Abstract: A method performed by a wireless device (510, 700, 1100) is disclosed. The wireless device obtains (601) a configuration for a sub-band channel quality indicator (CQI) granularity and a sub-band precoding matrix indicator (PMI) granularity for the wireless device. The wireless device determines (602) channel state information (CSI) feedback according to the configured sub-band CQI granularity and the sub-band PMI granularity. The sub-band PMI granularity corresponds to a first sub-band size and the sub-band CQI granularity corresponds to a second sub-band size. The first sub-band size is smaller than the second sub-band size. The wireless device transmits (603), to a network node (560, 1000), the determined CSI feedback.

Abstract: There is provided mechanisms for transmitting uplink reference signals. A method is performed by a terminal device. The method comprises obtaining, from a network node, a configuration of transmission of the uplink reference signals. The configuration comprises an indication of a first frequency interval in which the uplink reference signals are to be transmitted. The method comprises distributing transmission power available for transmitting the uplink reference signals over the first frequency interval based on channel information for the first frequency interval. The method comprises transmitting the uplink reference signals in accordance with the distributed transmission power.

Abstract: The present disclosure relates to a method performed by a wireless node (100) for transmitting reference symbols, the node comprising an antenna with a plurality of antenna ports, the method comprising configuring channel state information, CSI, measurements of a user equipment, UE (110), by transmitting a downlink message, transmitting a first reference symbol using the plurality of antenna ports, wherein the first reference symbol is transmitted using a first number N of antenna ports, transmitting a second reference symbol using the plurality of antenna ports, wherein the second reference symbol is transmitted using a second number K of antenna ports, wherein the first reference symbol is transmitted using a first port distance smaller than a second port distance used when transmitting the second reference symbol, and wherein the K used antenna ports are less than the N used antenna ports.

Abstract: A method performed by a wireless device (510, 700, 1000) for transmitting a channel state information (CSI) report for a downlink channel comprises obtaining (601) a first set of candidate frequency-domain components and determining (602) a set of spatial-domain components. The method comprises determining (603) a second set of candidate frequency-domain components as a subset of the first set of candidate frequency-domain components. The method comprises determining (604), for each spatial-domain component of the set of spatial-domain components, a spatial-domain component-specific set of frequency-domain components as a subset of the second set of candidate frequency-domain components. The method comprises transmitting (605), to a network node (560, 900), the CSI report.

Abstract: A method performed by a wireless device (510, 800, 1200) for reporting channel state information (CSI) for a downlink channel is disclosed. The method comprises transmitting (601, 705) a CSI report for the downlink channel to a network node (560, 1100), the CSI report comprising: a set of reported coefficients; an indication of how the network node is to interpret the set of reported coefficients; and an indication of a payload size of the set of the reported coefficients.

Abstract: There is disclosed a method of operating a measuring radio node in a wireless communication network, the method includes transmitting signaling based on delay spread information, the delay spread information being based on and/or representing delay spread associated to received reference signaling. There are also disclosed related devices and method.

Abstract: According to some embodiments, a method is performed by a user equipment for reporting channel state information. The user equipment is configured with two or more channel state information reference signal, CSI-RS, resources in a CSI-RS resource set. The method comprises: selecting at least two CSI-RS resources from the CSI-RS resource set, wherein each of the at least two selected CSI-RS resources are associated to a set of spatially multiplexed layers, wherein different sets comprise different layers; determining a preferred precoder matrix for the selected CSI-RS resources; and transmitting a CSI report indicating the selected CSI-RS resources and the preferred precoder matrices. The method may further comprise calculating a channel estimate for the selected CSI-RS resources, and determining a channel quality indicator, CQI, corresponding to a hypothetical transmission from a plurality of effective channels where layers transmitted through the effective channels mutually interfere.

Abstract: Methods and apparatuses are disclosed for restricting SRS power control configurations. In one embodiment, a method implemented in a wireless device, WD, is provided. The method includes obtaining at least a first sounding reference signal, SRS, resource set configuration for a first SRS resource set, the first SRS resource set configuration corresponding to a first SRS transmission power value; obtaining at least a second SRS resource set configuration for a second SRS resource set, the second SRS resource set configuration corresponding to a second SRS transmission power value; and determining a power level to transmit an SRS on at least one SRS resource associated with at least one of the first SRS resource set and the second SRS resource set.

Abstract: According to some embodiments, a method performed by a wireless device for transmitting on a plurality of antennas comprises signaling, to a network node, a wireless device power transmission capability. The wireless device power transmission capability identifies a power ratio value of a plurality of power ratio values that the wireless device supports for transmission of a physical uplink channel. Each value of the plurality of power ratio values corresponds to a transmission power capability and to a number of antenna ports. A power ratio refers to a ratio relative to a maximum power the wireless device is rated to transmit. The method further comprises transmitting a physical uplink channel using the number of antenna ports with a power scaled at least by the power ratio value.

Abstract: According to one embodiment, a method at a transmitting device is provided. The method includes transmitting at least two groups of reference signals, wherein a first and a second group of the at least two groups each correspond to transmission on a plurality of antenna ports, the first group corresponds to a smaller number of antenna ports than the second group. The maximum combined power on the antenna ports may correspond to the first and second group is substantially the same. One or more of the antenna ports corresponding to the first group may be formed according to at least one of a first and a second mechanism. User equipment and base station comprising processing circuitry to perform steps of method according to the various embodiments are also provided.

