Signaling for configuration of downlink coordinated multipoint communications

Abstract

Embodiments of the present disclosure describe devices, methods, computer-readable media, and systems configurations for configuration of downlink coordinated multipoint (CoMP) communications in a wireless communication network. A user equipment (UE) may receive, from an evolved Node B (eNB), a radio resource control (RRC) transmission including channel state informations (CSI) reference signal (RS) parameters for a plurality of transmission points. The UE may subsequently receive a medium access control (MAC) control element (CE) including a plurality of index bits corresponding to one or more activated transmission points of the plurality of transmission points for which the feedback module is to generate CSI-RS feedback. The eNB may dynamically update the transmission points that are activated for CSI-RS feedback. The UE may receive another MAC CE from the eNB to notify the UE of the updated set of activated transmission points.

1 - 53 . (canceled) 
     
     
         54 . An apparatus to be employed by a user equipment (UE), the apparatus comprising:
 a communications module configured to communicate with an evolved NodeB (eNB) over a wireless communications network;   a feedback module coupled to the communications module and configured to:
 receive a radio resource control (RRC) transmission including channel state information (CSI) reference signal (RS) parameters for a plurality of transmission points; and 
 receive a medium access control (MAC) control element (CE) including a plurality of index bits corresponding to one or more activated transmission points of the plurality of transmission points for which the feedback module is to generate CSI-RS feedback. 
   
     
     
         55 . The apparatus of  claim 54 , wherein the feedback module is further configured to:
 generate CSI-RS feedback for the activated transmission points based on the CSI-RS parameters; and   transmit the CSI-RS feedback for one or more of the activated transmission points to the eNB.   
     
     
         56 . The apparatus of  claim 55 , wherein the RRC transmission further includes a maximum number, and wherein the feedback module is further configured to:
 select a number of the activated transmission points based on quality of respective transmissions, wherein the number is less than or equal to the maximum number; and   transmit the CSI-RS feedback for the selected transmission points.   
     
     
         57 . The apparatus of  claim 54 , wherein the CSI-RS parameters include a CSI-RS bandwidth parameter for the individual transmission points. 
     
     
         58 . The apparatus of  claim 54 , wherein the RRC transmission further includes cell-specific frame structure parameters for one or more cells to which the individual transmission points belong. 
     
     
         59 . The apparatus of  claim 54 , wherein the MAC CE includes:
 a MAC protocol data unit (PDU) subheader with a logical channel identifier (LCID) to identify the MAC CE as related to activation or deactivation of CSI feedback for CoMP configuration; and   a body including the plurality of index bits.   
     
     
         60 . The apparatus of  claim 54 , wherein individual index bits correspond to individual CSI-RS resources of the transmission points to indicate if the CSI-RS resources are active for CSI feedback. 
     
     
         61 . The apparatus of  claim 54 , wherein the index bits point to a bitmap of a pre-defined table including a plurality of bitmaps, the bitmap indicating the activated transmission points. 
     
     
         62 . The apparatus of  claim 54 , wherein the MAC CE further includes one or more CoMP-mode bits indicating a CoMP mode to be used by the UE. 
     
     
         63 . The apparatus of  claim 62 , wherein the MAC CE includes six index bits and one CoMP-mode bit. 
     
     
         64 . The apparatus of  claim 62 , wherein the MAC CE includes twelve index bits, two CoMP-mode bits, one bit to indicate if the MAC CE corresponds to a downlink configuration or an uplink configuration, and one bit to enable an autonomous selection of a subset of activated CSI-RS resources for reporting by the UE. 
     
     
         65 . An apparatus for managing coordinated multipoint (CoMP) communications with a user equipment on a wireless communications network, the apparatus comprising:
 a communications module configured to communicate with the UE over the wireless communications network;   a CoMP management module coupled to the communications module and configured to:
 transmit CoMP configuration parameters to the UE, the CoMP configuration parameters including channel state information (CSI) reference signal (RS) parameters for individual transmission points of a candidate measurement set including a plurality of transmission points, the CSI-RS parameters including a CSI-RS bandwidth parameter; and 
 transmit a transmission to the UE to identify individual transmission points of the candidate measurement set for which the UE is to generate CSI-RS feedback based on the CSI-RS bandwidth parameter. 
   
     
     
         66 . The apparatus of  claim 65 , wherein the transmission identifying the individual transmission points for which the UE is to generate CSI feedback includes a medium access control (MAC) control element (CE) having a plurality of index bits corresponding to one or more activated transmission points of the candidate measurement set for which the UE is to generate the CSI-RS feedback. 
     
     
         67 . The apparatus of  claim 66 , wherein individual index bits correspond to individual transmission points of the candidate measurement set to indicate if a CSI-RS resource of the individual transmission point is active for CSI feedback. 
     
     
         68 . The apparatus of  claim 66 , wherein the index bits point to a bitmap of a pre-defined table including a plurality of bitmaps. 
     
     
         69 . The apparatus of  claim 66 , wherein the MAC CE further includes a CoMP-mode bit having a first value if a CoMP mode to be used by the UE is joint transmission. 
     
     
         70 . The apparatus of  claim 66 , wherein the MAC CE further includes a pair of CoMP-mode bits to indicate if a CoMP mode to be used by the UE is joint transmission, dynamic point selection, or coordinated scheduling/coordinated beamforming. 
     
     
         71 . The apparatus of  claim 66 , wherein the MAC CE includes a first bit to indicate if the MAC CE corresponds to a downlink configuration or an uplink configuration. 
     
     
         72 . One or more non-transitory computer-readable media having instructions, stored thereon, that, when executed cause a user equipment (UE) to:
 receive, via radio resource control (RRC) signaling, channel state information (CSI) reference signal (RS) parameters for a plurality of transmission points; and   receive a medium access control (MAC) control element (CE) to identify one or more activated transmission points, of the plurality of transmission points, for which the UE is to generate CSI-RS feedback.   
     
     
         73 . The one or more computer-readable media of  claim 72 , wherein the instructions, when executed, further cause the UE to:
 generate CSI-RS feedback for the activated transmission points based on the received CSI-RS parameters; and   transmit the CSI-RS feedback for one or more of the activated transmission points to the eNB.   
     
     
         74 . The one or more computer-readable media of  claim 72 , wherein the MAC CE includes a plurality of index bits, wherein individual index bits correspond to individual transmission points of the CoMP Measurement Set to indicate if the individual transmission point is active for CSI feedback. 
     
     
         75 . The one or more computer-readable media of  claim 72 , wherein the MAC CE includes a plurality of index bits, wherein the index bits point to a bitmap of a pre-defined table including a plurality of bitmaps, the bitmap indicating the activated transmission points. 
     
     
         76 . The one or more computer-readable media of  claim 72 , wherein the MAC CE further indicates a CoMP mode to be used by the UE. 
     
     
         77 . A method to manage coordinated multi-point (CoMP) communications with a user equipment (UE) on a wireless communications network comprising:
 transmitting, to the UE via radio resource control (RRC) signaling, channel state information (CSI) reference signal (RS) parameters for a plurality of transmission points; and   transmitting, to the UE, a medium access control (MAC) control element (CE) including a plurality of index bits that point to a bitmap of a pre-defined table including a plurality of bitmaps, the bitmap indicating one or more activated transmission points of the plurality of transmission points for which the UE is to generate CSI-RS feedback.   
     
     
         78 . The method of  claim 77 , wherein individual bits of the bitmap correspond to individual transmission points of the CoMP Measurement Set to indicate if the individual transmission point is active for CSI feedback.