CSI-RS design with dynamic subframe structure

Abstract

The present application relates to CSI-RS design with dynamic subframe structure. Methods, systems, and devices for wireless communication are described. Base stations and user equipment (UE) may use subframe configurations that include dynamically scheduled channel state information reference signal (CSI-RS) symbols. For example, a base station may identify a subframe configuration that includes one or more CSI-RS symbol sets for a subframe. The base station may indicate to the UE whether the CSI-RS symbol set may be enabled or disabled during the subframe. The UE may receive multiple CSI-RS at different locations within the subframe as indicated by the base station, and transmit CSI feedback to the base station based on at least one of the received CSI-RS. In some examples, multiple base stations may coordinate the use of subframe configurations that include CSI-RS symbols that may be enabled or disabled.

Description

[0001] This application is a divisional application of the invention patent application entitled “CSI-RS design with dynamic subframe structure” with application date of April 21, 2017 and application number 201780030198.X.

[0002] Cross-references

[0003] This patent application claims priority to U.S. Patent Application No. 15 / 372,916, entitled “CSI-RS Design With Dynamic Subframe Structure,” filed by Islam et al. on December 8, 2016, and U.S. Provisional Patent Application No. 62 / 338,500, entitled “CSI-RS Design With Dynamic Subframe Structure,” filed by Islam et al. on May 18, 2016, each of which is assigned to the assignee of this application.

[0004] background

[0005] The following relates generally to wireless communications, and more particularly to CSI-RS design with dynamic subframe structure.

[0006] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, messaging, broadcast, and the like. These systems may be capable of supporting communication with multiple users by sharing available system resources (e.g., time, frequency, and power). 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 (e.g., long term evolution (LTE) systems). A wireless multiple-access communication system may include several base stations, each of which simultaneously supports communication for multiple communication devices, which may be further referred to as user equipment (UE).

[0007] The base station may transmit a reference signal to the UE during a subframe to assist in channel estimation and channel quality feedback. In some cases, similar transmissions by nearby wireless devices or neighboring base stations may overlap with the signal received by the UE. This may reduce the effectiveness of channel estimation and additional scheduling by the base station, which may result in signal degradation and reduced throughput.

[0008] Overview

[0009] Base stations and user equipment (UE) may use subframe configurations that include dynamically scheduled channel state information reference signal (CSI-RS) symbols. For example, a base station may identify a subframe configuration that includes one or more CSI-RS symbol sets for a subframe. The base station may indicate to the UE whether a CSI-RS symbol set may be enabled or disabled during a subframe. The UE may receive multiple CSI-RSs at different locations within a subframe as indicated by the base station, and transmit CSI feedback to the base station based on at least one of the received CSI-RSs. In some examples, multiple base stations may coordinate the use of subframe configurations that include CSI-RS symbols that may be enabled or disabled.

[0010] A method of wireless communication is described. The method may include receiving an indication that one or more of a plurality of channel state information reference signal (CSI-RS) symbol sets are to be enabled or disabled, and receiving one or more CSI-RS at corresponding positions in a subframe according to the indication.

[0011] An apparatus for wireless communication is described. The apparatus may include means for receiving an indication that one or more of a plurality of channel state information reference signal (CSI-RS) symbol sets are to be enabled or disabled, and means for receiving one or more CSI-RS at corresponding positions in a subframe according to the indication.

[0012] Another apparatus for wireless communication is described. The apparatus may include a processor, a memory in electronic communication with the processor, and instructions stored in the memory. The instructions are operable to cause the processor to: receive an indication that one or more of a plurality of channel state information reference signal (CSI-RS) symbol sets are to be enabled or disabled, and receive one or more CSI-RS at corresponding positions in a subframe in accordance with the indication.

[0013] A non-transitory computer-readable medium for wireless communication is described. The non-transitory computer-readable medium may include instructions operable to cause a processor to perform the following operations: receiving an indication that one or more of a plurality of channel state information reference signal (CSI-RS) symbol sets are to be enabled or disabled, and receiving one or more CSI-RS at corresponding positions in a subframe according to the indication.

[0014] Some examples of the above-described methods, apparatus (equipment) or non-transitory computer-readable media may further include processes, features, devices or instructions for transmitting one or more instances of CSI feedback based at least in part on at least one of the CSI-RSs.

[0015] In some examples of the foregoing methods, apparatuses (equipment), or non-transitory computer-readable media, the CSI feedback includes feedback based on each of the one or more sets.

[0016] In some examples of the above methods, apparatuses (equipment) or non-transitory computer-readable media, CSI feedback is generated based on each enabled CSI-RS symbol set in a plurality of CSI-RS symbol sets.

[0017] In some examples of the foregoing method, apparatus (equipment), or non-transitory computer-readable medium, the multiple CSI-RS symbol sets include two non-overlapping CSI-RS symbol sets.

[0018] In some examples of the foregoing method, apparatus (equipment), or non-transitory computer-readable medium, a set of the plurality of CSI-RS symbol sets includes symbols located at the last two symbols of the subframe.

[0019] In some examples of the above-mentioned method, device (equipment) or non-transitory computer-readable medium, the indication indicates that a set of CSI-RS codewords located in the last two codewords of the subframe will be disabled and a different set of CSI-RS codewords located in the data portion of the subframe will be enabled.

[0020] In some examples of the above method, apparatus (equipment), or non-transitory computer-readable medium, the multiple CSI-RS symbol sets include a CSI-RS symbol set including two symbols located before the last two symbols of the subframe.

[0021] In some examples of the foregoing methods, apparatus (equipment), or non-transitory computer-readable media, the indication is dynamically signaled via a control channel.

[0022] In some examples of the above method, apparatus (equipment) or non-transitory computer-readable medium, a CSI-RS is received on a millimeter wave (mmW) frequency resource.

[0023] A method of wireless communication is described. The method may include transmitting an indication that one or more of a plurality of channel state information reference signal (CSI-RS) symbol sets are to be enabled or disabled, and transmitting one or more CSI-RS at corresponding positions in a subframe according to the indication.

[0024] An apparatus for wireless communication is described. The apparatus may include means for transmitting an indication that one or more of a plurality of channel state information reference signal (CSI-RS) symbol sets are to be enabled or disabled, and means for transmitting one or more CSI-RS at corresponding positions in a subframe according to the indication.

[0025] Another apparatus for wireless communication is described. The apparatus may include a processor, a memory in electronic communication with the processor, and instructions stored in the memory. The instructions are operable to cause the processor to: transmit an indication that one or more of a plurality of CSI-RS symbol sets are to be enabled or disabled, and transmit one or more CSI-RS at corresponding positions in a subframe according to the indication.

[0026] A non-transitory computer-readable medium for wireless communication is described. The non-transitory computer-readable medium may include instructions operable to cause a processor to perform the following operations: transmitting an indication that one or more of a plurality of CSI-RS symbol sets are to be enabled or disabled, and transmitting one or more CSI-RS at corresponding positions in a subframe according to the indication.

[0027] Some examples of the methods, apparatuses (equipment) or non-transitory computer-readable media described above may further include a process, feature, device or instruction for receiving one or more instances of CSI feedback based at least in part on the indication. In some examples of the above methods, apparatuses (equipment) or non-transitory computer-readable media, the CSI feedback includes feedback based on each of one or more sets. In some examples of the above methods, apparatuses (equipment) or non-transitory computer-readable media, the CSI feedback is generated based on all enabled CSI-RS symbol sets in the CSI-RS symbol set.

[0028] In some examples of the above method, apparatus (equipment) or non-transitory computer-readable medium, the multiple CSI-RS symbol sets include two CSI-RS symbol sets. In some examples of the above method, apparatus (equipment) or non-transitory computer-readable medium, the multiple CSI-RS symbol sets include CSI-RS symbol sets located in the last two symbols of the subframe.

[0029] In some examples of the above-mentioned method, device (equipment) or non-transitory computer-readable medium, the indication indicates that a set of CSI-RS codewords located in the last two codewords of the subframe will be disabled and a different set of CSI-RS codewords located in the data portion of the subframe will be enabled.

