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: 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 selecting a transmission hypothesis. A method is performed by a terminal device. The method comprises receiving reference signals from at least two transmission and reception points (TRPs). The method comprises selecting, from signal quality measurements on the reference signals, a transmission 5 hypothesis from alternative transmission hypotheses pertaining to which one or more of the TRPs that is to transmit data to the terminal device. Which of the transmission hypotheses to select is affected by an adjustment term. The method comprises reporting an indication of the selected transmission hypothesis to at least one of the at least two TRPs.

Abstract: There is provided an antenna arrangement having unequally many physical antenna elements for transmission and reception. The antenna arrangement comprises physical antenna elements. All physical antenna elements are configured for signal reception but less than all of the physical antenna elements are configured for both signal transmission and signal reception. A first portion of those physical antenna elements configured for both signal transmission and signal reception and a second portion of those physical antenna elements configured for both signal transmission and signal reception are in the antenna arrangement placed to, during operation of the antenna arrangement, be vertically separated by physical antenna elements configured for only signal reception.

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 network node determines parameters indicating a compression function for compressing downlink channel estimates, and a decompression function. The network node transmits the parameters, receives compressed downlink channel estimates, and decompresses the compressed downlink channel estimates using the decompression function. A terminal device receives the parameters, forms the compression function, compresses downlink channel estimates using the compression function, and transmits the compressed downlink channel estimates. The compression function comprises a first function formed based on at least some of the parameters, a second function which is non-linear, and a quantizer. The first function is configured to receive input data, and to reduce a dimension of the input data. The decompression function comprises a first function configured to receive input data and provide output data in a higher dimensional space than the input data, and a second function which is non-linear.

Abstract: A network node (501) determines parameters (503) indicating a compression function for compressing downlink channel estimates, and a decompression function. The network node transmits the parameters, receives compressed downlink channel estimates (504), and decompresses the compressed downlink channel estimates using the decompression function. A terminal device (502) receives the parameters, forms the compression function, compresses downlink channel estimates using the compression function, and transmits the compressed downlink channel estimates. The compression function comprises a first function formed based on at least some of the parameters, a second function which is non-linear, and a quantizer. The first function is configured to receive input data, and to reduce a dimension of the input data. The decompression function comprises a first function configured to receive input data and provide output data in a higher dimensional space than the input data, and a second function which is non-linear.

Abstract: A method performed by a radio unit for handling a number of received radio signals over an array of antennas comprised in the radio unit. The radio unit transforms the number of received radio signals into a number of sequences of complex symbols. The radio unit further filters the number of sequences of complex symbols by inputting the number of sequences of complex symbols into a trained computational model comprising an alternating sequence of linear and nonlinear functions and thereby obtaining a reduced number of sequences. The radio unit further transmits the reduced number of sequences to a baseband unit over a front-haul link.

Abstract: A user equipment (UE) transmits over multiple antenna ports and receives a control message from a base station in a wireless communication network. The control message comprises a precoding matrix indication field configurable to a first, second, and third configuration. The first configuration identifies precoding matrices in both a first set of precoding matrices and a second set of precoding matrices. The second configuration identifies precoding matrices in the second set of precoding matrices but not in the first set of precoding matrices. The third configuration identifies precoding matrices in a third set of precoding matrices in addition to the first and second sets. The precoding matrices in the sets are precoding matrices for transmissions from the UE. Each set of precoding matrices corresponds to a respective coherence capability. For a maximum of four spatial layers, the first, second, and third configurations occupy 5, 4, and 6 information bits, respectively.

Abstract: A user equipment (UE) being configured to receive a downlink (DL) information, determine a spatial association for an uplink (UL) transmission based on the DL information, and determine UL power control (PC) parameters based on the DL information.

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: Embodiments provide methods, network nodes, and wireless devices for sounding reference signal (SRS) power control in New Radio (NR). According to one aspect, a wireless device (WD) is configured to receive signaling from the network node that identifies a first sounding reference signal, SRS, configuration defining an SRS resource set comprising one or more SRS resources. The WD is further configured to determine a first transmission power intended for SRS transmission, the determining being based at least in part on the first SRS configuration. The WD is also configured to determine a second transmission power for at least one antenna port related to the SRS resource set based on the first transmission power and according to a rule dependent on the first SRS configuration. The WD is also configured to transmit SRS on the at least one antenna port with the second transmission power.

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: According to certain embodiments, a method implemented in a wireless device comprises determining configuration data representing a set of configurations. The method comprises receiving at least one reference signal from a transmission point. The receiving of the at least one reference signal is performed in accordance with a configuration selected from the set, wherein the configuration is related to uplink power control and is specific to an uplink channel or signal or a group thereof. The method comprises measuring a propagation-related quantity on the basis of the at least one reference signal and deriving an uplink power setting on the basis of the measured propagation-related quantity.

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: Embodiments include methods for operating a network node in a wireless network. Such embodiments include applying non-linear precoding to a first data stream to remove a representation of expected inter-stream interference due to a second data stream, thereby generating a corrected first data stream. Such embodiments also include applying linear precoding to the corrected first data stream and to a first reference signal (RS) stream to generate a first signal layer, wherein the first RS stream is not corrected for the expected inter-stream interference prior to applying the linear precoding. Such embodiments also include transmitting the first signal layer to a user equipment (UE). Other embodiments include complementary methods performed by a UE, as well as network nodes and UEs configured to perform operations corresponding to such methods.

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: 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: Embodiments include methods, performed by a user equipment (UE), for transmitting or receiving a plurality of physical data channels in a wireless network. Such methods include receiving, from the wireless network, an indication of a Transmission Configuration Indicator (TCI) state that includes one or more source reference signal (RS) pairs. Each source RS pair has a pair of quasi-colocation (QCL) relations with antenna ports, for demodulation reference signals (DM-RS), that are mapped to a plurality of code-division multiplexing (CDM) groups. Such methods include receiving/transmitting the physical data channels based on the QCL relations for the source RS pairs of the indicated TCI state. Each physical data channel corresponds to a CDM group and is received/transmitted in association with the DM-RS having antenna ports mapped to the corresponding CDM group. Other embodiments include complementary methods performed by a wireless network, and UEs and wireless networks configured to perform such methods.

Abstract: A network node (501) determines parameters (503) indicating a compression function for compressing downlink channel estimates, and a decompression function. The network node transmits the parameters, receives compressed downlink channel estimates (504), and decompresses the compressed downlink channel estimates using the decompression function. A terminal device (502) receives the parameters, forms the compression function, compresses downlink channel estimates using the compression function, and transmits the compressed downlink channel estimates. The compression function comprises a first function formed based on at least some of the parameters, a second function which is non-linear, and a quantizer. The first function is configured to receive input data, and to reduce a dimension of the input data. The decompression function comprises a first function configured to receive input data and provide output data in a higher dimensional space than the input data, and a second function which is non-linear.