be used for DL transmissions for MIMO layer specific configurations.

In some cases, an enhanced physical downlink control channel (ePDCCH) may be configured with up to two resource sets. Each ePDCCH resource set may be linked with one of four PDSCH resource element (RE) mapping and quasi-co-location indicator (PQI) resource set configurations. If PQI configurations are layer or codeword specific, the ePDCCH resource set may be linked with one of the four PCI configurations of a particular layer or codeword. For example, the first layer or codeword of an associated PQI resource configuration may be used. In some cases, the link to ePDCCH resources may depend on how the PQI resource sets are configured. For example, up to eight PQI resource sets may be configured, where each set includes a pair of PQI configurations (e.g., set <NUM>: {PQI configuration <NUM>, PQI configuration <NUM>} and set <NUM> {PQI configuration <NUM>, PQI configuration <NUM>},. , set <NUM> {PQI configuration <NUM>, PQI configuration <NUM>}). In some cases, ePDCCH may, for example, be linked with the first configuration of set <NUM> and set <NUM>.

<FIG> illustrates an example of a process flow <NUM> for enhanced CoMP operation in accordance with various aspects of the present disclosure. Process flow <NUM> may include base stations <NUM>-a and <NUM>-b, and UE <NUM>, which may be examples of the corresponding devices described with reference to <FIG>.

At step <NUM>, a base station <NUM> may determine a set of communication configurations associated with base stations <NUM> (e.g., base station <NUM>-a and base station <NUM>-b), where at least one of the set of communication configurations is based on a MIMO layer specific communication or a codeword specific communication. The determination of the set of configurations may be completed by base station <NUM>-a, or base station <NUM>-b, or both. Additionally, the base stations <NUM> may be coordinated according to a CoMP configuration that includes a CBF mode or a DPS mode. According to the claimed invention, the base stations <NUM> are coordinated according to a CoMP configuration that includes a JT mode.

At step <NUM>, UE <NUM> may receive a set of communication configurations associated with the base stations <NUM> (e.g., base station <NUM>-a and base station <NUM>-b) where at least one of the set of communication configurations includes a MIMO layer specific configuration or a codeword specific configuration.

At step <NUM>, UE <NUM> may receive an indication of a communication configuration from the set of communication configurations received at step <NUM>. In some examples, the set of communication configurations and the indication may be transmitted by base station <NUM>-a, or base station <NUM>-b, or both. The communication configuration may include a CSI power offset configuration, a CSI subframe set configuration, a codebook restriction, a rate matching configuration, a QCL indication, or any combination thereof. In some cases, the rate matching configuration may include a starting symbol for PDSCH transmissions, a MBSFN indication, a CRS configuration, one or more NZP CSI-RS configurations, or any combination thereof.

At step <NUM>, UE <NUM> may identify a resource allocation for each of the plurality of base stations based on the communication configuration. In some cases, UE <NUM> may also identify a CSI-RS port configuration for one or more of the base stations <NUM> (e.g., base station <NUM>-a and base station <NUM>-b) based on the communication configuration.

At step <NUM>, the UE <NUM> may generate a CSI report for base station <NUM>-a and/or base station <NUM>-b, where the CSI report is based on the one or more base stations <NUM>. In some examples, the CSI-RS port configuration may be based on a number of receive ports for UE <NUM> and a number of transmit ports for the one or more base stations <NUM>. In some other cases, the UE <NUM> may generate an individual CSI report for the one or more TPs based on the communication configuration, where the communication configuration is based on communication with a single base station <NUM>, such as base station <NUM>-a. UE <NUM> may then transmit the individual CSI report to base station <NUM>-a. According to the claimed invention, UE <NUM> generates a combined CSI report for each of the base stations <NUM> (e.g., base station <NUM>-a and base station <NUM>-b) based on the communication configuration, where the communication configuration is based on communication with both base stations <NUM>. The UE <NUM> may then transmit the combined CSI report for each of the base stations <NUM>, as further described with reference to step <NUM>.