[0030] In some examples of the above methods, apparatuses (equipment) or non-transitory computer-readable media, the plurality of CSI-RS symbol sets include a CSI-RS symbol set including two symbols located before the last two symbols of the subframe. In some examples of the above methods, apparatuses (equipment) or non-transitory computer-readable media, the indication is dynamically signaled via a control channel. In some examples of the above methods, apparatuses (equipment) or non-transitory computer-readable media, the CSI-RS is received on a millimeter wave (mmW) frequency resource.

[0031] A method of wireless communication is described. The method may include receiving a subframe configuration coordination message from a neighboring base station, wherein the subframe configuration coordination message includes an indication of a subframe configuration including a CSI-RS symbol set, transmitting the indication of the subframe configuration to a UE, and receiving a CSI feedback message from the UE using at least one of the CSI-RS symbol sets based at least in part on the indication of the subframe configuration.

[0032] An apparatus for wireless communication is described. The apparatus may include means for receiving a subframe configuration coordination message from a neighboring base station, wherein the subframe configuration coordination message includes an indication of a subframe configuration including a CSI-RS symbol set, means for transmitting the indication of the subframe configuration to a UE, and means for receiving a CSI feedback message from the UE using at least one of the CSI-RS symbol sets based at least in part on the indication of the subframe configuration.

[0033] Another apparatus for wireless communication is described. The apparatus may include a processor, a memory in electronic communication with the processor, and instructions stored in the memory. The instructions are operable to cause the processor to: receive a subframe configuration coordination message from a neighboring base station, wherein the subframe configuration coordination message includes an indication of a subframe configuration including a CSI-RS symbol set, transmit the indication of the subframe configuration to a UE, and receive a CSI feedback message from the UE using at least one CSI-RS symbol set in the CSI-RS symbol set based at least in part on the indication of the subframe configuration.

[0034] A non-transitory computer-readable medium for wireless communication is described. The non-transitory computer-readable medium may include instructions operable to cause a processor to perform the following operations: receiving a subframe configuration coordination message from a neighboring base station, wherein the subframe configuration coordination message includes an indication of a subframe configuration including a CSI-RS symbol set, transmitting the indication of the subframe configuration to a UE, and receiving a CSI feedback message from the UE using at least one CSI-RS symbol set in the CSI-RS symbol set based at least in part on the indication of the subframe configuration.

[0035] In some examples of the above methods, apparatuses (equipment), or non-transitory computer-readable media, the subframe configuration enables or disables one or more CSI-RS symbol sets from a plurality of CSI-RS symbol sets. In some examples of the above methods, apparatuses (equipment), or non-transitory computer-readable media, a subframe configuration coordination message is dynamically or semi-statically received via a backhaul link. Some examples of the above-described methods, apparatuses (equipment), or non-transitory computer-readable media may further include a process, feature, device, or instruction for transmitting a subframe configuration coordination message. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 An example of a system for wireless communication that supports a channel state information reference signal (CSI-RS) design with a dynamic subframe structure in accordance with aspects of the present disclosure is illustrated.

[0038] Figure 2 An example of a wireless communication system supporting CSI-RS design with a dynamic subframe structure according to aspects of the present disclosure is illustrated.

[0039] Figure 3 and 4 An example of a process flow in a system supporting CSI-RS design with a dynamic subframe structure according to aspects of the present disclosure is illustrated.

[0040] Figures 5 to 7 A block diagram illustrating an apparatus supporting CSI-RS design with a dynamic subframe structure according to aspects of the present disclosure.

[0041] Figure 8 A block diagram of a system including a UE supporting CSI-RS design with a dynamic subframe structure is illustrated in accordance with aspects of the present disclosure.

[0042] Figures 9 to 11 A block diagram illustrating an apparatus supporting CSI-RS design with a dynamic subframe structure according to aspects of the present disclosure.

[0043] Fig.12 A block diagram of a system including a base station supporting CSI-RS design with a dynamic subframe structure is illustrated in accordance with aspects of the present disclosure.

[0044] Figures 13 to 16 Methods for CSI-RS design with dynamic subframe structure according to aspects of the present disclosure are illustrated.

[0045] Detailed Description

[0046] Some wireless communication systems may operate in the millimeter wave (mmW) frequency range (e.g., 28 GHz, 40 GHz, 60 GHz, etc.). Wireless communication at these frequencies may be associated with increased signal attenuation (e.g., path loss), which may be affected by various factors (such as temperature, air pressure, diffraction, etc.). As a result, signal processing techniques (such as beamforming) may be used to coherently combine energy and overcome path loss at these frequencies. Additionally, communications in such mmW systems may be time division multiplexed, where transmissions may only be directed to one wireless device at a time due to the directionality of the transmitted signal.

[0047] Reference signals transmitted by a base station (e.g., channel state information reference signal (CSI-RS)) can be used to estimate the quality of a received signal at a user equipment (UE), which may be affected by interference from nearby wireless devices or neighboring base stations. The UE can report channel quality (e.g., channel state information (CSI)) about channel conditions to the base station based on the received reference signal.

[0048] Various subframe configurations may be used to convey data and control information. A subframe configuration may include a series of components (such as downlink (DL) data and control, uplink (UL) data and control, and CSI-RS transmission), which may be scheduled at different durations (e.g., symbol periods) over the interval of a subframe. In some cases, the accuracy of the UE's channel estimate may depend on the temporal position of the CSI-RS received in the subframe. That is, when the CSI-RS in the subframe configuration coincides with interference from DL or UL data transmission, the UE may be able to provide a more robust channel estimate.

[0049] Wireless communication systems may use a dynamic subframe structure to improve channel estimation and channel quality reporting. That is, reference signals may be positioned during different symbol periods of a subframe, where additional symbol periods may be used for CSI-RS to capture interference from other cells or wireless devices. A subframe may include two CSI-RS sets located in different symbol periods. Additionally or alternatively, the CSI-RS may be moved to a symbol period corresponding to the data portion of the subframe.

[0050] To further enhance the communication of CSI reports, the base stations may coordinate the scheduling of the various subframe configurations in use. For example, a first base station may coordinate with a second base station the subframe configuration to be used when each base station communicates. The coordination between base stations may be done via a backhaul link and may be coordinated statically or semi-statically.

[0051] Aspects of the present disclosure are initially described in the context of a wireless communication system. Aspects of the present disclosure are further explained and described with reference to apparatus diagrams, system diagrams, and flow diagrams related to CSI-RS design with a dynamic subframe structure.

[0052] Figure 1 An example of a wireless communication system 100 according to various aspects of the present disclosure is illustrated. The wireless communication system 100 includes a base station 105, a UE 115, and a core network 130. In some examples, the wireless communication system 100 may be an LTE (or Advanced LTE) network. The wireless communication system 100 may represent a system using a dynamically scheduled subframe configuration that enables enhanced channel estimation and feedback.

[0053] Base station 105 can be carried out wireless communication with UE 115 via one or more base station antennas. Each base station 105 can provide communication coverage for each corresponding geographic coverage area 110. The communication link 125 shown in wireless communication system 100 can include UL transmission from UE 115 to base station 105, or DL ​​transmission from base station 105 to UE 115. Each UE 115 can be scattered throughout the wireless communication system 100, and each UE 115 can be stationary or mobile. UE 115 can 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 similar terms. UE 115 can also be a cellular phone, a wireless modem, a handheld device, a personal computer, a tablet device, a personal electronic device, an MTC device, etc.

[0054] Each base station 105 may be in communication with the core network 130 and communicate with each other. For example, the base station 105 may be connected to the core network 130 via a backhaul link 132 (e.g., S1, etc.). The base stations 105 may communicate with each other directly or indirectly (e.g., through the core network 130) on a backhaul link 134 (e.g., X2, etc.). The base station 105 may perform radio configuration and scheduling for communication with the UE 115, or may operate under the control of a base station controller (not shown). In some examples, the base station 105 may be a macro cell, a small cell, a hotspot, etc. The base station 105 may also be referred to as an evolved B node (eNB) 105.

[0055] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, messaging, broadcast, etc. These systems may be able to support communication with multiple users by sharing available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include CDMA systems, TDMA systems, FDMA systems, and OFDMA systems. A wireless multiple-access communication system may include several base stations, each of which simultaneously supports communication for one or more communication devices, which may be further referred to as UEs.

