Patent ID: 11936456
Assignee: FRAUNHOFER GESELLSCHAFT ZUR FÖRDERUNG DER ANGEWANDTEN FORSCHUNG E.V.
Field: Telecommunications (Electrical engineering)
Classification: CPC H | IPC H

Claim 7:
8. A method performed by a user equipment (UE) for providing channel state information (CSI) feedback in a form of one or more CSI reports in a wireless communication system (A), the method comprising:
receiving, from a network node (gNB) higher layer configuration(s) of one or more downlink reference signals, and one or more CSI report configuration(s) associated with the downlink reference signal configuration(s), and a radio signal, the radio signal including the downlink reference signal(s) according to the one or more downlink reference signal configuration(s),
the downlink reference signal(s) being provided over a configured number of frequency domain resources, time domain resources and one or more ports;
determining, for each CSI report, a precoding matrix based on the downlink reference signal(s) and two codebooks, the two codebooks including
a spatial codebook comprising one or more spatial domain (SD) basis components of a precoder, and
a delay codebook comprising one or more delay domain (DD) basis components of the precoder,

and one or more non-zero combining coefficients for complex combining of the one or more SD and DD basis vectors; and
reporting, to the network node, the one or more CSI reports for the one or more CSI report configurations,, wherein each CSI report contains a selected precoding matrix in the form of a precoding matrix identifier (PMI) and a rank identifier (RI) indicating the transmission rank for the RI layers of the precoding matrix, and wherein each CSI report comprises two parts: CSI part 1 and CSI part 2, wherein part 1 has a fixed payload size and comprises information indicating the size of the payload of part 2, wherein part 2 comprises at least the amplitude and phase information of the selected non-zero combining coefficients of the CSI report, and wherein a portion, or the entirety, of part 2 is available for omission from the CSI report, wherein CSI part 2 contains at least the following information for the RI layers of the selected precoding matrix:
a spatial domain (SD) basis subset indicator, including, if configured, the rotation oversampling factors, indicating the selected SD basis vectors from the spatial codebook,
one or more delay domain (DD) basis subset indicators indicating the selected DD basis vectors from the delay codebook,
the phase and amplitude of the selected non-zero delay-domain combining coefficients,
a strongest coefficient indicator (SCI) indicating the DD and SD vector associated with the strongest coefficient per layer,
a polarization reference amplitude per layer,
a bitmap for indicating the non-zero combining coefficients per layer, and
possible additional parameter(s) associated with the DD basis subset indication.