At step <NUM>, the UE <NUM> may communicate with one or more base stations <NUM> (e.g., either base station <NUM>-a or base station <NUM>-b, or both) using the communication configuration. In some cases, communicating with the one or more base stations <NUM> may comprise transmitting to the one or more base stations <NUM>, an individual CSI report, a combined CSI report, or both, which may be previously generated, for example, at step <NUM>. In some cases, communicating with the one or more base stations <NUM> is based on the resource allocation. In some other cases, communicating is based on the ePDCCH configuration. Additionally or alternatively, communicating may be based on the CoMP configuration.

<FIG> shows a block diagram of a wireless device <NUM> that supports enhanced CoMP operation in accordance with various aspects of the present disclosure. Wireless device <NUM> may be an example of aspects of a UE <NUM> and UE <NUM> described with reference to <FIG> and <FIG>. Wireless device <NUM> may include receiver <NUM>, UE CoMP manager <NUM> and transmitter <NUM>. Wireless device <NUM> may also include a processor. Each of these components may be in communication with each other.

The receiver <NUM> may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to enhanced CoMP operation, etc.). Information may be passed on to other components of the device. The receiver <NUM> may be an example of aspects of the transceiver <NUM> described with reference to <FIG>.

The UE CoMP manager <NUM> may receive a set of communication configurations associated with a set of base stations <NUM>, where at least one of the set of communication configurations includes a MIMO layer specific configuration or a codeword specific configuration, receive an indication of a communication configuration from the set of communication configurations, and communicate with at least one base station <NUM> of the set of base stations <NUM> using the communication configuration. The UE CoMP manager <NUM> may also be an example of aspects of the UE CoMP manager <NUM> described with reference to <FIG>.

The transmitter <NUM> may transmit signals received from other components of wireless device <NUM>. In some examples, the transmitter <NUM> may be collocated with a receiver in a transceiver module. The transmitter <NUM> may include a single antenna, or it may include a plurality of antennas.

<FIG> shows a block diagram of a wireless device <NUM> that supports enhanced CoMP operation in accordance with various aspects of the present disclosure. Wireless device <NUM> may be an example of aspects of a wireless device <NUM> or a UE <NUM> described with reference to <FIG> and <FIG>. Wireless device <NUM> may include receiver <NUM>, UE CoMP manager <NUM> and transmitter <NUM>. Wireless device <NUM> may also include a processor. Each of these components may be in communication with each other.

The receiver <NUM> may receive information which may be passed on to other components of the device. The receiver <NUM> may also perform the functions described with reference to the receiver <NUM> of <FIG>. The receiver <NUM> may be an example of aspects of the transceiver <NUM> described with reference to <FIG>.

The UE CoMP manager <NUM> may be an example of aspects of UE CoMP manager <NUM> described with reference to <FIG>. The UE CoMP manager <NUM> may include communication configuration component <NUM>, configuration indication component <NUM> and coordinated communication component <NUM>. The UE CoMP manager <NUM> may be an example of aspects of the UE CoMP manager <NUM> described with reference to <FIG>.

The communication configuration component <NUM> may receive a set of communication configurations associated with a set of base stations, where at least one of the set of communication configurations includes a MIMO layer specific configuration or a codeword specific configuration. In some cases, the rate matching configuration includes a starting symbol for PDSCH transmissions, an ending symbol for PDSCH transmissions, an MBSFN indication, a CRS configuration, one or more NZP CSI-RS configurations, or any combination thereof.

In some cases, the communication configuration includes an UL configuration and a DL configuration. In some cases, the communication configuration includes an ePDCCH configuration, and where the communicating is based on the ePDCCH configuration. In some cases, the ePDCCH configuration includes one or more ePDCCH resource sets associated with the MIMO layer specific configuration or the codeword specific configuration.

In some cases, the set of base stations are coordinated according to a CoMP configuration that includes a CBF mode, a DPS mode, or a JT mode, and where communicating is based on the CoMP configuration. In some cases, the communication configuration includes a CSI power offset configuration, a CSI subframe set configuration, a codebook restriction, a rate matching configuration, a QCL indication, or any combination thereof.