[0056] In some cases, the wireless communication system may utilize one or more ECCs. The ECC may be characterized by one or more features, including flexible bandwidth, variable length TTI, and modified control channel configuration. In some cases, the ECC may be associated with a carrier aggregation configuration or a dual connectivity configuration (i.e., when multiple serving cells have suboptimal backhaul links). The ECC may also be configured for use in an unlicensed spectrum or a shared spectrum (where more than one operator is licensed to use the spectrum). An ECC characterized by a flexible bandwidth may include one or more segments that may be utilized by a UE 115 that is not able to monitor the entire bandwidth or prefers to use a limited bandwidth (e.g., to save power).

[0057] In some cases, ECC may utilize variable TTI lengths, which may include the use of reduced or variable symbol durations. In some cases, the symbol duration may remain the same, but each symbol may represent a different TTI. In some cases, ECC may include multiple hierarchies associated with different TTI lengths. For example, the TTIs of one hierarchy may correspond to uniform 1 ms subframes, while in a second hierarchy, variable length TTIs may correspond to bursts of short duration symbol periods. In some cases, shorter symbol durations may also be associated with increased subcarrier spacing.

[0058] Flexible bandwidth and variable TTI may be associated with modified control channel configurations (e.g., ECC may use ePDCCH for DL ​​control information). For example, one or more control channels of the ECC may utilize FDM scheduling to accommodate flexible bandwidth usage. Other control channel modifications include the use of additional control channels (e.g., for eMBMS scheduling or to indicate the length of variable length UL and DL bursts) or control channels transmitted at different intervals. The ECC may also include modified or additional HARQ-related control information.

[0059] The base station 105 may insert periodic pilot symbols (such as CRS) to assist the UE 115 in channel estimation and coherent demodulation. The CRS may include one of 504 different cell identities. It may be modulated using QPSK and power boosted (e.g., transmitted at a power 6dB higher than the sounding data element) to make them more resistant to noise and interference. The CRS may be embedded in 4 to 16 resource elements of each resource block based on the number of antenna ports or layers (up to 4) of the receiving UE 115. In addition to the CRS that can be utilized by all UEs 115 in the coverage area 110 of the base station 105, the DMRS may be directed to specific UEs 115 and may be transmitted only on resource blocks assigned to these UEs 115. The DMRS may include signals on 6 resource elements in each resource block in which the signal is transmitted. The DMRS for different antenna ports may each utilize the same 6 resource elements and may be distinguished using different orthogonal cover codes (e.g., masking each signal with different combinations of 1 or -1 in different resource elements). In some cases, two DMRS sets may be transmitted in adjacent resource elements. In some cases, an additional reference signal called a channel state information reference signal (CSI-RS) may be included to help generate CSI. On the UL, the UE 115 may transmit a combination of periodic SRS and UL DMRS for link adaptation and demodulation, respectively.

[0060] The base station 105 may collect channel condition information from the UE 115 to efficiently configure the channel. This information may be sent from the UE 115 in the form of a channel state report. The channel state report may include a request for the RI of several layers to be used for DL ​​transmission (e.g., based on the antenna port of the UE 115), a preferred PMI indicating which precoder matrix should be used (based on the number of layers), and a CQI representing the highest MCS that can be used. The CQI may be calculated by the UE 115 after receiving a predetermined pilot symbol (such as a CRS or CSI-RS). If the UE 115 does not support spatial multiplexing (or is not in a supporting spatial mode), the RI and PMI may be excluded. The type of information included in the report determines the report type. The channel state report may be periodic or aperiodic. That is, the base station 105 may configure the UE 115 to send periodic reports at regular intervals, and may also request additional reports as needed. Aperiodic reports may include wideband reports indicating channel quality across the entire cell bandwidth, UE-selected reports indicating the best subband subset, or configured reports where the reported subbands are selected by the base station 105 .

[0061] The wireless communication system 100 may operate in the millimeter wave (mmW) frequency range (e.g., 28 GHz, 40 GHz, 60 GHz, etc.). Wireless communication at these frequencies may be associated with increased signal attenuation (e.g., path loss), which may be affected by various factors (such as temperature, air pressure, diffraction, etc.). As a result, signal processing techniques (such as beamforming) may be used to coherently combine energy and overcome path loss at these frequencies. Additionally, communications in such mmW systems may be time division multiplexed, where transmissions may be directed to only one wireless device at a time due to the directionality of the transmitted signal.

[0062] Reference signals (e.g., channel state information reference signals (CSI-RS)) transmitted by base station 105 may be used to estimate the quality of a signal received by a UE, which may be affected by interference from nearby wireless devices or neighboring base stations. UE 115 may provide a report on channel quality (e.g., channel state information (CSI)) to base station 105 based on the received reference signal. Base station 105 may use the estimated channel information to schedule additional communications.

[0063] In some cases, various subframe configurations may be used to convey data and control information. A subframe configuration may include a series of components, such as DL control signals, physical downlink shared channel (PDSCH), physical uplink shared channel (PUSCH), physical uplink control channel (PUCCH), CSI-RS, sounding reference signal (SRS), beam refinement reference signal (BRRS), etc. Further signals may be included in the subframe, such as reference signals for time and / or frequency tracking purposes. These subframe components and signals may be scheduled at different times (e.g., symbol periods) over the duration of the subframe. In some cases, certain types of subframe components (such as PUCCH, SRS, or CSI-RS) may be scheduled in the symbol period at the end of the subframe.

[0064] As an example, Table 1 illustrates several different subframe configurations that may be used by the base station 105 and the UE 115 for communication. For example, subframe configuration 0 may include an initial symbol period with DL control information (Dc), followed by 11 symbol periods of DL data (Dd). The remaining symbol periods of subframe configuration 0 may further include transmissions of DL data or CSI-RS (C-RS). As shown in the table, multiple subframe configurations are possible, in which different signals may be included in different symbol periods of a subframe, such as a guard period (GP), SRS, UL control information (Uc), UL data (Ud), or BRRS (B-RS). As described above, these subframe configurations may include certain signals (such as CSI-RS) during the last symbol period of a subframe.

[0065]

[0066] Table 1

[0067] Because various subframe configurations may be used by neighboring base stations 105, the accuracy of the channel estimate for UE 115 may depend on the temporal position of the CSI-RS received during the subframe. For example, a CSI-RS transmitted by a first base station 105 may experience interference from a PUCCH, SRS, or guard period transmitted by a second base station 105. However, when the second base station 105 is transmitting DL data, the interference may not represent the interference experienced at the UE. Therefore, when the CSI-RS in the subframe configuration coincides with interference from a DL or UL data transmission (such as a PDSCH or PUSCH transmission from another base station 105), the UE 115 may be able to provide a more robust channel estimate.

[0068] Thus, the base station 105 and the UE 115 may use a subframe configuration that includes dynamically scheduled CSI-RS symbols. For example, the base station 105 may identify a subframe configuration that includes one or more CSI-RS symbol sets for a subframe. The base station may indicate to the UE 115 whether the CSI-RS symbol set may be enabled or disabled during the subframe. The UE 115 may receive multiple CSI-RS at different locations within the subframe as indicated by the base station, and the UE 115 may transmit CSI feedback to the base station 105 based on at least one of the received CSI-RS. In some examples, multiple base stations 105 may coordinate the use of subframe configurations that include CSI-RS symbols that may be enabled or disabled.

[0069] Figure 2 An example of a wireless communication system 200 for CSI-RS design with a dynamic subframe structure is illustrated. In some cases, the wireless communication system 200 may represent a system composed of a plurality of wireless communication systems such as the wireless communication system 200 and the wireless communication system 200. Figure 1 Aspects of the described techniques are performed by a UE 115 or a base station 105. A wireless communication system may support the use of subframe configurations that enable enhanced channel quality feedback and scheduling.

[0070] The CSI-RS may be transmitted in a symbol of a subframe occupied by a PDSCH or a PUSCH. The UE may receive dynamic (e.g., PDCCH or DCI) or radio resource control (RRC) signaling from the base station as to whether it should transmit one or two CSI-RS set feedbacks to the base station. The base station may notify the UE which CSI-RS symbol sets are activated or enabled. If two or more sets are activated, the base station may notify the UE which measurement sets may need to be included in the feedback sent to the base station. An indication of a CSI-RS symbol set may be dynamically signaled via a physical downlink control channel. A separate bit may be reserved in the downlink control information to convey the indication. The indication may be notified via RRC signaling. In addition, the subframe configuration message from a neighboring base station may be processed in a manner in which the neighboring base station transmits the CSI-RS in the same symbol set of the subframe. The CSI-RS may be transmitted in a symbol of a subframe occupied by a PDSCH in a neighboring base station.

