Abstract: There is provided mechanisms for transmission of reference signals. A method is performed by a terminal device. The terminal device comprises at least two physical antenna ports. The method comprises creating a virtual antenna port for, and applied over, at least two of the physical antenna ports. The method comprises transmitting, in the virtual antenna port, as many uplink reference signals as there are physical antenna ports.

Abstract: A method, system and apparatus for Type II precoder matrix indicator (PMI) for coherent joint transmission (CJT) are disclosed. According to one aspect, a method in a network node includes receiving from the wireless device (WD) a precoding matrix indicator (PMI), for coherent joint data transmission over a plurality of transmission reception points (TRPs) and one or both of a time difference and a phase slope associated with each TRP of the plurality of TRPs relative to a reference timing. The method also includes applying a time pre-compensation to a physical downlink channel at each of the plurality of TRPs according to at least one of the time difference and the phase slope associated with the TRP. The method also includes applying a precoding matrix indicated by the PMI to the physical downlink channel at each of the plurality of TRPs.

Abstract: Systems and methods are disclosed herein for spatial domain Channel State Information (CSI) compression for coherent joint transmission. In one embodiment, a method performed by a User Equipment (UE) comprises receiving information for a CSI report configuration that configures: (a) a plurality of Non-Zero Power (NZP) Channel State Information Reference Signal (CSI-RS) resources for channel measurement, wherein each of the plurality of NZP CSI-RS resources is associated with a different Transmission Configuration Indicator (TCI) state or unified TCI state; (b) a single NZP CSI-RS resource for channel measurement, wherein the single NZP CSI-RS resource comprising a plurality of sets of CSI-RS ports wherein each set of CSI-RS ports within the single NZP CSI-RS resource is associated with a different TCI state or unified TCI state; or (c) both (a) and (b).

Abstract: A technique for transmitting data on at least two subbands (602) of a radio channel (600). As to a method aspect of the technique performed by a radio device, control information indicative of at least two precoders for the at least two subbands (602) of the radio channel (600) is received. The data is transmitted on the at least two subbands (602) using the at least two precoders.

Abstract: There is provided a method performed by a user equipment (UE). The method comprises: receiving a reference signal over multiple time instances; determining time domain properties of a channel, based on the received reference signal; and sending a report to a network node, the report comprising information about the determined time domain properties of the channel. A UE for implementing this method is also provided.

Abstract: There is provided mechanisms for interference handling. A method is performed by a radio access network node. The method comprises obtaining an indication of interference in a time/frequency interval. The method comprises querying a neighbouring radio access network node about scheduling in the time/frequency interval of uplink wireless transmission from any terminal device served by the neighbouring radio access network node. The method comprises receiving a response from the neighbouring radio access network node. The response comprises information identifying uplink reference signal resources/ports, and their scheduling, as to be used by the terminal device scheduled in the time/frequency interval.

Abstract: A method, system and apparatus are disclosed. According to one or more embodiments, a wireless device configured to communicate with a network node implementing a plurality of Channel State Information-Reference Signal, CSI-RS, ports is provided. The wireless device includes processing circuitry configured to: receive a configuration of a CSI-RS resource that is associated with the plurality of CSI-RS ports, determine at least a subset of the plurality of CSI-RS ports for performing a CSI-RS measurement within the CSI-RS resource where the determination is based on a calculation using a total number of the plurality of CSI-RS ports and a ratio value, and perform the CSI measurement based on the determined subset of the plurality of CSI-RS ports.

Abstract: A method performed by a user equipment (UE) comprises receiving information that configures the UE with: (a) Non-Zero Power (NZP) Channel State Information Reference Signal (CSI-RS) resources for channel measurement each associated with a different Transmission Configuration Indicator (TCI) state or unified TCI state, (b) a single NZP CSI-RS resource for channel measurement comprising multiple sets of CSI-RS ports each associated with a different TCI state or unified TCI state, or both (a) and (b). The information further configures the UE with a parameter combination indicating at least a number of frequency domain (FD) basis vectors to be selected and reported per layer across the NZP CSI-RS resources or the sets of CSI-RS ports, or for each of the NZP CSI-RS resources or each of the of CSI-RS ports and a number of precoding matrix indicator (PMI) subbands. The method further comprises computing and reporting CSI accordingly.

Abstract: A method, network node and wireless device for channel state information (CSI) omission for Type II CSI are disclosed. According to one aspect, a method in a network node includes receiving from a wireless device (WD) an indication of a CSI reporting capability. The method includes configuring the WD to report frequency domain (FD) basis vector information in one of a CSI reporting Group 1 and a CSI reporting Group 0, based at least in part on the indicated CSI reporting capability.