The configuration indication component <NUM> may receive an indication of a communication configuration from the set of communication configurations. The coordinated communication component <NUM> may communicate with at least one base station of the set of base stations using the communication configuration.

The transmitter <NUM> may transmit signals received from other components of wireless device <NUM>. In some examples, the transmitter <NUM> may be collocated with a receiver in a transceiver module. The transmitter <NUM> may utilize a single antenna, or it may utilize a plurality of antennas.

<FIG> shows a block diagram of a UE CoMP manager <NUM> which may be an example of the corresponding component of wireless device <NUM> or wireless device <NUM>. That is, UE CoMP manager <NUM> may be an example of aspects of UE CoMP manager <NUM> or UE CoMP manager <NUM> described with reference to <FIG> and <FIG>. The UE CoMP manager <NUM> may also be an example of aspects of the UE CoMP manager <NUM> described with reference to <FIG>.

The UE CoMP manager <NUM> may include resource allocation component <NUM>, CSI-RS port configuration component <NUM>, CSI report component <NUM>, special subframe component <NUM>, configuration indication component <NUM>, communication configuration component <NUM> and coordinated communication component <NUM>. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses).

The resource allocation component <NUM> may identify a resource allocation for each of the set of base stations based on the communication configuration, where the communicating is based on the resource allocation. The CSI-RS port configuration component <NUM> may identify a CSI-RS port configuration for the at least one base station based on the communication configuration. In some cases, the CSI-RS port configuration is based on a number of receive ports for a UE and a number of transmit ports for the at least one base station.

The CSI report component <NUM> may transmit a CSI report to the at least one base station, where the CSI report is based on the CSI-RS port configuration and the set of base stations, generate an individual CSI report for the at least one base station based on the communication configuration, where the communication configuration is based on communication with a single base station, transmit the individual CSI report, generate a combined CSI report for each of the set of base stations based on the communication configuration, where the communication configuration is based on communication with the set of base stations, and transmit the combined CSI report for each of the set of base stations.

The special subframe component <NUM> may identify a special subframe configuration for each of the set base stations based on the communication configuration, where the communicating is based on the special subframe configuration. In some cases, the special subframe configuration includes a DMRS pattern, and where the communicating is based on the DMRS pattern. The configuration indication component <NUM> may receive an indication of a communication configuration from the set of communication configurations.

The communication configuration component <NUM> may receive a set of communication configurations associated with a set of base stations, where at least one of the set of communication configurations includes a MIMO layer specific configuration or a codeword specific configuration. The coordinated communication component <NUM> may communicate with at least one base station of the set of base stations using the communication configuration.

<FIG> shows a diagram of a system <NUM> including a device that supports enhanced CoMP operation in accordance with various aspects of the present disclosure. For example, system <NUM> may include UE <NUM>, which may be an example of a wireless device <NUM>, a wireless device <NUM>, or a UE <NUM> as described with reference to <FIG>, and <FIG> through <NUM>.

UE <NUM> may also include UE CoMP manager <NUM>, memory <NUM>, processor <NUM>, transceiver <NUM>, antenna <NUM> and MIMO module <NUM>. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses <NUM>). The UE CoMP manager <NUM> may be an example of a UE CoMP manager as described with reference to <FIG>.

The memory <NUM> may include random access memory (RAM) and read only memory (ROM). The memory <NUM> may store computer-readable, computer-executable software including instructions that, when executed, cause the processor to perform various functions described herein (e.g., enhanced CoMP operation, etc.). In some cases, the software <NUM> may not be directly executable by the processor but may cause a computer (e.g., when compiled and executed) to perform functions described herein. The processor <NUM> may include an intelligent hardware device, (e.g., a central processing unit (CPU), a microcontroller, an application specific integrated circuit (ASIC), etc.).