[0071] Figure 3 An example of a process flow 300 in a system supporting CSI-RS design with a dynamic subframe structure is illustrated. The process flow 300 may include a base station 105-c and a UE 115-b, which may be reference Figure 1-2 Examples of corresponding devices described.

[0072] The base station 105-c may identify a subframe configuration for the subframe at step 305. The base station 105-c may also determine whether to enable or disable one or more of the plurality of CSI-RS symbol sets based at least in part on the subframe configuration.

[0073] In step 310, the base station 105-c may transmit and the UE 115-b may receive an indication that one or more of a plurality of channel state information reference signal (CSI-RS) symbol sets will be enabled or disabled. In some cases, the plurality of CSI-RS symbol sets include two non-overlapping CSI-RS symbol sets. In some examples, one of the plurality of CSI-RS symbol sets includes symbols located in the last two symbols of a subframe. The indication may indicate that a set of CSI-RS symbols located in the last two symbols of a subframe will be disabled, and a different set of CSI-RS symbols located in the data portion of the subframe will be enabled. In some examples, the indication may be dynamically signaled via a control channel. The indication to enable or disable one or more CSI-RS symbol sets may occur together with an indication of the location of the CSI-RS symbols in the subframe.

[0074] At step 315, UE 115-b may monitor one or more CSI-RS symbol sets. In some examples, the multiple CSI-RS symbol sets include a CSI-RS symbol set including two symbols located before the last two symbols of the subframe. At step 320, UE 115-b may receive one or more CSI-RS from base station 105-c at a corresponding position in the subframe according to the indication. In some cases, the CSI-RS may be received on millimeter wave (mmW) frequency resources.

[0075] In step 325, UE 115-b may transmit one or more instances of CSI feedback based at least in part on at least one of the CSI-RSs, and base station 105-c may receive one or more instances of CSI feedback based at least in part on at least one of the CSI-RSs. In some cases, the CSI feedback may include feedback based on each of the one or more sets. Additionally or alternatively, the CSI feedback may be generated based on each of the enabled CSI-RS symbol sets in the plurality of CSI-RS symbol sets.

[0076] Figure 4 An example of a process flow 400 for a system supporting CSI-RS design with a dynamic subframe structure is illustrated. The process flow 400 may include a base station 105-d, a base station 105-e, and a UE 115-c, which may be referenced Figure 1-2 Examples of corresponding devices described.

[0077] At step 405, base station 105-d may receive a subframe configuration coordination message from base station 105-e, which may be a neighboring base station. In some cases, the subframe configuration coordination message includes an indication of a subframe configuration including a set of CSI-RS symbols. The subframe configuration coordination message may be received dynamically or semi-statically via a backhaul link. In some cases, base station 105-d may transmit the subframe configuration coordination message.

[0078] At step 410, the base station 105-d may transmit an indication of a subframe configuration and the UE 115-c may receive the indication of the subframe configuration. In some cases, the subframe configuration may enable or disable one or more CSI-RS symbol sets from a plurality of CSI-RS symbol sets. At step 415, the base station 105-d may receive a CSI feedback message from the UE 115-c using at least one of the CSI-RS symbol sets based at least in part on the indication of the subframe configuration.

[0079] Figure 5 A block diagram 500 of an apparatus 505 supporting CSI-RS design with a dynamic subframe structure according to various aspects of the present disclosure is shown. The apparatus 505 may be as described with reference to Figure 1 and 2 Examples of various aspects of the UE 115 are described. The device 505 may include a receiver 510, a UE subframe configuration manager 515, and a transmitter 520. The device 505 may also include a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

[0080] The receiver 510 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 CSI-RS design with a dynamic subframe structure, etc.). The information may be passed to other components of the device. The receiver 510 may be a reference Figure 8 Examples of aspects of transceiver 840 are described.

[0081] UE subframe configuration manager 515 may be a reference Figure 8 Examples of various aspects of the UE subframe configuration manager 815 are described.

[0082] The UE subframe configuration manager 515 may receive an indication that one or more of the channel state information reference signal (CSI-RS) sets are to be enabled or disabled, and receive one or more CSI-RS at corresponding positions in the subframe according to the indication.

[0083] The transmitter 520 may transmit signals generated by other components of the device. In some examples, the transmitter 520 may be co-located with the receiver 510 in a transceiver module. For example, the transmitter 520 may be a reference Figure 8 Examples of aspects of the described transceiver 840. Transmitter 520 may include a single antenna, or it may include a group of antennas.

[0084] Figure 6 A block diagram 600 of an apparatus 605 supporting CSI-RS design with a dynamic subframe structure according to various aspects of the present disclosure is shown. The apparatus 605 may be as described with reference to Figure 1 , 2 5 and 5 illustrate examples of various aspects of the device 505 or UE 115. The device 605 may include a receiver 610, a UE subframe configuration manager 615, and a transmitter 620. The device 605 may also include a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

[0085] The receiver 610 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 CSI-RS design with a dynamic subframe structure, etc.). The information may be passed to other components of the device. The receiver 610 may be a reference Figure 8 Examples of various aspects of the transceiver 840 described herein. The UE subframe configuration manager 615 may be referenced Figure 8 Examples of various aspects of the UE subframe configuration manager 815 are described. The UE subframe configuration manager 615 may also include a subframe configuration component 625 and a CSI-RS component 630.

[0086] The subframe configuration component 625 may receive an indication that one or more of a set of channel state information reference signal (CSI-RS) symbols will be enabled or disabled. In some cases, the indication indicates that a set of CSI-RS symbols located in the last two symbols of the subframe will be disabled, and a different set of CSI-RS symbols located in the data portion of the subframe will be enabled. In some cases, the indication is dynamically signaled via a control channel. The CSI-RS component 630 may receive one or more CSI-RS at corresponding positions in the subframe according to the indication. In some cases, the CSI-RS is received on millimeter wave (mmW) frequency resources.

[0087] The transmitter 620 may transmit signals generated by other components of the device. In some examples, the transmitter 620 may be co-located with the receiver 610 in a transceiver module. For example, the transmitter 620 may be a reference Figure 8 Examples of aspects of the described transceiver 840. Transmitter 620 may include a single antenna, or it may include a group of antennas.

[0088] Figure 7 A block diagram 700 of a UE subframe configuration manager 715 supporting CSI-RS design with a dynamic subframe structure according to various aspects of the present disclosure is shown. The UE subframe configuration manager 715 may be a reference Figure 5 , 6 8 and 8. The UE subframe configuration manager 515, the UE subframe configuration manager 615, or the UE subframe configuration manager 815 are examples of various aspects. The UE subframe configuration manager 715 may include a subframe configuration component 725 and a CSI-RS component 730. Each of these modules can communicate with each other directly or indirectly (e.g., via one or more buses).

[0089] The subframe configuration component 725 can receive an indication that one or more of a set of channel state information reference signal (CSI-RS) symbols will be enabled or disabled. In some cases, the indication indicates that a set of CSI-RS symbols located in the last two symbols of the subframe will be disabled and a different set of CSI-RS symbols located in the data portion of the subframe will be enabled. In some cases, the indication is dynamically signaled via a control channel.

[0090] The CSI-RS component 730 may receive one or more CSI-RS at a corresponding position in a subframe according to the indication. In some cases, the CSI-RS is received on a millimeter wave (mmW) frequency resource. The CSI feedback component 735 may transmit one or more instances of CSI feedback based on at least one CSI-RS in the CSI-RS. In some cases, the CSI feedback includes feedback based on each of one or more sets. In some cases, the CSI feedback is generated based on each CSI-RS symbol set that has been enabled in the CSI-RS symbol set.

