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 for phase error compensation for Fifth Generation downlink systems with four correlated uncalibrated antennas are provided. A method includes applying N incremented phase rotations to one of the four antennas to produce N channel state information reference signal resources, N being an integer greater than 1. The method also includes transmitting N CSI-RS on 4 CSI-RS ports to a wireless device, WD, each of the N CSI-RS resources being transmitted with a different one of the incremented phase rotations. The method further includes receiving from the WD a CSI-RS resource indication that indicates a particular one of the N CSI-RS resources. The method also includes applying, in subsequent transmissions to the WD, a phase rotation to the one of the four antennas, the phase rotation corresponding to the indicated CSI-RS resource.

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: Embodiments of the present disclosure provide methods, apparatuses, and computer products for a base station. A method includes retrieving a plurality of phase rotations associated with a codebook for precoding matrix indicator, PMI, feedback; transmitting, to a User Equipment, UE, a plurality of Channel State Information Reference Signals, CSI-RSs, on a plurality of beams that correspond to the plurality of phase rotations; receiving, from the UE, a plurality of PMIs associated with the plurality of CSI-RSs, respectively, wherein the plurality of PMIs are indicative of a plurality of quantized precoding matrices from the codebook; using the plurality of quantized precoding matrices and the plurality of phase rotations to estimate phase and/or delay errors for a plurality of transmit antenna branches of the base station.

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, apparatuses, and computer products for base station antenna calibration. A method is implemented in a base station for a cellular communications system. The method includes selecting, from a plurality of User Equipments, UEs, assistant UEs to assist the base station with antenna calibration, wherein selecting the assistant UEs is based upon criteria that includes UE channel state information, CSI, from the UEs; one or more uplink channel characteristics of an uplink channel from the UEs to the base station; a UE capability of the UEs, UE traffic information related to the UEs; and any combination thereof. A further step is obtaining antenna calibration assistance information from the assistant UEs, the antenna calibration assistance information being information that is used by the base station for antenna calibration.

Abstract: Embodiments of the present disclosure provide methods and apparatuses for base station antenna calibration. A method is implemented in a base station for a cellular communications system. The method includes configuring a user equipment, UE, for a plurality of channel state information, CSI, reports associated to respective CSI reporting bands, the respective CSI reporting bands being either: (a) different subsets of sub-bands within a downlink bandwidth of the base station or (b) different downlink bandwidth parts served by the base station; receiving the CSI reports from the UE; estimating phase and delay errors for a plurality of transmit antenna branches of the base station; compensating for the estimated phase and delay errors for the transmit antenna branches based on the CSI reports received from the UE; and transmitting a downlink signal while compensating for the estimated phase and delay errors for the transmit antenna branches of the base station.

Abstract: According to one aspect, a network node configured to communicate with a wireless device is provided. The network node includes processing circuitry configured to: transmit a plurality of beamformed reference signals, each of the plurality of beamformed reference signals being associated with a respective sector of a cell; receive at least one uplink signal from the wireless device ; select one of the plurality of beamformed reference signals for the wireless device to monitor based at least in part on the received at least one uplink signal; and transmit an indication configured to cause the wireless device to monitor the selected one of the plurality of beamformed reference signals.

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: A method, network node and wireless device (WD) for New Radio (NR)-WD antenna calibration for Long Term Evolution (LTE)-NR radio-shared systems are disclosed. According to one aspect, a method in a network node configured to communicate with first wireless devices according to a first radio access technology and to communicate with second wireless devices according to a second radio access technology is provided. The method includes determining a delay and phase error at a first processing block based at least in part on feedback from at least one of the first wireless devices. The method also includes compensating a first transmitted signal based at least in part on the determined delay and phase error. The method further includes compensating at a second processing block a second transmitted signal based at least in part on the determined delay and phase error received from the first processing block.

Abstract: A method, network node and wireless device for phase error compensation for Fifth Generation downlink systems with four correlated uncalibrated antennas are provided. A method includes applying N incremented phase rotations to one of the four antennas to produce N channel state information reference signal resources, N being an integer greater than 1. The method also includes transmitting N CSI-RS on 4 CSI-RS ports to a wireless device, WD, each of the N CSI-RS resources being transmitted with a different one of the incremented phase rotations. The method further includes receiving from the WD a CSI-RS resource indication that indicates a particular one of the N CSI-RS resources. The method also includes applying, in subsequent transmissions to the WD, a phase rotation to the one of the four antennas, the phase rotation corresponding to the indicated CSI-RS resource.

Abstract: Methods and systems for mitigating channel quality indication (CQI) saturation in a channel state information (CSI) report received from a wireless device (WD) are disclosed. In one or more embodiments, a WD is provided. The WD includes processing circuitry configured to mitigate channel quality indication (CQI) saturation in a CSI report to a network node by at least in part receiving configuration information comprising in any one or more of: a power offset value, a number of channel state information reference signal, CSI-RS, ports, and a rank restriction. The WD then generates the CSI report such that the CSI report where the CSI report comprises a CQI value based CSI report comprises a CQI value based at least in part on the received configuration information and optionally causes transmission of the CSI report.

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: According to certain embodiments, a method for use in a network node for constructing an unsounded channel in a wireless network wherein the network node comprises more antennas than a wireless device and the wireless device comprises more than one receive antenna comprises: receiving channel state information (CSI) feedback and a sounded reference signal from the wireless device; estimating a sounded channel from the sounded reference signal; deriving a partial downlink channel based on the sounded reference signal; constructing an unsounded channel as a function of the CSI feedback and the partial downlink channel; concatenating the sounded channel and unsounded channel into a full channel; and transmitting a wireless signal to the wireless device using the full channel for beamforming or link adaptation.

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: A method and system for performing link adaptation are disclosed. According to one aspect, a method in a wireless communication system for performing link adaptation is provided. The method includes, when a first measure of channel quality is higher than a first predetermined amount, using a first outer loop adjustment process directed to determining link adaptation for a first data transmission transmitted to a wireless device. The method also includes, when the first measure of channel quality is lower than a second predetermined amount, using a second outer loop adjustment process different from the first outer loop adjustment process directed to determining link adaptation for a second data transmission transmitted to the wireless device.

Abstract: Methods and apparatuses for time-domain beam-sweeping are disclosed. In one embodiment, a method implemented in a wireless device (WD) includes receiving a CSI report configuration, the CSI-RS resource configuration and the CSI report configuration mapping each of a plurality of time-do-main beam sweeping CSI-RS transmissions in the configured one CSI-RS resource to a corresponding CSI report; receiving at least one of the plurality of time-domain beam sweeping CSI-RS transmissions in the configured one CSI-RS resource; and transmitting at least one CSI report according to the mapping. In another embodiment, a method in a network node includes determining a CSI-RS resource configuration for one CSI-RS resource; determining a CSI report configuration; and transmitting the plurality of time-domain beam sweeping CSI-RS transmissions in the configured one CSI-RS resource according to the mapping.

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: 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.