The transceiver <NUM> may communicate bi-directionally, via one or more antennas, wired, or wireless links, with one or more networks, as described above. For example, the transceiver <NUM> may communicate bi-directionally with a base station <NUM> or a UE <NUM>. MIMO module <NUM> may enable MIMO operations such as communicating using multiple logical communications layers as described above.

<FIG> shows a block diagram of a wireless device <NUM> that supports enhanced CoMP operation in accordance with various aspects of the present disclosure. Wireless device <NUM> may be an example of aspects of a base station <NUM> described with reference to <FIG> and <FIG>. Wireless device <NUM> may include receiver <NUM>, base station CoMP manager <NUM> and transmitter <NUM>. Wireless device <NUM> may also include a processor. Each of these components may be in communication with each other.

The base station CoMP manager <NUM> may transmit a set of communication configurations associated with a set of base stations, where at least one of the set of communication configurations is based on a MIMO layer specific communication or a codeword specific communication, transmit an indication of a communication configuration from the set of communication configurations, and communicate with a UE using the communication configuration. The base station CoMP manager <NUM> may also be an example of aspects of the base station CoMP manager <NUM> described with reference to <FIG>.

<FIG> shows a block diagram of a wireless device <NUM> that supports enhanced CoMP operation in accordance with various aspects of the present disclosure. Wireless device <NUM> may be an example of aspects of a wireless device <NUM> or a base station <NUM> described with reference to <FIG>, <FIG> and <FIG>. Wireless device <NUM> may include receiver <NUM>, base station CoMP manager <NUM> and transmitter <NUM>. Wireless device <NUM> may also include a processor. Each of these components may be in communication with each other.

The base station CoMP manager <NUM> may be an example of aspects of base station CoMP manager <NUM> described with reference to <FIG>. The base station CoMP manager <NUM> may include communication configuration component <NUM>, configuration indication component <NUM> and coordinated communication component <NUM>. The base station CoMP manager <NUM> may be an example of aspects of the base station CoMP manager <NUM> described with reference to <FIG>.

The communication configuration component <NUM> may transmit a set of communication configurations associated with a set of base stations, where at least one of the set of communication configurations is based on a MIMO layer specific communication or a codeword specific communication. In some cases, the communication configuration includes a CSI power offset configuration, a CSI subframe set configuration, a codebook restriction, a rate matching configuration, a QCL indication, or any combination thereof. In some cases, the rate matching configuration includes a starting symbol for PDSCH transmissions, an ending symbol for PDSCH transmissions, an MBSFN indication, a CRS configuration, one or more NZP CSI-RS)configurations, or any combination thereof.

In some cases, the communication configuration includes a UL configuration and a DL configuration. In some cases, the communication configuration includes ePDCCH configuration, and where the communicating is based on the ePDCCH configuration. In some cases, the set of base stations are coordinated according to a CoMP configuration that includes a CBF mode, a DPS mode, or a JT mode, and where communicating is based on the CoMP configuration.

The configuration indication component <NUM> may transmit an indication of a communication configuration from the set of communication configurations. The coordinated communication component <NUM> may communicate with a UE using the communication configuration.

<FIG> shows a block diagram of a base station CoMP manager <NUM> which may be an example of the corresponding component of wireless device <NUM> or wireless device <NUM>. That is, base station CoMP manager <NUM> may be an example of aspects of base station CoMP manager <NUM> or base station CoMP manager <NUM> described with reference to <FIG> and <FIG>. The base station CoMP manager <NUM> may also be an example of aspects of the base station CoMP manager <NUM> described with reference to <FIG>.

The base station CoMP manager <NUM> may include resource allocation component <NUM>, CSI-RS port configuration component <NUM>, CSI report component <NUM>, special subframe component <NUM>, configuration indication component <NUM>, communication configuration component <NUM> and coordinated communication component <NUM>. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses).

