Method for a UE for requesting a channel state information reference signal (CSI-RS) or a sounding reference signal (SRS)
Aspects of the disclosure relate to a method of operating a scheduled entity for wireless communication with a network. In some aspects, the scheduled entity transmits a message that requests a scheduling entity to transmit at least one reference signal. The scheduled entity obtains channel state information based on the at least one reference signal. The scheduled entity transmits a report that includes the channel state information. In other aspects, the scheduled entity transmits a message that requests a scheduling entity to schedule a reference signal transmission for the scheduled entity. The scheduled entity obtains an assignment of resources for transmission of the reference signal in response to the message. The scheduled entity transmits the reference signal based on the assignment of resources. Other aspects, embodiments, and features are also claimed and described.
1. A method of wireless communication, comprising:
transmitting, from a scheduled entity, a message that requests a scheduling entity to transmit at least one reference signal, the message including one or more spatial quasi co-location (QCL) indications, wherein the at least one reference signal enables measurement of a channel;
receiving the at least one reference signal using one or more reception directivity patterns, at least one of the one or more reception directivity patterns being compatible with at least one of the one or more spatial QCL indications;
obtaining, at the scheduled entity, channel state information based on the at least one reference signal; and
transmitting, from the scheduled entity, a report that includes the channel state information.
2. The method of claim 1 , wherein obtaining the channel state information based on the at least one reference signal comprises:
obtaining one or more measurements for the channel using the at least one reference signal; and
determining the channel state information based on the one or more measurements.
3. The method of claim 1 , wherein the at least one reference signal is a channel state information reference signal (CSI-RS).
4. The method of claim 1 , wherein the scheduled entity transmits the message if the scheduled entity has refined a reception beam for at least one beam pair link, if the scheduled entity has switched a reception subarray for at least one beam pair link, or if the scheduled entity has detected a change of the channel of at least one beam pair link, and wherein the at least one beam pair link is configured for downlink traffic.
5. The method of claim 1 , further comprising:
estimating an amount of improvement in a quality of a downlink data transmission to be gained from the transmission of the reference signal, wherein the estimated amount of improvement is included in the message.
6. The method of claim 1 , wherein the message includes a downlink beam report, and wherein a request for transmission of the at least one reference signal is included in the downlink beam report.
7. An apparatus for wireless communication, comprising:
at least one processor;
a transceiver communicatively coupled to the at least one processor; and
a memory communicatively coupled to the at least one processor,
wherein the at least one processor is configured to:
transmit a message that requests a scheduling entity to transmit at least one reference signal, the message including one or more spatial quasi co-location (QCL) indications, wherein the at least one reference signal enables measurement of a channel;
receive the at least one reference signal using one or more reception directivity patterns, at least one of the one or more reception directivity patterns being compatible with at least one of the one or more spatial QCL indications;
obtain channel state information based on the at least one reference signal; and
transmit a report that includes the channel state information.
8. An apparatus for wireless communication, comprising:
means for transmitting a message that requests a scheduling entity to transmit at least one reference signal, the message including one or more spatial quasi co-location (QCL) indications, wherein the at least one reference signal enables measurement of a channel;
means for receiving the at least one reference signal using one or more reception directivity patterns, at least one of the one or more reception directivity patterns being compatible with at least one of the one or more spatial QCL indications;
means for obtaining channel state information based on the at least one reference signal; and
means for transmitting a report that includes the channel state information.
9. A non-transitory computer-readable medium storing computer-executable code, comprising code for causing a computer to:
transmit, from a scheduled entity, a message that requests a scheduling entity to transmit at least one reference signal, the message including one or more spatial quasi co-location (QCL) indications, wherein the at least one reference signal enables measurement of a channel;
receive the at least one reference signal using one or more reception directivity patterns, at least one of the one or more reception directivity patterns being compatible with at least one of the one or more spatial QCL indications;
obtain, at the scheduled entity, channel state information based on the at least one reference signal; and
transmit, from the scheduled entity, a report that includes the channel state information.
10. A method of wireless communication, comprising:
obtaining, at a scheduling entity, a message that requests the scheduling entity to transmit at least one reference signal, the message including one or more spatial quasi co-location (QCL) indications, wherein the at least one reference signal enables measurement of a channel; and
transmitting, from the scheduling entity, the at least one reference signal to a scheduled entity in response to the message, wherein the at least one reference signal is transmitted using one or more transmission directivity patterns, at least one of the one or more transmission directivity patterns being compatible with at least one of the one or more spatial QCL indications.
11. The method of claim 10 , further comprising:
obtaining, at the scheduling entity, a report including channel state information from the scheduled entity, wherein the channel state information is based on the at least one reference signal; and
transmitting, from the scheduling entity, data based on at least the channel state information.
12. The method of claim 10 , wherein the at least one reference signal is a channel state information reference signal (CSI-RS).
13. The method of claim 11 , wherein the data is transmitted in a multiple-input multiple-output (MIMO) transmission mode using a modulation and coding scheme (MCS) that is determined using the channel state information.
14. An apparatus for wireless communication, comprising:
at least one processor;
a transceiver communicatively coupled to the at least one processor; and
a memory communicatively coupled to the at least one processor,
wherein the at least one processor is configured to:
obtain a message that requests the scheduling entity to transmit at least one reference signal, the message including one or more spatial quasi co-location (QCL) indications, wherein the at least one reference signal enables measurement of a channel; and
transmit the at least one reference signal to a scheduled entity in response to the message, wherein the at least one reference signal is transmitted using one or more transmission directivity patterns, at least one of the one or more transmission directivity patterns being compatible with at least one of the one or more spatial QCL indications.
15. An apparatus for wireless communication, comprising:
means for obtaining a message that requests the scheduling entity to transmit at least one reference signal, the message including one or more spatial quasi co-location (QCL) indications, wherein the at least one reference signal enables measurement of a channel; and
means for transmitting the at least one reference signal to a scheduled entity in response to the message, wherein the at least one reference signal is transmitted using one or more transmission directivity patterns, at least one of the one or more transmission directivity patterns being compatible with at least one of the one or more spatial QCL indications.
16. A non-transitory computer-readable medium storing computer-executable code, comprising code for causing a computer to:
obtain, at a scheduling entity, a message that requests the scheduling entity to transmit at least one reference signal, the message including one or more spatial quasi co-location (QCL) indications, wherein the at least one reference signal enables measurement of a channel; and
transmit, from the scheduling entity, the at least one reference signal to a scheduled entity in response to the message, wherein the at least one reference signal is transmitted using one or more transmission directivity patterns, at least one of the one or more transmission directivity patterns being compatible with at least one of the one or more spatial QCL indications.