Abstract: Embodiments include methods for a radio access network (RAN) node configured to serve one or more user equipment (UEs). Such methods include transmitting reference signals (RS) for a downlink (DL) channel and receiving, from a UE, a report including encoded feedback representing the DL channel. The encoded feedback comprises a UE DL channel estimate mapped to a channel feature set based on a first mapping that is proprietary to the UE. The channel feature set is compressed based on a second mapping that is known by the UE and the RAN node. Such methods also include, using a decoder function of a neural-network autoencoder (NNAE), decoding the encoded feedback to obtain a reconstruction of the channel feature set. Other embodiments include complementary methods for a UE, as well as RAN nodes and UEs configured to perform such methods.

Abstract: Embodiments include methods for a radio access network (RAN) node. Such methods include transmitting downlink (DL) reference signals (RS) in accordance with one or more configurations and receiving, from each of one or more user equipment (UEs), feedback representing a DL channel from the RAN node to the UE. The feedback is based on the UE's measurements of the transmitted DL RS and is encoded by one or more UE encoders that correspond to respective RAN node decoders. Such methods include, for each of the one or more UEs, obtaining one or more measurements of uplink (UL) RS transmitted by the UE in accordance with the one or more configurations. Such methods include training the RAN node decoder(s) based on the received feedback and the obtained UL RS measurements. Other embodiments include complementary methods for UEs, as well as RAN nodes and UEs configured to perform such methods.

Abstract: There is provided mechanisms for transmission of reference signals. A method is performed by a terminal device. The terminal device comprises at least two physical antenna ports. The method comprises creating a virtual antenna port for, and applied over, at least two of the physical antenna ports. The method comprises transmitting, in the virtual antenna port, as many uplink reference signals as there are physical antenna ports.

Abstract: There is provided mechanisms for transmission of reference signals. A method is performed by a terminal device. The terminal device comprises at least two physical antenna ports. The method comprises obtaining channel information. The method comprises determining, for at least one given precoder in a codebook, an uplink reference signal to physical antenna port mapping based on the channel information. The method comprises transmitting uplink reference signals in the physical antenna ports according to the determined mapping.

Abstract: A method for reducing the number of beams required per symbol. The method is performed by a base station (gNB). The method includes transmitting reference signals (RSs) and receiving a report from a UE (302), the report identifying a matrix. The method also includes using the identified matrix to transmit data to the UE or schedule the UE. The matrix identified by the UE is equal to (I) and Wps is a port selection matrix and (II) denotes the Kronecker product.

Abstract: A method (700) for precoding a signal. The method includes determining (s702), based on uplink, UL, measurements, a spatial domain (SD) precoding vector and a frequency domain (FD) precoding vector for a downlink (DL) transmission of the signal. The method also includes applying (s704) the FD precoding vector to the signal over subcarriers for carrying the signal, thus producing a modified signal. The method further includes applying (s706) the SD precoding vector to the modified signal to produce a precoded signal, wherein the SD precoding vector is common for all said subcarriers in one symbol.

Abstract: A method, network node and wireless device for reducing overhead of New Radio (NR) Type II channel state information (CSI) feedback using angle and delay reciprocity are disclosed. According to one aspect, a method in a wireless device (WD) includes receiving a configuration of CSI report setting that indicates frequency domain basis vectors from a discrete Fourier transform, CSI reference signal (RS) ports and a subset of pairs of spatial domain and frequency domain vectors for the NCSI-RS CSI-RS ports. The method also includes determining linear combination coefficients corresponding to the selected frequency domain basis vectors and the selected subset of CSI-RS ports, determining linear combination coefficients corresponding to the selected frequency domain basis vectors and the selected subset of pairs of vectors in the spatial domain and the frequency domain.

Abstract: There is provided mechanisms for transmission of reference signals. A method is performed by a terminal device. The terminal device comprises at least two physical antenna ports. The method comprises obtaining channel information. The method comprises determining, for at least one given precoder in a codebook, an uplink reference signal to physical antenna port mapping based on the channel information. The method comprises transmitting uplink reference signals in the physical antenna ports according to the determined mapping.

Abstract: According to certain embodiments, a method performed by a wireless device comprises determining a configuration for sounding reference signal (SRS) transmission. The configuration is determined at least in part based on information received from a network node. The method further comprises performing the SRS transmission according to the configuration.

Abstract: Methods for reporting Channel State Information (CSI) from a wireless device to a radio network node are provided. More specifically, the wireless device receives an indication indicating a subset of Frequency Domain (FD) basis vectors among a full set of FD basis vectors from the radio network node. Accordingly, the wireless device computes a CSI corresponding to an enhanced type II port selection codebook using the indicated subset of FD basis vectors and report the CSI to the radio network node. The methods disclosed herein make it possible to reduce complexity and signaling overheat for reporting CSI based on the selected subset of FD basis vectors.

Abstract: A method (800) performed by a base station (e.g., gNB). The method includes selecting (s802) a set of frequency domain (FD) basis vectors. The method also includes transmitting (s804) to a UE information identifying the selected FD basis vectors.