The resource allocation component <NUM> may identify a resource allocation for each of the set of base stations based on the communication configuration, where the communicating is based on the resource allocation. The CSI-RS port configuration component <NUM> may identify a CSI-RS port configuration based on the communication configuration. In some cases, the CSI-RS port configuration is based on a number of receive ports for a UE and a number of transmit ports.

The CSI report component <NUM> may receive a CSI report based on the CSI-RS port configuration and set of base stations, receive an individual CSI report based on the communication configuration, where the communication configuration is based on communication between a UE and a single base station, and receive a combined CSI report based on the communication configuration, where the communication configuration is based on communication with the set of base stations.

The special subframe component <NUM> may identify a special subframe configuration based on the communication configuration, where the communicating is based on the special subframe configuration. In some cases, the special subframe configuration includes a DMRS pattern, and where the communicating is based on the DMRS configuration. The configuration indication component <NUM> may transmit an indication of a communication configuration from the set of communication configurations.

The communication configuration component <NUM> may transmit a set of communication configurations associated with a set of base stations, where at least one of the set of communication configurations is based on a MIMO layer specific communication or a codeword specific communication. The coordinated communication component <NUM> may communicate with a UE using the communication configuration.

<FIG> shows a diagram of a wireless system <NUM> including a device that supports enhanced CoMP operation in accordance with various aspects of the present disclosure. For example, system <NUM> may include base station <NUM>-a, which may be an example of a wireless device <NUM>, a wireless device <NUM>, or a base station <NUM> as described with reference to <FIG>, and <FIG>. Base station <NUM>-a may also include components for bi-directional voice and data communications including components for transmitting communications and components for receiving communications. For example, base station <NUM>-a may communicate bi-directionally with one or more UEs <NUM> (e.g., UE <NUM>-a and UE <NUM>-b).

Base station <NUM>-a may also include base station CoMP manager <NUM>, memory <NUM>, processor <NUM>, transceiver <NUM>, antenna <NUM>, base station communications module <NUM> and network communications module <NUM>. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses <NUM>). The base station CoMP manager <NUM> may be an example of a base station CoMP manager as described with reference to <FIG>.

The memory <NUM> may include RAM and ROM. The memory <NUM> may store computer-readable, computer-executable software including instructions that, when executed, cause the processor to perform various functions described herein (e.g., enhanced CoMP operation, etc.). In some cases, the software <NUM> may not be directly executable by the processor but may cause a computer (e.g., when compiled and executed) to perform functions described herein. The processor <NUM> may include an intelligent hardware device, (e.g., a CPU, a microcontroller, an ASIC, etc.).

The transceiver <NUM> may communicate bi-directionally, via one or more antennas, wired, or wireless links, with one or more networks, as described above. For example, the transceiver <NUM> may communicate bi-directionally with a base station <NUM> or a UE <NUM>.

The base station communications module <NUM> may manage communications with other base stations <NUM>, and may include a controller or scheduler for controlling communications with UEs <NUM> in cooperation with other base stations <NUM>. For example, the base station communications module <NUM> may coordinate scheduling for transmissions to UEs <NUM> for various interference mitigation techniques such as beamforming or joint transmission. In some examples, base station communications module <NUM> may provide an X2 interface <NUM> within an LTE/LTE-A wireless communication network technology to provide communication between one or more other base stations <NUM> (e.g., base station <NUM>-b, base station <NUM>-c, or both). In some cases, X2 interface <NUM> may be an example of a backhaul link <NUM> as described with reference to <FIG>.

The network communications module <NUM> may manage communications with the core network <NUM> (e.g., via one or more wired backhaul links <NUM>). In some cases, the core network <NUM> and the backhaul link <NUM> may examples of a core network <NUM> and a backhaul link <NUM> as described with reference to <FIG>. For example, the network communications module <NUM> may manage the transfer of data communications for client devices, such as one or more UEs <NUM>.

