Abstract: Systems and methods for User Equipment (UE)-assisted precoder selection are provided. In one embodiment, a method implemented in a base station for transmitting data to a UE comprises transmitting, to the UE, Channel State Information Reference Signal (CSI-RS) on two sets of CSI-RS resources; receiving, from the UE, two sets of CSI; estimating a first channel capacity for the codebook-based precoder based on the first set of CSI and a second channel capacity for the non-codebook-based precoder based on the second set of CSI; selecting one precoder from the codebook-based precoder and the non-codebook-based precoder based on the first channel capacity and the second channel capacity; and performing data transmission to the UE using the selected precoder. Embodiments of the proposed solution enable selecting a best precoder from the codebook-based precoder and the non-codebook-based precoder.

Abstract: Embodiments described herein provided methods and apparatuses for determining Channel State Information Interference Measurement resources, CSI-IM resources, for interference measurement, wherein a New Radio, NR, base station is spectrum sharing with a Long Term Evolution, LTE, base station. A method in an NR base station includes determining a CSI-IM pattern for a CSI-IM resource, wherein the CSI-IM pattern is defined by one or more first OFDM symbols and a first frequency shift; and transmitting a Channel State Information Reference Signal, CSI-RS, according to a CSI-RS pattern, wherein the CSI-RS pattern is defined by a second OFDM symbol and a second frequency shift, wherein the first frequency shift and the second frequency shift do not overlap and wherein the one or more first OFDM symbols overlap with the second OFDM symbol.

Abstract: Embodiments of a method performed by a base station for adaptive Channel State Information (CSI) reporting configuration and/or Physical Resource Block (PRB) bundling and corresponding embodiments of a base station are disclosed. In some embodiments, a method performed by a base station comprises obtaining one or more parameters comprising one or more measurements of channel dispersiveness of a wireless channel between the base station and a User Equipment (UE), an uplink (UL) power-limited status of the UE, and/or an allocation bandwidth for the UE. The method further comprises selecting, based on the one or more parameters, a CSI report configuration for the UE and/or a PRB bundling configuration for the UE. The method further comprises transmitting, to the UE, information that indicates the selected CSI report configuration and/or information that indicates the selected PRB bundling configuration.

Abstract: According to one or more embodiments, a wireless device configured to report one of a plurality of predefined Channel Quality Indicator (CQI) values is provided. A maximum CQI value of the plurality of predefined CQI values corresponds to any one of a plurality of signal characteristic values greater than or equal to a threshold signal characteristic value. The wireless device includes processing circuitry configured to determine a first signal characteristic value associated with a received signal. The processing circuitry is further configured to if the first signal characteristic value is greater than or equal to the threshold signal characteristic value associated with the maximum CQI value, generate a CQI report indicating: the maximum CQI value, and a power backoff from the first signal characteristic value that results in the threshold signal characteristic value.

Abstract: Systems and methods are disclosed herein for multi-user pairing and, in some embodiments, Signal to Interference plus Noise Ratio (SINR) calculation in a cellular communications system. In some embodiments, a method performed in a base station of a cellular communications system to perform downlink scheduling for Multi-User Multiple Input Multiple Output (MU-MIMO) comprises, for each User Equipment (UE) of a plurality of UEs considered for MU-MIMO UE pairing, obtaining a relative beam power at the UE for each of the plurality of beams. The relative beam power at the UE for each beam is a value that represents a relative beam power of the beam at the UE relative to a beam power of a strongest of the plurality of beams at the UE. The method further comprises selecting a MU-MIMO UE pairing based on the obtained relative beam powers.

Abstract: Embodiments described herein provided methods and apparatuses for determining Channel State Information Interference Measurement resources, CSI-IM resources, for interference measurement, wherein a New Radio, NR, base station is spectrum sharing with a Long Term Evolution, LTE, base station. A method in an NR base station includes determining a CSI-IM pattern for a CSI-IM resource, wherein the CSI-IM pattern is defined by one or more first OFDM symbols and a first frequency shift; and transmitting a Channel State Information Reference Signal, CSI-RS, according to a CSI-RS pattern, wherein the CSI-RS pattern is defined by a second OFDM symbol and a second frequency shift, wherein the first frequency shift and the second frequency shift do not overlap and wherein the one or more first OFDM symbols overlap with the second OFDM symbol.