Abstract: In certain embodiments, a method performed by a wireless device comprises estimating a channel state of a downlink channel and transmitting a CSI report for the downlink channel based on the channel state. The CSI report indicates a plurality of precoder vectors, each corresponding to a frequency sub-band of the bandwidth of the downlink channel, a precoder vector being expressed as a linear combination of spatial-domain components and frequency-domain component wherein each of the spatial-domain components is associated with a respective set of one or more frequency-domain components.

Abstract: A technique for transmitting reference signals (RS), from a first station using a transmit antenna (400) with a number of antenna ports to a second station for determining channel state information (CSI), of a radio channel between the first station and the second station is described. As to a method aspect of the technique, a first set of precoders (502) is defined for the number of antenna ports. Based on the first set, a second set of precoders (702) is derived for the number of antenna ports. A second rank of the second set of precoders (502) is different from a first rank of the first set of precoders (702). The second rank of the second set is less than the number of antenna ports (402). Each of the antenna ports is associated with non-zero energy by at least one of the precoders (702) of the second set. The RS are transmitted using each of the precoders (702) of the second set.

Abstract: A method performed by a wireless device (510, 700, 1100) is disclosed. The wireless device obtains (601) a configuration for a sub-band channel quality indicator (CQI) granularity and a sub-band precoding matrix indicator (PMI) granularity for the wireless device. The wireless device determines (602) channel state information (CSI) feedback according to the configured sub-band CQI granularity and the sub-band PMI granularity. The sub-band PMI granularity corresponds to a first sub-band size and the sub-band CQI granularity corresponds to a second sub-band size. The first sub-band size is smaller than the second sub-band size. The wireless device transmits (603), to a network node (560, 1000), the determined CSI feedback.

Abstract: There is disclosed a method for operating a transmitting node of a wireless communication network, the transmitting node being adapted for a plurality of beamforming states, wherein the method comprises transmitting reference signaling based on a beamforming state of the transmitting node. There are also disclosed related nodes and methods.

Abstract: A method performed by a wireless device (510, 700, 1100) is disclosed. The wireless device obtains (601) a configuration for a sub-band channel quality indicator (CQI) granularity and a sub-band precoding matrix indicator (PMI) granularity for the wireless device. The wireless device determines (602) channel state information (CSI) feedback according to the configured sub-band CQI granularity and the sub-band PMI granularity. The sub-band PMI granularity corresponds to a first sub-band size and the sub-band CQI granularity corresponds to a second sub-band size. The first sub-band size is smaller than the second sub-band size. The wireless device transmits (603), to a network node (560, 1000), the determined CSI feedback.

Abstract: A method performed by a base station of enabling a User Equipment (UE) to determine a precoder codebook in a wireless communication system is provided. The base station transmits, to the UE, information regarding precoder parameters enabling the UE to determine the precoder codebook. The precoder parameters are associated with a plurality of antenna ports of the base station. The precoder parameters relate to a first dimension and a second dimension of the precoder codebook. The plurality of antenna ports comprises a number of antenna ports that is a function of a number of antenna ports in the first dimension, and a number of antenna ports in the second dimension.

Abstract: There is provided mechanisms for transmitting uplink reference signals. A method is performed by a terminal device. The method comprises obtaining, from a network node, a configuration of transmission of the uplink reference signals. The configuration comprises an indication of a first frequency interval in which the uplink reference signals are to be transmitted. The method comprises distributing transmission power available for transmitting the uplink reference signals over the first frequency interval based on channel information for the first frequency interval. The method comprises transmitting the uplink reference signals in accordance with the distributed transmission power.

Abstract: A user equipment (UE) (200, 500, 1530) transmits data to a base station (100, 500, 1520) in a wireless communication network. The UE (200, 500, 1530) comprises multiple antenna ports, and selects a precoding matrix from a respective first, second, third, or fourth set of precoding matrices according to a number of spatial layers. The first, second, third, and fourth sets of precoding matrices are available for all coherence capabilities and are comprised within a larger set of precoding matrices. The larger set comprises precoding matrices that are not available for all coherence capabilities. The first, second, third, and fourth sets of precoding matrices correspond to one, two, three, or four spatial layers, respectively. The number of columns in the selected precoding matrix is equal to the number of spatial layers and each column comprises a single non-zero element and one or more zero elements.

Abstract: A network node signals to a wireless communication device which precoders in a codebook are restricted from being used. The network node in this regard generates codebook subset restriction signaling that, for each of one or more groups of precoders, jointly restricts the precoders in the group by restricting a certain component (e.g., a certain beam precoder) that the precoders in the group have in common. This signaling may be for instance rank-agnostic signaling that jointly restricts the precoders in a group without regard to the precoders' transmission rank. Regardless, the network node sends the generated signaling to the wireless communication device.

Abstract: A method performed by a base station of enabling a User Equipment (UE) to determine a precoder codebook in a wireless communication system is provided. The base station transmits, to the UE, information regarding precoder parameters enabling the UE to determine the precoder codebook. The precoder parameters are associated with a plurality of antenna ports of the base station. The precoder parameters relate to a first dimension and a second dimension of the precoder codebook. The plurality of antenna ports comprises a number of antenna ports that is a function of a number of antenna ports in the first dimension, and a number of antenna ports in the second dimension.