<FIG> shows a flowchart illustrating a method <NUM> for enhanced CoMP operation in accordance with various aspects of the present disclosure. The operations of method <NUM> may be implemented by a device such as a UE <NUM> or a UE <NUM>, or their components, as described with reference to <FIG> and <FIG>. For example, the operations of method <NUM> may be performed by the UE CoMP manager as described herein. In some examples, the UE <NUM> may execute a set of codes to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the UE <NUM> may perform aspects of the functions described below using special-purpose hardware.

At block <NUM>, the UE <NUM> may receive a set of communication configurations associated with a set of base stations, where at least one of the set of communication configurations includes a MIMO layer specific configuration or a codeword specific configuration as described above with reference to <FIG>. In certain examples, the operations of block <NUM> may be performed by the communication configuration component as described with reference to <FIG> and <FIG>.

At block <NUM>, the UE <NUM> may receive an indication of a communication configuration from the set of communication configurations as described above with reference to <FIG>. In certain examples, the operations of block <NUM> may be performed by the configuration indication component as described with reference to <FIG> and <FIG>.

At block <NUM>, the UE <NUM> may communicate with at least one base station of the set of base stations using the communication configuration as described above with reference to <FIG>. In certain examples, the operations of block <NUM> may be performed by the coordinated communication component as described with reference to <FIG> and <FIG>.

At block <NUM>, the UE <NUM> may identify a resource allocation for each of the set of base stations based on the communication configuration, where the communicating is based on the resource allocation as described above with reference to <FIG>. In certain examples, the operations of block <NUM> may be performed by the resource allocation component as described with reference to <FIG> and <FIG>.

At block <NUM>, the UE <NUM> may identify a CSI-RS port configuration for at least one base station based on the communication configuration as described above with reference to <FIG>. In certain examples, the operations of block <NUM> may be performed by the CSI-RS port configuration component as described with reference to <FIG> and <FIG>.

At block <NUM>, the UE <NUM> may transmit a CSI report to at least one base station, where the CSI report is based on the CSI-RS port configuration and the set of base stations as described above with reference to <FIG>. In certain examples, the operations of block <NUM> may be performed by the CSI report component as described with reference to <FIG> and <FIG>.

At block <NUM>, the UE <NUM> may generate an individual CSI report for at least one base station based on the communication configuration, where the communication configuration is based on communication with a single base station as described above with reference to <FIG>. In certain examples, the operations of block <NUM> may be performed by the CSI report component as described with reference to <FIG> and <FIG>.

At block <NUM>, the UE <NUM> may transmit the individual CSI report as described above with reference to <FIG>. In certain examples, the operations of block <NUM> may be performed by the CSI report component as described with reference to <FIG> and <FIG>.

At block <NUM>, the UE <NUM> may generate a combined CSI report for each of the set of base stations based on the communication configuration, where the communication configuration is based on communication with the set of base stations as described above with reference to <FIG>. In certain examples, the operations of block <NUM> may be performed by the CSI report component as described with reference to <FIG> and <FIG>.

At block <NUM>, the UE <NUM> may transmit the combined CSI report for each of the set of base stations as described above with reference to <FIG>. In certain examples, the operations of block <NUM> may be performed by the CSI report component as described with reference to <FIG> and <FIG>.

<FIG> shows a flowchart illustrating a method <NUM> for enhanced CoMP operation in accordance with various aspects of the present disclosure. The operations of method <NUM> may be implemented by a device such as a UE <NUM> or a UE <NUM>, or their components, as described with reference to <FIG> and <FIG>. For example, the operations of method <NUM> may be performed by the UE CoMP manager as described herein. In some examples, the UE <NUM> may execute a set of codes to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the UE <NUM> may perform aspects the functions described below using special-purpose hardware.

At block <NUM>, the UE <NUM> may identify a special subframe configuration for each of the set base stations based on the communication configuration, where the communicating is based on the special subframe configuration as described above with reference to <FIG>. In certain examples, the operations of block <NUM> may be performed by the special subframe component as described with reference to <FIG> and <FIG>.