Abstract: Apparatuses and methods are disclosed for Channel State Information Reference Signal (CSI-RS) resource mapping. According to one embodiment, a method in a network node includes allocating at least one resource for CSI Interference Measurement (CSI-IM) within a predetermined IM region of a Resource Block (RB) of the cell, the predetermined IM region encompassing a plurality of resources of the RB of the cell, the allocated at least one resource being selected from among the plurality of resources of the IM region to reduce a likelihood of overlap with at least one resource allocated for CSI-IM in a neighboring cell, the predetermined IM region at least partially overlapping with a respective predetermined IM region of a RB of the neighboring cell, and the predetermined IM region of the cell not overlapping resources allocated for Non-Zero Power Channel State Information Reference Signal (NZP CSI-RS) of the neighboring cell.

Abstract: A method, network node and wireless device (WD) for dual codebook configuration and channel state information (CSI) combining for large scale active antenna systems (AAS) are disclosed. According to one aspect, a method in a network node includes triggering the WD to transmit in succession or simultaneously, a horizontal CSI report reporting a horizontal CSI set for a horizontal direction of the array and a vertical CSI report reporting a vertical CSI set for a vertical direction of the array, the horizontal CSI set being mapped to a row of the array and the vertical CSI set being mapped to a column of the array. The method also includes receiving the horizontal and vertical CSI reports from the WD, and combining the horizontal and vertical CSI sets into a combined CSI set for at least one of scheduling and beamforming.

Abstract: A method of operating a network node includes receiving a first precoding matrix indicator, PMI, from a UE, wherein the first PMI is based on an antenna-grouping codebook, selecting a non-antenna-grouping codebook for downlink multi-user multiple input, multiple output, MU-MIMO transmission, determining a second PMI of the non-antenna-grouping codebook based on the first PMI of the antenna-grouping codebook, and performing MU-MIMO pairing and beamforming toward the UE based on the second PMI of the non-antenna-grouping codebook. Related network nodes are disclosed.

Abstract: Embodiments of a method in a base station configured to transmit and receive wireless signals to and from a user equipment, UE. A downlink channel response of a first UE antenna is determined, based on uplink signals received from the UE. First preceding weights are calculated based on the determined channel response of the first UE antenna. Orthogonal or quasi-orthogonal preceding weights are determined based on the first preceding weights. First and second downlink signal layers are transmitted using the first preceding weights and the orthogonal or quasi-orthogonal preceding weights.

Abstract: Embodiments of the present disclosure provide methods and apparatus for power control. A method at a network node comprises determining a value of power back-off for a first wireless device based on at least one of a number of wireless devices including the first wireless device, wherein the wireless devices including the first wireless device are co-scheduled by the network node and an estimated max power increase in an overlap area where two or more beams are to be overlapped, wherein one of the two or more beams is for the first wireless device. The method further comprises transmitting a message or data over the beam for the first wireless device, wherein an output power of the beam for the first wireless device is controlled based on the value of power back-off for the first wireless device.

Abstract: A method and network node for timing error estimation and compensation for Fifth Generation (5G) New Radio (NR) downlink (DL) systems with uncalibrated antennas are provided. According to one aspect, a method in a network node includes transmitting a first Channel State Information Reference Signal (CSI-RS) having a first timing compensation and transmitting a second CSI-RS having a second timing compensation, receiving a CSI-RS resource indicator (CRI) in a CSI report from a wireless device (WD), and determining from the CRI which of the first and second timing compensation results in a greater spectrum efficiency.

Abstract: A network node, wireless device and methods for co-phasing for beamforming using co-phasing matrices for wireless communications are provided. In one example, a network node for co-phasing in beamforming for transmissions is provided. The network node includes processing circuitry including a processor and a memory where the memory contains instructions executable by the processor to configure the network node to: obtain co-phasing information associated with a wireless device, generate at least two co-phasing matrices based on the co-phasing information, and apply the at least two co-phasing matrices to at least two resource structures.

