Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung E.v.

Venkatesh Ramireddy

Markus Landmann

Marcus Grossmann

Marcus Großmann

Sutharshun Varatharaajan

Florian Römer

Marcus Grobmann

Marcus Groβmann

A communication device for providing a channel state information, CSI, feedback in a wireless communication system includes a transceiver to receive, from a transmitter a radio signal via a time-variant, frequency-selective MIMO channel, the radio signal including downlink reference signals according to a reference signal configuration including a number of antenna ports, and downlink signals including the reference signal configuration; and a processor. The processor estimates an explicit CSI in the frequency domain using measurements on the downlink reference signals on the radio channel, selects a Doppler-delay precoder matrix (W) for a composite Doppler-delay-beam three-stage precoder, calculates either one or more of a channel quality indicator, CQI, and/or a precoder matrix indicator, PMI, and/or a rank indicator, RI, and reports to the transmitter the CSI feedback including either one or more of the CQI, and/or the PMI and/or the RI.

Doppler-delay codebook-based precoding and CSI reporting for wireless communications systems

A user device, UE, for a wireless communication network is configured or preconfigured with one or more Sounding Reference Signal, SRS, resources to be used for SRS transmissions. The one or more SRS resources include a plurality of frequency domain resources. Responsive to receiving an indication of a subset of SRS frequency domain resources for each resource, the UE performs an SRS transmission using the indicated subset of frequency domain resources.

Flexible SRS sounding for NR systems

A communication device providing CSI feedback in a wireless communication system includes a transceiver to receive downlink reference signals and downlink signals including a reference signal configuration. A processor estimates an explicit CSI in the frequency domain. The processor selects a Doppler-delay-beam precoder matrix for a composite Doppler-delay-beam three-stage precoder, which is based on one or more codebooks including

Doppler codebook-based precoding and CSI reporting for wireless communications systems

A communication device for providing an explicit channel state information, CSI, feedback in a wireless communication system includes a transceiver to receive, from a transmitter a radio signal via a radio time-variant frequency MIMO channel, the radio signal including downlink reference signals according to a reference signal configuration, and downlink signals including the reference signal configuration, and a processor. The processor estimates the CSI using measurements on the downlink reference signals of the radio channel according to the reference signal configuration over one or more time instants/slots, constructs a frequency-domain channel tensor using the CSI estimate, performs a higher-order principal component analysis, HO-PCA, on the channel tensor, identifies a plurality of dominant principal components of the channel tensor, thereby obtaining a compressed channel tensor, and reports to the transmitter the explicit CSI including the dominant principal components of the channel tensor.

Explicit channel information feedback based on high-order PCA decomposition or PCA composition

A method performed by a UE for generating a CSI report in a wireless communication system, including receiving from a network node, a CSI report configuration information including at least one parameter, D, for indicating a first basis set of D basis vectors used for constructing for each transmission layer a precoding vector or matrix for a rank set; identifying a precoding vector matrix for each transmission layer based on the first basis set, a second basis set comprising P basis vectors, and a number of combining coefficients for combining selected vectors from the first and second basis sets; generating a CSI report based on the CSI report configuration information for a RI, or v of the rank set; and transmitting the CSI report to the network node.

CSI reporting based on linear combination codebook

The present disclosure relates to methods and apparatuses (UE, network node or gNB) for CSI reporting. The method performed by a UE comprises: receiving from the gNB, a radio signal via a MIMO channel, wherein the radio signal contains at least one DL-RS according to a DL-RS configuration; estimating said MIMO channel based on said received at least one DL reference signal for configured subbands; calculating a precoder matrix or a CSI matrix for a number of antenna ports of the gNB and configured subbands; the precoder matrix based on a first codebook and on a second codebook and a set of combining coefficients for complex scaling/combining one or more of vectors selected from the first codebook and the second codebook; and reporting, to the gNB, a CSI feedback report and/or a PMI/RI, used to indicate the precoder matrix or the CSI matrix for the configured antenna ports and subbands.

Methods and apparatuses for enhancement on basis subset indication for two-codebook based CSI reporting

A receiver processes a radio signal received via a radio channel from a transmitter employing a plurality of antenna ports, determines complex precoder coefficients and delays of one or more space-delay precoders for one or more transmission layers and antenna ports at the transmitter so as to achieve a predefined property for a communication over the radio channel, and feeds back, explicitly or implicitly, delays and the complex precoder. The space-delay precoder has a dual-stage structure having a spatial codebook matrix including spatial beamforming vectors, a frequency-domain codebook matrix, and a combining element per layer for complex scaling or combining one or more of the vectors selected from the spatial and/or frequency-domain codebook matrices. The frequency-domain codebook matrix is defined by a sub-matrix of a DFT matrix, which the sub-matrix of the DFT matrix is associated with a range of delay values.

Receiver, transmitter, system and method employing space-delay precoding

Doppler-delay codebook-based precoding and CSI reporting wireless communications systems

A communication device for providing a channel state information, CSI, feedback in a wireless communication system includes a transceiver to receive a radio signal including downlink reference signals. The processor The communication device selects from one or more codebooks a subset of D delay components and/or a subset of F Doppler-frequency components and uses the selected subset of delay components for each polarization and each spatial beam and/or the selected subset of Doppler-frequency components for each polarization, each spatial beam and each delay, when calculating the Doppler-delay precoder matrix.

CSI reporting and codebook structure for doppler-delay codebook-based precoding in a wireless communications system

A receiver includes an antenna for a wireless communication with a transmitter and a signal processor to process a radio signal received via a radio channel. The receiver constructs a codebook including sets of beamforming weights for a plurality of directions. The beamforming weights are based on a first antenna array response matrix of a transmitter antenna array. The transmitter selects beamforming weights from the codebook to form a transmit/receive beam pointing in a selected direction. The receiver calculates one or more characteristic matrices based on a model of the transmitter antenna array, and constructs the codebook using a second antenna array response matrix and the one or more calculated characteristic matrices.

Antenna array codebook with beamforming coefficients adapted to an arbitrary antenna response of the antenna array

A receiver receives and processes a radio signal received via a frequency selective radio channel from a transmitter employing a plurality of transmit antennas. The receiver determines, based on the received signal, complex precoder coefficients and delays of respective space-delay precoders for each layer and transmit antenna at the transmitter so as to achieve a predefined property for a communication over the radio channel, each space-delay precoder modeling or defining for the associated transmit antenna a plurality of cyclic filters delaying and weighting a signal to be transmitted with the corresponding precoder delays and complex precoder coefficients, respectively, and feeds back to the transmitter the determined delays explicitly or implicitly and the determined complex precoder coefficients explicitly or implicitly, the transmitter precoding the signals to be transmitted to the receiver using the fed back delays and complex precoder coefficients.

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Erlangen, Germany

Venkatesh Ramireddy