Method and apparatus for channel state information reference signal (CSI-RS)
Methods and apparatuses for CSI reporting mechanisms are provided. A user equipment (UE) includes a transceiver and a processor operably connected to the transceiver. The transceiver is configured to receive information indicating a channel state information reference signal (CSI-RS) resource configuration, uplink-related downlink control information (DCI), and a CSI-RS associated with a selected CSI-RS resource in a same subframe as the uplink-related DCI. The processor configured to determine, in response to a CSI request included in the uplink-related DCI, an aperiodic CSI in reference to the CSI-RS. The transceiver is further configured to report the aperiodic CSI by transmitting the aperiodic CSI on an uplink channel.
1. A user equipment (UE) comprising:
a transceiver configured to receive information indicating a channel state information reference signal (CSI-RS) resource configuration, an activation message for a CSI-RS, and the CSI-RS that is associated with a selected CSI-RS resource; and
a processor operably connected to the transceiver, the processor configured to calculate CSI in reference to the CSI-RS,
wherein the transceiver is further configured to report the CSI by transmitting the CSI on an uplink channel,
wherein the activation message indicates a starting transmission time interval of the CSI-RS,
wherein the information indicating the CSI-RS resource configuration is received via higher-layer signaling, and
wherein the CSI-RS resource configuration includes a periodicity and an offset.
2. The UE of claim 1 , wherein the activation message is received via a medium access control (MAC) control element (CE).
3. The UE of claim 2 , wherein a deactivation message indicating an ending transmission time interval of the CSI-RS is received via the MAC CE.
4. The UE of claim 1 , wherein the activation message is included in downlink control information (DCI) and received via a physical downlink control channel (PDCCH).
5. The UE of claim 4 , wherein a deactivation message indicating an ending transmission time interval of the CSI-RS is included in the DCI and received via the PDCCH.
6. A base station (BS) comprising:
a processor configured to generate information indicating a channel state information reference signal (CSI-RS) resource configuration and an activation message for a CSI-RS; and
a transceiver operably connected to the processor, the transceiver configured to:
transmit the information indicating the CSI-RS resource configuration, the activation message for the CSI-RS, and the CSI-RS that is associated with a selected CSI-RS resource, and
receive CSI calculated in reference to the CSI-RS reported on an uplink channel,
wherein the activation message indicates a starting transmission time interval of the CSI-RS,
wherein the information indicating the CSI-RS resource configuration is transmitted via higher-layer signaling, and
wherein the CSI-RS resource configuration includes a periodicity and an offset.
7. The BS of claim 6 , wherein the activation message is transmitted via a medium access control (MAC) control element (CE).
8. The BS of claim 7 , wherein a deactivation message indicating an ending transmission time interval of the CSI-RS is transmitted via the MAC CE.
9. The BS of claim 6 , wherein the activation message is included in downlink control information (DCI) and transmitted via a physical downlink control channel (PDCCH).
10. The BS of claim 9 , wherein a deactivation message indicating an ending transmission time interval of the CSI-RS is included in the DCI and transmitted via the PDCCH.
11. A method for operating a user equipment (UE), the method comprising:
receiving information indicating a channel state information reference signal (CSI-RS) resource configuration, an activation message for a CSI-RS, and the CSI-RS that is associated with a selected CSI-RS resource;
calculating CSI in reference to the CSI-RS; and
reporting the CSI by transmitting the CSI on an uplink channel,
wherein the activation message indicates a starting transmission time interval of the CSI-RS,
wherein the information indicating the CSI-RS resource configuration is received via higher-layer signaling, and
wherein the CSI-RS resource configuration includes a periodicity and an offset.
12. The method of claim 11 , wherein the activation message is received via a medium access control (MAC) control element (CE).
13. The method of claim 12 , wherein a deactivation message indicating an ending transmission time interval of the CSI-RS is received via the MAC CE.
14. The method of claim 11 , wherein the activation message is included in downlink control information (DCI) and received via a physical downlink control channel (PDCCH).
15. The method of claim 14 , wherein a deactivation message indicating an ending transmission time interval of the CSI-RS is included in the DCI and received via the PDCCH.