[0091] The CSI-RS symbol component 740 can determine which symbols in the subframe configuration include CSI-RS. In some cases, the CSI-RS symbol set includes two non-overlapping CSI-RS symbol sets. In some examples, one of the CSI-RS symbol sets includes symbols located at the last two symbols of the subframe. In some examples, the CSI-RS symbol set includes a CSI-RS symbol set including two symbols located before the last two symbols of the subframe.

[0092] Figure 8 A diagram of a system 800 including a device 805 supporting CSI-RS design with a dynamic subframe structure according to various aspects of the present disclosure is shown. The device 805 may be as described above, for example, with reference to Figure 1 , 2 , 5 and 6 describe examples of device 505, device 605, or UE 115.

[0093] The device 805 may include components for two-way voice and data communications, including components for transmitting and receiving communications, including a UE subframe configuration manager 815, a processor 825, memory 830, software 835, a transceiver 840, an antenna 845, and a beamforming operation component 850. The processor 825 may include an intelligent hardware device (e.g., a central processing unit (CPU), a microcontroller, an application specific integrated circuit (ASIC), etc.).

[0094] The memory 830 may include random access memory (RAM) and read-only memory (ROM). The memory 830 may store computer-readable, computer-executable software 835 including instructions that, when executed, cause the processor to perform the various functions described herein. In some cases, the memory 830 may include, among other things, a basic input / output system (BIOS) that may control basic hardware and / or software operations, such as interaction with peripheral components or devices.

[0095] The software 835 may include code for implementing various aspects of the present disclosure, including code for supporting CSI-RS design with a dynamic subframe structure. The software 835 may be stored in a non-transitory computer-readable medium, such as a system memory or other memory. In some cases, the software 835 may not be directly executed by a processor, but may cause a computer (e.g., when compiled and executed) to perform the functions described herein.

[0096] The transceiver 840 may communicate bidirectionally via one or more antennas, wired or wireless links, as described above. For example, the transceiver 840 may represent a wireless transceiver and may communicate bidirectionally with another wireless transceiver. The transceiver 840 may also include a modem to modulate packets and provide the modulated packets to an antenna for transmission, and demodulate packets received from the antenna. In some cases, the wireless device may include a single antenna 845. However, in some cases, the device may have more than one antenna 845, which may be capable of transmitting or receiving multiple wireless transmissions concurrently. The beamforming operation component 850 may enable the beamforming operations described herein.

[0097] Fig. 9 A block diagram 900 of a device 905 supporting CSI-RS design with a dynamic subframe structure according to various aspects of the present disclosure is shown. The device 905 may be as described with reference to Figure 1 and 2 Examples of various aspects of the base station 105 are described. The device 905 may include a receiver 910, a base station subframe configuration manager 915, and a transmitter 920. The device 905 may also include a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

[0098] The receiver 910 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 CSI-RS design with a dynamic subframe structure, etc.). The information may be passed to other components of the device. The receiver 910 may be a reference Fig.12 Examples of aspects of transceiver 1240 are described.

[0099] The base station subframe configuration manager 915 may be a reference Fig.12 Examples of various aspects of the base station subframe configuration manager 1215 are described.

[0100] The base station subframe configuration manager 915 may transmit an indication that one or more of the channel state information reference signal (CSI-RS) symbol sets will be enabled or disabled, transmit one or more CSI-RSs at corresponding positions in the subframe according to the indication, receive a subframe configuration coordination message from a neighboring base station, wherein the subframe configuration coordination message includes an indication of a subframe configuration including a channel state information reference signal (CSI-RS) symbol set, transmit the indication of the subframe configuration to the UE, and use at least one of the CSI-RS symbol sets in the CSI-RS symbol set to receive a CSI feedback message from the UE based on the indication of the subframe configuration.

[0101] The transmitter 920 may transmit signals generated by other components of the device. In some examples, the transmitter 920 may be co-located with the receiver 910 in a transceiver module. For example, the transmitter 920 may be a reference Fig.12 Examples of aspects of the described transceiver 1240. Transmitter 920 may include a single antenna, or it may include a group of antennas.

[0102] Fig.10 A block diagram 1000 of a device 1005 supporting CSI-RS design with a dynamic subframe structure according to various aspects of the present disclosure is shown. The device 1005 may be as described with reference to Figure 1 , 2 9 and 9 are examples of various aspects of the device 905 or base station 105. The device 1005 may include a receiver 1010, a base station subframe configuration manager 1015, and a transmitter 1020. The device 1005 may also include a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

[0103] The receiver 1010 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 CSI-RS design with a dynamic subframe structure, etc.). The information may be passed to other components of the device. The receiver 1010 may be a reference Fig.12 Examples of aspects of transceiver 1240 are described.

[0104] The base station subframe configuration manager 1015 may be a reference Fig.12 Examples of various aspects of the base station subframe configuration manager 1215 are described. The base station subframe configuration manager 1015 may also include a subframe configuration component 1025, a CSI-RS component 1030, a subframe coordination component 1035, and a CSI feedback component 1040.

[0105] The subframe configuration component 1025 may transmit an indication that one or more of a set of channel state information reference signal (CSI-RS) symbols will be enabled or disabled, and an indication of the subframe configuration to the UE. In some cases, the indication indicates that a set of CSI-RS symbols located in the last two symbols of the subframe will be disabled, and a different set of CSI-RS symbols located in the data portion of the subframe will be enabled. In some cases, the indication is dynamically signaled via a control channel. In some cases, the subframe configuration enables or disables one or more sets of CSI-RS symbols from the set of CSI-RS symbols.

[0106] The CSI-RS component 1030 may transmit one or more CSI-RS at corresponding positions in the subframe according to the indication. In some cases, the CSI-RS is received on millimeter wave (mmW) frequency resources.

[0107] The subframe coordination component 1035 may receive a subframe configuration coordination message from a neighboring base station, wherein the subframe configuration coordination message includes an indication of a subframe configuration including a set of channel state information reference signal (CSI-RS) symbols, and transmit the subframe configuration coordination message. In some cases, the subframe configuration coordination message is received dynamically or semi-statically via a backhaul link.

[0108] The CSI feedback component 1040 may receive one or more instances of CSI feedback based on the indication, and receive a CSI feedback message from the UE using at least one CSI-RS symbol set in the CSI-RS symbol set based on the indication of the subframe configuration. In some cases, the CSI feedback includes feedback based on each of the one or more sets. In some cases, the CSI feedback is generated based on all enabled CSI-RS symbol sets in the CSI-RS symbol set.

[0109] Transmitter 1020 may transmit signals generated by other components of the device. In some examples, transmitter 1020 may be co-located with receiver 1010 in a transceiver module. For example, transmitter 1020 may be a reference Fig.12 Examples of aspects of the described transceiver 1240. The transmitter 1020 may include a single antenna, or it may include a group of antennas.

[0110] Fig.11 A block diagram 1100 of a base station subframe configuration manager 1115 supporting CSI-RS design with a dynamic subframe structure according to various aspects of the present disclosure is shown. The base station subframe configuration manager 1115 may be a reference Fig. 9 , 10 12 and 13. The base station subframe configuration manager 1115 may include a subframe configuration component 1125, a CSI-RS component 1130, a subframe coordination component 1135, and a CSI feedback component 1140. Each of these modules may communicate with each other directly or indirectly (e.g., via one or more buses).

[0111] The subframe configuration component 1125 may transmit an indication that one or more of a set of channel state information reference signal (CSI-RS) symbols will be enabled or disabled, and an indication of the subframe configuration to the UE. In some cases, the indication indicates that a set of CSI-RS symbols located in the last two symbols of the subframe will be disabled, and a different set of CSI-RS symbols located in the data portion of the subframe will be enabled. In some cases, the indication is dynamically signaled via a control channel. In some cases, the subframe configuration enables or disables one or more sets of CSI-RS symbols from the set of CSI-RS symbols.

[0112] The CSI-RS component 1130 may transmit one or more CSI-RS at corresponding positions in the subframe according to the indication. In some cases, the CSI-RS is received on a millimeter wave (mmW) frequency resource. The subframe coordination component 1135 may receive a subframe configuration coordination message from a neighboring base station, wherein the subframe configuration coordination message includes an indication of a subframe configuration including a set of channel state information reference signal (CSI-RS) symbols, and transmits the subframe configuration coordination message. In some cases, the subframe configuration coordination message is received dynamically or semi-statically via a backhaul link.