At block <NUM>, the UE <NUM> may communicate with at least one base station of the set of base stations using the communication configuration and the special subframe configuration as described above with reference to <FIG>. In certain examples, the operations of block <NUM> may be performed by the coordinated communication component as described with reference to <FIG> and <FIG>.

<FIG> shows a flowchart illustrating a method <NUM> for enhanced CoMP operation in accordance with various aspects of the present disclosure. The operations of method <NUM> may be implemented by a device such as a base station <NUM> or its components as described with reference to <FIG>. For example, the operations of method <NUM> may be performed by the base station CoMP manager as described herein. In some examples, the base station <NUM> may execute a set of codes to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the base station <NUM> may perform aspects of the functions described below using special-purpose hardware.

At block <NUM>, the base station <NUM> may transmit a set of communication configurations associated with a set of base stations, where at least one of the set of communication configurations is based on a MIMO layer specific communication or a codeword specific communication as described above with reference to <FIG>. In certain examples, the operations of block <NUM> may be performed by the communication configuration component as described with reference to <FIG> and <FIG>.

At block <NUM>, the base station <NUM> may transmit an indication of a communication configuration from the set of communication configurations as described above with reference to <FIG>. In certain examples, the operations of block <NUM> may be performed by the configuration indication component as described with reference to <FIG> and <FIG>.

At block <NUM>, the base station <NUM> may communicate with a UE using the communication configuration as described above with reference to <FIG>. In certain examples, the operations of block <NUM> may be performed by the coordinated communication component as described with reference to <FIG> and <FIG>.

It should be noted that these methods describe possible implementation, and that the operations and the steps may be rearranged or otherwise modified such that other implementations are possible. In some examples, aspects from two or more of the methods may be combined. For example, aspects of each of the methods may include steps or aspects of the other methods, or other steps or techniques described herein. Thus, aspects of the disclosure may provide for enhanced CoMP operation.

The description herein is provided to enable a person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not to be limited to the examples and designs described herein but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.

Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical (physical) locations. Also, as used herein, including in the claims, "or" as used in a list of items (for example, a list of items prefaced by a phrase such as "at least one of" or "one or more") indicates an inclusive list such that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C).

By way of example, and not limitation, non-transitory computer-readable media can include RAM, ROM, electrically erasable programmable read only memory (EEPROM), compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that can be used to carry or store desired program code means in the form of instructions or data structures and that can be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor.

Techniques described herein may be used for various wireless communications systems such as CDMA, TDMA, FDMA, OFDMA, single carrier frequency division multiple access (SC-FDMA), and other systems. The terms "system" and "network" are often used interchangeably. IS-<NUM> Releases <NUM> and A are commonly referred to as CDMA2000 1X, 1X, etc. IS-<NUM> (TIA-<NUM>) is commonly referred to as CDMA2000 1xEV-DO, High Rate Packet Data (HRPD), etc. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. A TDMA system may implement a radio technology such as (Global System for Mobile communications (GSM)).

An OFDMA system may implement a radio technology such as Ultra Mobile Broadband (UMB), Evolved UTRA (E-UTRA), IEEE <NUM>, IEEE <NUM> (WiMAX), IEEE <NUM>, Flash-OFDM, etc. UTRA and E-UTRA are part of Universal Mobile Telecommunications system (Universal Mobile Telecommunications System (UMTS)). 3GPP LTE and LTE-advanced (LTE-A) are new releases of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-a, and GSM are described in documents from an organization named "3rd Generation Partnership Project" (3GPP). The description herein, however, describes an LTE system for purposes of example, and LTE terminology is used in much of the description above, although the techniques are applicable beyond LTE applications.

In LTE/LTE-A networks, including networks described herein, the term eNB may be generally used to describe the base stations. The wireless communications system or systems described herein may include a heterogeneous LTE/LTE-A network in which different types of eNBs provide coverage for various geographical regions. For example, each eNB or base station may provide communication coverage for a macro cell, a small cell, or other types of cell. The term "cell" is a 3GPP term that can be used to describe a base station, a carrier or component carrier (CC) associated with a base station, or a coverage area (e.g., sector, etc.) of a carrier or base station, depending on context.

