CSI triggering and configuration enhancements for partial-reciprocity based port selection codebook
A method, apparatus, and a computer-readable storage medium are provided for partial reciprocity-based adaptive port selection codebook configuration. A method, apparatus, and a computer-readable storage medium are provided for partial reciprocity-based adaptive port selection codebook configuration. In an example implementation, the method may include a user equipment receiving at least one channel state information reporting configuration from a network node, the at least one channel state information reporting configuration including precoding matrix indicator as reporting quantity and an adaptive port selection codebook configuration for the precoding matrix indicator and determining whether partial reciprocity operations for adaptive port selection precoding matrix indicator are activated, the determining based at least on information in a sounding reference signal (SRS) request field of a downlink control information, an active semi-persistent SRS, or a periodic SRS configured by higher layers.
1 . A method of communications, comprising:
receiving, with a user equipment, at least one channel state information reporting configuration from a network node, the at least one channel state information reporting configuration including precoding matrix indicator as reporting quantity and an adaptive port selection codebook configuration for the precoding matrix indicator, wherein the adaptive port selection codebook configuration includes an additional field indicating a number of downlink reference signals, ports and resources to be used when partial reciprocity operations are activated or deactivated;
determining, with the user equipment, whether partial reciprocity operations for adaptive port selection precoding matrix indicator are activated, the determining based at least on information in a sounding reference signal request field of a downlink control information, an active semi-persistent sounding reference signal, or a periodic sounding reference signal configured by higher layers; and
determining, with the user equipment, a port selection precoding matrix indicator based at least on interpreting of the adaptive port selection codebook configuration that the partial reciprocity operations are activated, wherein the interpreting of the adaptive port selection codebook configuration for the precoding matrix indicator includes determining dimensions of a precoder in spatial and frequency domains, time offset between sounding reference signal transmission and downlink reference signal measurements, a number of downlink reference signals ports to be measured, a number of quantization bits, and a maximum number of non-zero coefficients,
the method further comprising:
transmitting a sounding reference signal and the precoding matrix indicator, the precoding matrix indicator being determined based at least on interpreting of the adaptive port selection codebook configuration, to the network node,
wherein the sounding reference signal resource sets suitable for partial reciprocity-based port selection precoding matrix indicator reporting are determined based at least on a number of ports, a frequency domain density, and power level.
2 . The method of claim 1 , further comprising:
determining that partial reciprocity operations for the adaptive port selection precoding matrix indicator are deactivated; and
determining the port selection precoding matrix indicator based at least on interpreting of the adaptive port selection codebook configuration that the partial reciprocity operations are deactivated.
3 . The method of claim 1 , wherein the adaptive port selection codebook configuration includes an additional field pointing to a plurality of sounding reference signal resource sets or sounding reference signal trigger codepoints for the partial reciprocity operations,
wherein the adaptive port selection codebook configuration includes another additional field indicating a time offset between sounding reference signal transmission and downlink reference signal measurements when partial reciprocity operations are activated or deactivated.
4 . The method of claim 1 , wherein the precoding matrix indicator is computed based on interpretation of the adaptive port selection codebook configuration and included in uplink control information and transmitted to the network node.
5 . The method of claim 1 , wherein the at least one channel state information reporting configuration, including the adaptive port selection codebook configuration for the precoding matrix indicator, is received via radio resource control, and wherein the configuration is of a periodic, aperiodic, or a semi-persistent reporting type.
6 . The method of any of claim 1 , wherein the adaptive port selection codebook configuration includes a single codebook configuration interpreted differently depending on the information in the sounding reference signal request field in downlink control information, active semi-persistent sounding reference signal, or configured periodic sounding reference signal by higher layers, and on the indicated sounding reference signal resource sets in the adaptive port selection codebook configuration.
7 . The method of claim 1 , wherein the adaptive port selection codebook configuration includes at least a first codebook configuration and a second codebook configuration,
wherein the first codebook configuration is a sounding reference signal assisted port selection codebook configuration and the second codebook configuration is a sounding reference signal non-assisted port selection codebook configuration,
wherein the first codebook configuration or the second codebook configuration is activated depending on information in a sounding reference signal request field in downlink control information, active semi-persistent sounding reference signal, or configured periodic sounding reference signal by higher layers, and on indicated sounding reference signal resource sets or sounding reference signal request codepoints in the adaptive port selection codebook configuration.