[0113] The CSI feedback component 1140 may receive one or more instances of CSI feedback based on the indication, and receive a CSI feedback message from the UE using at least one CSI-RS symbol set in the CSI-RS symbol set based on the indication of the subframe configuration. In some cases, the CSI feedback includes feedback based on each of the one or more sets. In some cases, the CSI feedback is generated based on all enabled CSI-RS symbol sets in the CSI-RS symbol set.

[0114] The CSI-RS symbol component 1145 may provide an indication of how many CSI-RS symbol sets will be transmitted and where in the subframe the CSI-RS symbols will be transmitted. In some cases, the CSI-RS symbol set includes two CSI-RS symbol sets. In some cases, one of the CSI-RS symbol sets includes a CSI-RS symbol set located at the last two symbols of the subframe. In some examples, the CSI-RS symbol set includes a CSI-RS symbol set including two symbols located before the last two symbols of the subframe. The indication that one or more CSI-RS symbol sets will be enabled or disabled may occur together with an indication of the location of the CSI-RS symbols in the subframe.

[0115] Fig.12 A diagram of a system 1200 including a device 1205 supporting CSI-RS design with a dynamic subframe structure according to various aspects of the present disclosure is shown. The device 1205 may be as described above, for example, with reference to Figure 1 , 2 , 9 and 10 describe examples of device 905, device 1005, or base station 105.

[0116] Device 1205 may include components for two-way voice and data communications, including components for transmitting and receiving communications, including a base station subframe configuration manager 1215, a processor 1225, memory 1230, software 1235, a transceiver 1240, an antenna 1245, a network communication manager 1250, and a base station communication manager 1255. Processor 1225 may include an intelligent hardware device (e.g., a central processing unit (CPU), a microcontroller, an application specific integrated circuit (ASIC), etc.).

[0117] Memory 1230 may include random access memory (RAM) and read-only memory (ROM). Memory 1230 may store computer-readable, computer-executable software 1235 including instructions that, when executed, cause the processor to perform the various functions described herein. In some cases, memory 1230 may include, among other things, a basic input / output system (BIOS), which may control basic hardware and / or software operations, such as interaction with peripheral components or devices.

[0118] The software 1235 may include code for implementing various aspects of the present disclosure, including code for supporting CSI-RS design with a dynamic subframe structure. The software 1235 may be stored in a non-transitory computer-readable medium, such as a system memory or other memory. In some cases, the software 1235 may not be directly executed by a processor, but may cause a computer (e.g., when compiled and executed) to perform the functions described herein.

[0119] The transceiver 1240 may communicate bidirectionally via one or more antennas, wired or wireless links, as described above. For example, the transceiver 1240 may represent a wireless transceiver and may communicate bidirectionally with another wireless transceiver. The transceiver 1240 may also include a modem to modulate packets and provide the modulated packets to an antenna for transmission, and demodulate packets received from an antenna.

[0120] In some cases, the wireless device may include a single antenna 1245. However, in some cases, the device may have more than one antenna 1245, which may be capable of transmitting or receiving multiple wireless transmissions concurrently. The network communication manager 1250 may manage communications with the core network (e.g., via one or more wired backhaul links). For example, the network communication manager 1250 may manage the delivery of data communications for client devices (such as one or more UEs 115).

[0121] Base station communication manager 1255 may manage communications with other base stations 105 and may include a controller or scheduler for controlling communications with UE 115 in coordination with other base stations 105. For example, base station communication manager 1255 may coordinate scheduling of transmissions to UE 115 for various interference mitigation techniques, such as beamforming or joint transmissions. In some examples, base station communication manager 1255 may provide an X2 interface within an LTE / LTE-A wireless communication network technology to provide communications between base stations 105.

[0122] Fig.13 A flow chart illustrating a method 1300 for CSI-RS design with a dynamic subframe structure according to aspects of the present disclosure is shown. The operations of the method 1300 may be implemented by a UE 115 or components thereof as described herein. For example, the operations of the method 1300 may be implemented by reference to Figures 5 to 7 In some examples, the UE 115 may execute a set of codes for controlling the functional elements of the device to perform the functions described below. Additionally or alternatively, the UE 115 may use dedicated hardware to perform various aspects of the functions described below.

[0123] At block 1305, UE 115 may receive an indication that one or more of a plurality of channel state information reference signal (CSI-RS) symbol sets are to be enabled or disabled. The operation of block 1305 may be based on the reference signal. Figures 2 to 4 In some examples, various aspects of the operation of block 1305 may be performed as described with reference to Figures 5 to 7 The described subframe configuration component is performed.

[0124] At block 1310, UE 115 may receive one or more CSI-RS at corresponding positions in a subframe according to the indication. The operation of block 1310 may be based on reference Figures 2 to 4 In some examples, various aspects of the operation of block 1310 may be performed as described with reference to Figures 5 to 7 The described CSI-RS components are performed.

[0125] Fig.14 1 is a flow chart illustrating a method 1400 for CSI-RS design with dynamic subframe structure according to aspects of the present disclosure. The operations of the method 1400 may be implemented by the UE 115 or components thereof as described herein. For example, the operations of the method 1400 may be implemented by referring to Figures 5 to 7 In some examples, the UE 115 may execute a set of codes for controlling the functional elements of the device to perform the functions described below. Additionally or alternatively, the UE 115 may use dedicated hardware to perform various aspects of the functions described below.

[0126] At block 1405, UE 115 may receive an indication that one or more of a plurality of channel state information reference signal (CSI-RS) symbol sets are to be enabled or disabled. The operation of block 1405 may be based on the reference signal. Figures 2 to 4 In some examples, various aspects of the operation of block 1405 may be performed as described with reference to Figures 5 to 7 The described subframe configuration component is performed.

[0127] At block 1410, UE 115 may receive one or more CSI-RS at corresponding positions in a subframe according to the indication. The operation of block 1410 may be based on reference Figures 2 to 4 In some examples, various aspects of the operation of block 1410 may be performed as described with reference to Figures 5 to 7 The described CSI-RS components are performed.

[0128] At block 1415, UE 115 may transmit one or more instances of CSI feedback based on at least one of the CSI-RSs. The operations of block 1415 may be based on reference Figures 2 to 4 In some examples, various aspects of the operation of block 1415 may be performed as described with reference to Figures 5 to 7 The CSI-RS feedback component described above is performed.

[0129] Fig.15 A flow chart illustrating a method 1500 for CSI-RS design with a dynamic subframe structure according to aspects of the present disclosure is shown. The operations of the method 1500 may be implemented by a base station 105 or components thereof as described herein. For example, the operations of the method 1500 may be implemented by reference to Figures 9 to 11 In some examples, the base station 105 may execute a set of codes for controlling the functional elements of the device to perform the functions described below. Additionally or alternatively, the base station 105 may use dedicated hardware to perform various aspects of the functions described below.

[0130] At block 1505, the base station 105 may transmit an indication that one or more of a plurality of channel state information reference signal (CSI-RS) symbol sets will be enabled or disabled. The operation of block 1505 may be based on the reference signal. Figures 2 to 4 In some examples, aspects of the operations of block 1505 may be performed as described with reference to Figures 9 to 11 The described subframe configuration component is performed.

[0131] At block 1510, the base station 105 may transmit one or more CSI-RS at corresponding positions in the subframe according to the indication. The operation of block 1510 may be based on reference Figures 2 to 4 In some examples, aspects of the operations of block 1510 may be performed as described with reference to Figures 9 to 11 The described CSI-RS components are performed.

[0132] Fig.16 A flow chart illustrating a method 1600 for CSI-RS design with a dynamic subframe structure according to various aspects of the present disclosure is shown. The operations of the method 1600 may be implemented by the base station 105 or components thereof as described herein. For example, the operations of the method 1600 may be implemented by reference to Figures 9 to 11 In some examples, the base station 105 may execute a set of codes for controlling the functional elements of the device to perform the functions described below. Additionally or alternatively, the base station 105 may use dedicated hardware to perform various aspects of the functions described below.

[0133] At block 1605, the base station 105 may receive a subframe configuration coordination message from a neighboring base station, wherein the subframe configuration coordination message includes an indication of a subframe configuration including a set of channel state information reference signal (CSI-RS) symbols. The operation of block 1605 may be based on reference Figures 2 to 4 In some examples, various aspects of the operation of block 1605 may be performed as described with reference to Figures 9 to 11 The described subframe coordination component is performed.