Base stations may include or may be referred to by those skilled in the art as a base transceiver station, a radio base station, an access point (AP), a radio transceiver, a NodeB, eNodeB (eNB), Home NodeB, a Home eNodeB, or some other suitable terminology. The geographic coverage area for a base station may be divided into sectors making up only a portion of the coverage area. The wireless communications system or systems described herein may include base stations of different types (e.g., macro or small cell base stations). The UEs described herein may be able to communicate with various types of base stations and network equipment including macro eNBs, small cell eNBs, relay base stations, and the like. There may be overlapping geographic coverage areas for different technologies. In some cases, different coverage areas may be associated with different communication technologies. In some cases, the coverage area for one communication technology may overlap with the coverage area associated with another technology. Different technologies may be associated with the same base station, or with different base stations.

A small cell is a lower-powered base stations, as compared with a macro cell, that may operate in the same or different (e.g., licensed, unlicensed, etc.) frequency bands as macro cells. An eNB may support one or multiple (e.g., two, three, four, and the like) cells (e.g., CCs). A UE may be able to communicate with various types of base stations and network equipment including macro eNBs, small cell eNBs, relay base stations, and the like.

The DL transmissions described herein may also be called forward link transmissions while the UL transmissions may also be called reverse link transmissions. Each communication link described herein including, for example, wireless communications system <NUM> and <NUM> of <FIG> and <FIG> may include one or more carriers, where each carrier may be a signal made up of multiple sub-carriers (e.g., waveform signals of different frequencies). Each modulated signal may be sent on a different sub-carrier and may carry control information (e.g., reference signals, control channels, etc.), overhead information, user data, etc. The communication links described herein (e.g., communication links <NUM> of <FIG>) may transmit bidirectional communications using frequency division duplex (FDD) (e.g., using paired spectrum resources) or TDD operation (e.g., using unpaired spectrum resources). Frame structures may be defined for FDD (e.g., frame structure type <NUM>) and TDD (e.g., frame structure type <NUM>).

Thus, aspects of the disclosure may provide for enhanced CoMP operation. It should be noted that these methods describe possible implementations, and that the operations and the steps may be rearranged or otherwise modified such that other implementations are possible. In some examples, aspects from two or more of the methods may be combined.

The various illustrative blocks and modules described in connection with the disclosure herein may be implemented or performed with a general-purpose processor, a digital signal processor (DSP), an ASIC, an field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. Thus, the functions described herein may be performed by one or more other processing units (or cores), on at least one integrated circuit (IC). In various examples, different types of ICs may be used (e.g., Structured/Platform ASICs, an FPGA, or another semi-custom IC), which may be programmed in any manner known in the art. The functions of each unit may also be implemented, in whole or in part, with instructions embodied in a memory, formatted to be executed by one or more general or application-specific processors.

Claim 1:
A method (<NUM>) of wireless communication for enhanced coordinated multipoint operation, CoMP, characterized by comprising:
receiving (<NUM>) a set of communication configurations associated with a plurality of base stations, wherein the plurality of base stations are coordinated according to a CoMP configuration that comprises a joint transmission, JT, mode, wherein a communication configuration of the set of communication configurations comprises a codeword specific configuration utilizing a pre-determined number of codewords for all transmissions from the plurality of base stations, the codeword specific configuration comprising a quasi-colocation, QCL, indication and a rate matching configuration on a per-codeword basis, the rate matching configuration comprising a starting symbol and an ending symbol for physical downlink shared channel, PDSCH, transmissions;
receiving (<NUM>) an indication of the communication configuration from the set of communication configurations; and
communicating (<NUM>) with the plurality of base stations using the communication configuration; further comprising:
generating (<NUM>) a combined CSI report for each of the plurality of base stations based at least in part on the communication configuration, wherein the communication configuration is based on communication with the plurality of base stations; and transmitting (<NUM>) the combined CSI report for each of the plurality of base stations.