8 . The method of claim 1 , wherein the adaptive port selection codebook configuration includes another field indicating configuration of the precoding matrix indicator when partial reciprocity operations are activated,
wherein the adaptive port selection codebook configuration includes another field indicating configuration of the precoding matrix indicator when partial reciprocity operations are deactivated.
9 . The method of claim 1 , wherein the configuration of the precoding matrix indicator indicates one or more portions of the precoding matrix indicator to drop or retain, depending on interpretation.
10 . The method of claim 1 , wherein the adaptive port selection codebook configuration includes an additional field pointing to a plurality of sounding reference signal resource sets or sounding reference signal trigger codepoints for the partial reciprocity operations.
11 . The method of claim 1 , further comprising:
activating or deactivating the interpretation of the adaptive port selection codebook configuration via dynamic downlink signaling.
12 . The method of claim 1 , wherein the dynamic downlink signaling includes downlink control information or media access control control element (MAC CE).
13 . A user equipment comprising:
at least one processor; and
at least one memory including computer program code; the at least one memory and the computer program code configured to, with the at least one processor, cause the user equipment at least to perform:
receiving at least one channel state information reporting configuration from a network node, the at least one channel state information reporting configuration including precoding matrix indicator as reporting quantity and an adaptive port selection codebook configuration for the precoding matrix indicator, wherein the adaptive port selection codebook configuration includes an additional field indicating a number of downlink reference signals, ports and resources to be used when partial reciprocity operations are activated or deactivated;
determining whether partial reciprocity operations for adaptive port selection precoding matrix indicator are activated, the determining based at least on information in a sounding reference signal request field of a downlink control information, an active semi-persistent sounding reference signal, or a periodic sounding reference signal configured by higher layers; and
determining a port selection precoding matrix indicator based at least on interpreting of the adaptive port selection codebook configuration that the partial reciprocity operations are activated, wherein the interpreting of the adaptive port selection codebook configuration for the precoding matrix indicator includes determining dimensions of a precoder in spatial and frequency domains, time offset between sounding reference signal transmission and downlink reference signal measurements, a number of downlink reference signals ports to be measured, a number of quantization bits, and a maximum number of non-zero coefficients,
the at least one memory and the computer program code further configured to, with the at least one processor, cause the user equipment at least to perform:
transmitting a sounding reference signal and the precoding matrix indicator, the precoding matrix indicator being determined based at least on interpreting of the adaptive port selection codebook configuration, to the network node,
wherein the sounding reference signal resource sets suitable for partial reciprocity-based port selection precoding matrix indicator reporting are determined based at least on a number of ports, a frequency domain density, and power level.
14 . The user equipment of claim 13 , wherein the at least one memory and the computer program code further configured to, with the at least one processor, cause the user equipment at least to perform:
activating or deactivating interpretation of the adaptive port selection codebook configuration based on dynamic downlink signaling comprising downlink control information (DCI) or a media access control control element (MAC CE).
15 . The user equipment of claim 13 , wherein when a sounding reference signal request triggers aperiodic sounding reference signal transmission with a resource set not included in an associated-SRS field of the adaptive port selection codebook configuration, the at least one memory and the computer program code are further configured to, with the at least one processor, cause the user equipment at least to perform:
determining that partial reciprocity operations are not active and assumes Rel-15 or Rel-16 port selection without partial reciprocity-based operations.
16 . The user equipment of claim 13 , wherein the adaptive port selection codebook configuration includes a first codebook configuration for non-SRS-assisted port selection and a second codebook configuration for SRS-assisted port selection, and wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the user equipment at least to perform:
generating a port selection report with one of the configurations depending on a codepoint in an SRS request field of downlink control information.
17 . The user equipment of claim 13 , wherein when partial reciprocity operations are activated, the at least one memory and the computer program code are further configured to, with the at least one processor, cause the user equipment at least to perform:
generating and transmitting a partial precoding matrix indicator report having reduced payload relative to a full precoding matrix indicator report.
18 . The user equipment of claim 13 , wherein the configuration of the precoding matrix indicator indicates one or more portions of the precoding matrix indicator to drop or retain, including at least a portion relating to channel wideband information.
19 . The user equipment of claim 13 , wherein when partial reciprocity operations are active, the at least one memory and the computer program code are further configured to, with the at least one processor, cause the user equipment at least to perform:
measuring configured channel state information reference signal resources assuming precoding based on wideband information from sounding reference signal measurements and active partial-reciprocity operations.