[0134] At block 1610, the base station 105 may transmit an indication of the subframe configuration to the UE. The operation of block 1610 may be performed according to the reference Figures 2 to 4 In some examples, various aspects of the operation of block 1610 may be performed as described with reference to Figures 9 to 11 The described subframe configuration component is performed.

[0135] In some examples, at block 1615, the base station 105 may optionally use at least one of the CSI-RS symbol sets to receive a CSI feedback message from the UE based on the indication of the subframe configuration. The operation of block 1615 may be based on reference Figures 2 to 4 In some examples, various aspects of the operation of block 1615 may be performed as described with reference to Figures 9 to 11 The CSI-RS feedback component described above is performed.

[0136] It should be noted that the above methods describe possible implementations, and that the operations and steps may be rearranged or otherwise modified and other implementations are possible. Furthermore, aspects from two or more methods may be combined.

[0137] The technology described herein can be used for various wireless communication systems, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA) and other systems. The terms "system" and "network" are often used interchangeably. Code division multiple access (CDMA) systems can implement radio technologies such as CDMA2000, Universal Terrestrial Radio Access (UTRA). CDMA2000 covers IS-2000, IS-95 and IS-856 standards. IS-2000 versions are often referred to as CDMA2000 1X, 1X, etc. IS-856 (TIA-856) is often referred to as CDMA2000 1xEV-DO, high rate packet data (HRPD), etc. UTRA includes wideband CDMA (WCDMA) and other CDMA variants. Time division multiple access (TDMA) systems can implement radio technologies such as global system for mobile communications (GSM).

[0138] Orthogonal frequency division multiple access (OFDMA) systems can implement radio technologies such as ultra mobile broadband (UMB), evolved UTRA (E-UTRA), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE802.20, Flash-OFDM, etc. UTRA and E-UTRA are part of Universal Mobile Telecommunications System (UMTS). 3GPP Long Term Evolution (LTE) and Advanced LTE (LTE-A) are new Universal Mobile Telecommunications System (UMTS) versions using E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, and Global System for Mobile Communications (GSM) are described in documents from an organization named "3rd Generation Partnership Project" (3GPP). CDMA2000 and UMB are described in documents from an organization named "3rd Generation Partnership Project 2" (3GPP2). The technology described herein can be used for the above-mentioned systems and radio technologies as well as other systems and radio technologies. Although aspects of an LTE system may be described for example purposes, and LTE terminology is used in much of the description above, the techniques described herein may also be applicable to applications other than LTE applications.

[0139] In LTE / LTE-A networks (including such networks described herein), the term evolved Node B (eNB) may be generally used to describe a base station. One or more wireless communication systems described herein may include heterogeneous LTE / LTE-A networks in which different types of evolved Node Bs (eNBs) provide coverage for various geographic regions. For example, each eNB or base station may provide communication coverage for a macro cell, a small cell, or other types of cells. Depending on the context, the term "cell" is a 3GPP term that may be used to describe a base station, a carrier or component carrier associated with a base station, or a coverage area (e.g., a sector, etc.) of a carrier or base station.

[0140] A base station 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, a radio transceiver, a Node B, an evolved Node B (eNB), a Home Node B, a Home Evolved Node B, or some other suitable term. The geographic coverage area of ​​a base station may be divided into sectors that constitute only a portion of the coverage area. One or more wireless communication systems described herein may include different types of base stations (e.g., macro or small cell base stations). The UE 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, etc.). There may be overlapping geographic coverage areas of different technologies.

[0141] A macro cell generally covers a relatively large geographic area (e.g., an area with a radius of several kilometers) and may allow unrestricted access by UEs with service subscriptions to a network provider. Compared to a macro cell, a small cell is a low-power base station that may operate in the same or different (e.g., licensed, unlicensed, etc.) frequency band as a macro cell. According to various examples, a small cell may include a pico cell, a femto cell, and a micro cell. A pico cell, for example, may cover a smaller geographic area and may allow unrestricted access by UEs with service subscriptions to a network provider. A femto cell may also cover a smaller geographic area (e.g., a residence) and may provide restricted access by UEs associated with the femto cell (e.g., UEs in a closed subscriber group (CSG), UEs of users in the residence, etc.). An eNB for a macro cell may be referred to as a macro eNB. An eNB for a small cell may be referred to as a small cell eNB, a pico eNB, a femto eNB, or a home eNB. An eNB may support one or more (e.g., two, three, four, etc.) cells (e.g., component carriers). 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, etc.

[0142] One or more wireless communication systems described herein may support synchronous or asynchronous operation. For synchronous operation, each base station may have similar frame timing, and transmissions from different base stations may be approximately aligned in time. For asynchronous operation, each base station may have different frame timing, and transmissions from different base stations may not be aligned in time. The techniques described herein may be used for synchronous or asynchronous operation.

[0143] Downlink transmissions described herein may also be referred to as forward link transmissions, and uplink transmissions may also be referred to as reverse link transmissions. Each communication link described herein, such as including Figure 1 and 2 The wireless communication systems 100 and 200 may include one or more carriers, where each carrier may be a signal composed of multiple subcarriers (eg, waveform signals of different frequencies).

[0144] The descriptions set forth herein in conjunction with the accompanying drawings describe example configurations and do not represent all examples that may be implemented or that fall within the scope of the claims. The term "exemplary" as used herein means "used as an example, instance, or illustration" and does not mean "better than" or "better than other examples." This detailed description includes specific details to provide an understanding of the described techniques. However, these techniques may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form to avoid obscuring the concepts of the described examples.

[0145] In the accompanying drawings, similar components or features may have the same reference number. In addition, various components of the same type may be distinguished by following the reference number with a dash and a second reference number that distinguishes between the similar components. If only the first reference number is used in the specification, the description may apply to any of the similar components having the same first reference number regardless of the second reference number.

[0146] The information and signals described herein may be represented using any of a variety of different techniques and technologies. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be mentioned throughout the above description may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or optical particles, or any combination thereof.

[0147] The various illustrative blocks and modules described in conjunction with the disclosure herein may be implemented or executed with a general purpose processor, DSP, ASIC, 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. A general purpose processor may be a microprocessor, but in an alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices (e.g., a combination of a digital signal processor (DSP) and a microprocessor, a plurality of microprocessors, one or more microprocessors in cooperation with a DSP core, or any other such configuration).

[0148] The functions described herein can be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, each function can be stored on a computer-readable medium as one or more instructions or codes or transmitted by it. Other examples and implementations fall within the scope of the present disclosure and the appended claims. For example, due to the nature of software, the above functions can be implemented using software, hardware, firmware, hard wiring, or any combination thereof executed by a processor. The features that implement the functions can also be physically located in various locations, including being distributed so that the various parts of the functions are implemented at different physical locations. In addition, as used herein (including in the claims), the "or" used in the enumeration of items (e.g., enumeration of items with words such as "at least one of" or "one or more of") indicates an inclusive enumeration, so that, for example, the enumeration 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).

[0149] Computer readable medium includes both non-transient computer storage medium and communication medium, and it includes any medium that facilitates computer program to transfer from one place to another place.Non-transient storage medium can be any available medium that can be accessed by general or special-purpose computer.As an example and not limitation, non-transient computer readable medium can include RAM, ROM, electrically erasable programmable read-only memory (EEPROM), compact disk (CD) ROM or other optical disk storage, disk storage or other magnetic storage device, or can be used to carry or store instruction or data structure form of desired program code means and can be accessed by general or special-purpose computer or general or special-purpose processor any other non-transient medium.Any connection is also properly referred to as computer readable medium.For example, if software is transmitted from website, server or other remote source using coaxial cable, optical fiber cable, twisted pair, digital subscriber line (DSL) or wireless technology such as infrared, radio and microwave, then the coaxial cable, optical fiber cable, twisted pair, digital subscriber line (DSL) or wireless technology such as infrared, radio and microwave are just included in the definition of medium. Disk and disc as used herein include CDs, laser discs, optical discs, digital versatile discs (DVDs), floppy disks, and Blu-ray discs, where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media.