Abstract: According to one or more embodiments, a wireless device configured to report one of a plurality of predefined Channel Quality Indicator (CQI) values is provided. A maximum CQI value of the plurality of predefined CQI values corresponds to any one of a plurality of signal characteristic values greater than or equal to a threshold signal characteristic value. The wireless device includes processing circuitry configured to determine a first signal characteristic value associated with a received signal. The processing circuitry is further configured to if the first signal characteristic value is greater than or equal to the threshold signal characteristic value associated with the maximum CQI value, generate a CQI report indicating: the maximum CQI value, and a power backoff from the first signal characteristic value that results in the threshold signal characteristic value.

Abstract: Embodiments of a method in a base station configured to transmit and receive wireless signals to and from a user equipment, UE. A downlink channel response of a first UE antenna is determined, based on uplink signals received from the UE. First preceding weights are calculated based on the determined channel response of the first UE antenna Orthogonal or quasi-orthogonal preceding weights are determined based on the first preceding weights. First and second downlink signal layers are transmitted using the first preceding weights and the orthogonal or quasi-orthogonal preceding weights.

Abstract: Embodiments of a method performed by a base station for adaptive Channel State Information (CSI) reporting configuration and/or Physical Resource Block (PRB) bundling and corresponding embodiments of a base station are disclosed. In some embodiments, a method performed by a base station comprises obtaining one or more parameters comprising one or more measurements of channel dispersiveness of a wireless channel between the base station and a User Equipment (UE), an uplink (UL) power-limited status of the UE, and/or an allocation bandwidth for the UE. The method further comprises selecting, based on the one or more parameters, a CSI report configuration for the UE and/or a PRB bundling configuration for the UE. The method further comprises transmitting, to the UE, information that indicates the selected CSI report configuration and/or information that indicates the selected PRB bundling configuration.

Abstract: A method, base station and user equipment are disclosed. A base station configured to communicate with a plurality of user equipments is provided. The base station includes processing circuitry configured to: track a downlink signal subspace for each UE of the plurality of UEs, and determine a Multi-User Multiple-Input Multiple-Output, MU-MIMO, precoders based on the downlink signal subspace for each UE of the plurality of UEs. The MU-MIMO precoders are configured to at least in part suppress intra-cell MU-MIMO interference.

Abstract: A method, network node and wireless device to apply power backoff to the physical downlink shared channel (PDSCH) based at least in part on a power backoff value are provided. According to one aspect, a method in a wireless device (WD) includes determining a beamforming gain based at least in part on a difference 5 between a physical downlink shared channel, Determine A Beamforming Gain Of A Physical Downlink PDSCH, received power and a reference signal received power. The method also includes transmitting the determined beamforming gain to a network node.

Abstract: Systems and methods for estimating Signal-to-Noise Ratio (SNR) for Multi-User Multiple-Input and Multiple-Output (MU-MIMO) based on channel orthogonality. In some embodiments, a method performed by a radio access node includes obtaining a SU-MIMO signal quality measurement for at least a first user and an additional user; obtaining an indication of orthogonality between a channel of the first user and a channel of the additional user; and estimating a MU-MIMO signal quality measurement for the first user as if the first user and the additional user are paired with each other for a potential MU-MIMO transmission based on the SU-MIMO signal quality measurements and the indication of orthogonality. In this way, a computational complexity for the SINR estimation of MU-MIMO users can be greatly reduced. This may enable a large number of user pairing alternatives to be evaluated in practical wireless systems to achieve improved MU-MIMO performance.

Abstract: Methods, network nodes and wireless device for setting an electrical tilt of an antenna array toward a distribution of wireless devices are disclosed. According to one aspect, a method includes for each of at least one sector of an area covered by the antenna array, determining a function of precoding matrix indicators, PMIs, received from a plurality of WDs in the sector. The method includes determining a current electrical tilt angle of the sector based on the function of PMIs. The method further includes comparing a difference between the current electrical tilt angle of the sector and a previously determined electrical tilt angle of the antenna array to a first threshold, and setting the electrical tilt angle of the antenna array based on the comparison.