Abstract: Systems and methods for Semi-Persistent Sounding Reference Signal (SP SRS) resource activation or deactivation are disclosed. In some embodiments, a method of operation of a wireless device in a cellular communications network comprises receiving, from a network node, a Medium Access Control (MAC) Control Element (CE). The MAC CE comprises an indication of a SP SRS resource set to be activated or deactivated and information that indicates a spatial relation for the SP SRS resource set to be activated or deactivated. In this manner, a MAC CE for SP SRS resource set activation or deactivation is provided in a manner that gives spatial relation information in an efficient and flexible manner.

Abstract: Systems and methods for activating a Semi-Persistent (SP) Zero Power (ZP) Channel State Information Reference Signal (CSI-RS) are provided. In some embodiments, a method performed by a wireless device includes for activating SP ZP CSI-RS includes receiving, from a network node, a control message that indicates the activation of one or more SP ZP CSI-RS resources; and activating, based on the control message, the one or more SP ZP CSI-RS resources. In this way, ZP CSI-RS may be used for rate matching around other wireless devices and a SP ZP CSI-RS resource may be activated without activating any Non-Zero Power (NZP) CSI-RS, CSI-Interference Measurement (CSI-IM), or CSI reporting for the wireless device.

Abstract: Embodiments provide a feedback indicator for coordinated multi-point operations of various coordinated multi-point schemes and/or scenarios. An exemplary embodiment involves generating a feedback indicator for coordinated multi-point operations, the feedback indicator indicating a recommendation for a CoMP controller entity to request signaling of multi-point feedback information with respect to multiple coordinated multi-point transmission points, and signaling the generated feedback indicator for coordinated multi-point operations to the CoMP controller entity.

Abstract: An apparatus and method for selecting a beam group and a subset of beams in a communication system are disclosed. The method includes: measuring channel state information (CSI) on a downlink from a base station (920); identifying a selected beam group out of a set of beam groups according to a wideband property of the CSI (930); identifying a selected subset of beams in the selected beam group according to at least one subband (940). Wherein the characteristic of the set of beam groups depends on a transmission rank and the number of beams in the selected subset of beams is equal to the transmission rank. The method further includes: generating encoded feedback information identifying the selected beam group and the selected subset of beams for each subband in a double codebook format (950), transmitting the encoded feedback information to the base station.

Abstract: A first precoding matrix W1 is selected from a first codebook comprising sets of rank specific precoding matrices. The first codebook is characterized by there being fewer precoding matrices associated with higher ranks than associated with lower ranks, and characterized by precoding matrices associated with ranks above a certain rank all being diagonal matrices. The selected first precoding matrix W1 is used to select a rank-specific second precoding matrix W2 from a second codebook, such that the selected first and second precoding matrices form a joint precoder specific to a desired rank. The second codebook is characterized by differently sized precoding matrices associated with each of N total ranks, in which N is an integer greater than one. Information on the joint precoder is reported to a network node over an uplink transmission channel.

Abstract: An apparatus and a method are provided, which, for example in a user equipment, measure a transmission channel based on reference resources with respect to at least two transmission points, establish a feedback report based on the measurement, the feedback report including a plurality of channel feedback information related to each transmission point, and send the feedback report on a physical uplink control channel.

Abstract: To control UE assumption of interference there is a controller module to control a plurality of transmission points, each constituted by a set of at least one transmit antenna, to transmit data to another device in a coordinated transmission from at least a subset of the plurality of transmission points. The controller module is configured to allocate, to each resource linked to the subset of the plurality of transmission points, an interference contribution parameter that is indicative of an expected interference contribution originating from said transmission point, and to inform said another device of those resources to which the subset of the plurality of transmission points is linked, together with the respective interference contribution parameter allocated to each resource. Another device reports feedback based on signals which are scaled with the respective interference contribution parameter.

Abstract: For coordinated multipoint transmission arrangements there is provided a device, including a controller module, configured to control a plurality of transmission points, each constituted by a set of at least one transmit antenna, to transmit data to another device in a coordinated transmission from at least a subset of the plurality of transmission points, wherein each subset with resources allocated thereto defines a respective coordinated transmission scheme, wherein the controller module is configured to transmit information on resources pertaining to multiple coordinated transmission schemes, and send at least one biasing parameter associated to at least one of the transmission schemes, to be applied for biasing a channel quality parameter. Another device includes a controller module, configured to report feedback responsive to such coordinated transmission, and the controller module is, among others, configured to apply the at least one biasing parameter to derived channel quality parameters.

Abstract: An apparatus and method for selecting a beam group and a subset of beams in a communication system are disclosed. The method includes: measuring channel state information (CSI) on a downlink from a base station (920); identifying a selected beam group out of a set of beam groups according to a wideband property of the CSI (930); identifying a selected subset of beams in the selected beam group according to at least one subband (940). Wherein the characteristic of the set of beam groups depends on a transmission rank and the number of beams in the selected subset of beams is equal to the transmission rank. The method further includes: generating encoded feedback information identifying the selected beam group and the selected subset of beams for each subband in a double codebook format (950), transmitting the encoded feedback information to the base station.

Abstract: A first precoding matrix W1 is selected from a first codebook comprising sets of rank specific precoding matrices. The first codebook is characterized by there being fewer precoding matrices associated with higher ranks than associated with lower ranks, and characterized by precoding matrices associated with ranks above a certain rank all being diagonal matrices. The selected first precoding matrix W1 is used to select a rank-specific second precoding matrix W2 from a second codebook, such that the selected first and second precoding matrices form a joint precoder specific to a desired rank. The second codebook is characterized by differently sized precoding matrices associated with each of N total ranks, in which N is an integer greater than one. Information on the joint precoder is reported to a network node over an uplink transmission channel.