[0150] The description herein is provided to enable those skilled in the art to make or use the present disclosure. Various modifications to the present disclosure will be apparent to those skilled in the art, and the universal principles defined herein may be applied to other variations without departing from the scope of the present disclosure. Thus, the present disclosure is not limited to the examples and designs described herein, but should be granted the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for wireless communication, comprising: receiving an indication of a subframe configuration; disabling at least one channel state information reference signal (CSI-RS) resource set from a plurality of channel state information reference signal (CSI-RS) resource sets based at least in part on the subframe configuration, the subframe configuration defining symbols associated with the at least one CSI-RS resource set as uplink symbols; as well as One or more CSI-RSs are received at corresponding positions in the subframe according to the indication. 2 . The method of claim 1 , wherein the one or more CSI-RSs are received in symbols occupied by a physical downlink shared channel (PDSCH) or a physical uplink shared channel (PUSCH) in the subframe.

3. The method of claim 1 , wherein receiving one or more CSI-RSs comprises receiving a plurality of CSI-RSs at corresponding positions in a subframe according to an indication, the method further comprising: One or more instances of CSI feedback are transmitted based at least in part on the received plurality of CSI-RS.

4. The method of claim 3, wherein transmitting one or more instances of CSI feedback comprises transmitting an instance of CSI feedback corresponding to a first CSI-RS in the plurality of CSI-RSs, the method further comprising: Transmitting CSI feedback corresponding to a second CSI-RS among the plurality of CSI-RSs is refrained, the second CSI-RS being associated with disabling the at least one CSI-RS resource set.

5. The method of claim 3, wherein transmitting one or more instances of CSI feedback comprises transmitting an instance of CSI feedback corresponding to each CSI-RS of the plurality of CSI-RSs.

6. The method of claim 3, further comprising: Dynamic or Radio Resource Control, RRC, signaling is received by the user equipment, UE, from a base station indicating whether one or more instances of CSI-RS feedback are to be transmitted to the base station.

7. The method of claim 1, wherein the plurality of CSI-RS resource sets include resources mapped to two non-overlapping CSI-RS symbol sets.

8. The method of claim 1, wherein the indication indicates that a first set of CSI-RS symbols in the one or more sets of CSI-RS resources will be enabled, and a second set of CSI-RS symbols in the one or more sets of CSI-RS resources will be enabled.

9. The method of claim 8, wherein the first set of CSI-RS symbols corresponds to a time position of a data portion of the subframe.

10. The method of claim 1, wherein the indication is dynamically signaled via a control channel or via Radio Resource Control (RRC) signaling.

11. The method of claim 10, further comprising: One or more bits are transmitted in downlink control information to convey the indication.

12. The method of claim 1, wherein the one or more CSI-RS are received on millimeter wave (mmW) frequency resources.

13. A method for wireless communication, comprising: transmitting an indication of a subframe configuration, the indication indicating that at least one set of channel state information reference signal (CSI-RS) resources from a plurality of sets of CSI-RS resources is to be disabled, the subframe configuration defining a symbol associated with the at least one set of CSI-RS resources as an uplink symbol; as well as One or more CSI-RS are transmitted at corresponding positions in the subframe according to the indication.

14. The method of claim 13, wherein transmitting one or more CSI-RSs comprises transmitting a plurality of CSI-RSs at corresponding positions in a subframe according to the indication, the method further comprising: One or more instances of CSI feedback are received based at least in part on the transmitted plurality of CSI-RS.

15. The method of claim 14, wherein receiving one or more instances of CSI feedback comprises receiving an instance of CSI feedback corresponding to a first CSI-RS of the plurality of CSI-RSs and a lack of CSI feedback corresponding to a second CSI-RS of the plurality of CSI-RSs based at least in part on the indication.

16. The method of claim 14, wherein receiving one or more instances of CSI feedback comprises receiving an instance of CSI feedback corresponding to each of the plurality of CSI-RSs based at least in part on the indication.

17. The method of claim 14, further comprising: Dynamic or Radio Resource Control (RRC) signaling is transmitted by a base station to a user equipment (UE) indicating whether one or more instances of CSI-RS feedback are to be transmitted by the UE.

18. An apparatus for wireless communication, comprising: A processor of a user equipment UE; a transceiver coupled to the processor; as well as a memory coupled to the processor, the memory and the processor being configured to cause the apparatus to: receiving an indication of a subframe configuration; disabling at least one channel state information reference signal (CSI-RS) resource set from a plurality of channel state information reference signal (CSI-RS) resource sets based at least in part on the subframe configuration, the subframe configuration defining symbols associated with the at least one CSI-RS resource set as uplink symbols; as well as One or more CSI-RSs are received at corresponding positions in the subframe according to the indication.

19. The apparatus of claim 18, wherein the memory and the processor configured to receive one or more CSI-RS are further configured to cause the apparatus to: The one or more CSI-RS are received in symbols occupied by a physical downlink shared channel (PDSCH) or a physical uplink shared channel (PUSCH) in the subframe.

20. The apparatus of claim 18, wherein the memory and the processor configured to receive one or more CSI-RS are further configured to cause the apparatus to: receiving a plurality of CSI-RS at corresponding positions in a subframe according to the indication, the memory and the processor being further configured to cause the apparatus to: One or more instances of CSI feedback are transmitted based at least in part on the received plurality of CSI-RS.

21. The apparatus of claim 20, wherein the memory and the processor configured to transmit one or more instances of CSI feedback are further configured to cause the apparatus to: transmitting an instance of CSI feedback corresponding to a first CSI-RS of the plurality of CSI-RSs, the memory and the processor being further configured to cause the apparatus to: Transmitting CSI feedback corresponding to a second CSI-RS among the plurality of CSI-RSs is refrained, the second CSI-RS being associated with disabling the at least one CSI-RS resource set.

22. The apparatus of claim 20, wherein the memory and the processor configured to transmit one or more instances of CSI feedback are further configured to cause the apparatus to: An instance of CSI feedback corresponding to each of the plurality of CSI-RSs is transmitted.

23. The apparatus of claim 20, wherein the memory and the processor are further configured to cause the apparatus to: Dynamic or radio resource control (RRC) signaling is received by the UE from a base station indicating whether one or more instances of CSI-RS feedback are to be transmitted to the base station.

24. The apparatus of claim 18, the plurality of CSI-RS resource sets comprising resources mapped to two non-overlapping CSI-RS symbol sets.

25. The apparatus of claim 18, wherein the indication indicates that a first set of CSI-RS symbols in the one or more sets of CSI-RS resources is to be enabled and a second set of CSI-RS symbols in the one or more sets of CSI-RS resources is to be enabled.

26. The apparatus of claim 25, wherein the first set of CSI-RS symbols corresponds to a time position of a data portion of the subframe.

27. An apparatus for wireless communication, comprising: A processor of the base station; a transceiver coupled to the processor; as well as a memory coupled to the processor, the memory and the processor being configured to cause the apparatus to: transmitting an indication of a subframe configuration, the indication indicating that at least one set of channel state information reference signal (CSI-RS) resources from a plurality of sets of CSI-RS resources is to be disabled, the subframe configuration defining a symbol associated with the at least one set of CSI-RS resources as an uplink symbol; as well as One or more CSI-RS are transmitted at corresponding positions in the subframe according to the indication.

28. The apparatus of claim 27, wherein the memory and the processor configured to transmit one or more CSI-RS are further configured to cause the apparatus to: transmitting a plurality of CSI-RS at corresponding positions in a subframe according to the indication, the memory and the processor are further configured to cause the apparatus to: One or more instances of CSI feedback are received based at least in part on the transmitted plurality of CSI-RS.

29. The apparatus of claim 27, wherein the memory and the processor configured to receive one or more instances of CSI feedback are further configured to cause the apparatus to: An instance of CSI feedback corresponding to a first CSI-RS of the plurality of CSI-RSs and an absence of CSI feedback corresponding to a second CSI-RS of the plurality of CSI-RSs is received based at least in part on the indication.

30. The apparatus of claim 27, wherein the memory and the processor configured to receive one or more instances of CSI feedback are further configured to cause the apparatus to: An instance of CSI feedback corresponding to each of the plurality of CSI-RSs is received based at least in part on the indication.

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