Apparatuses, methods, computer programs and computer program products for beam indication
In some embodiments, a network (e.g., a TRP) provides to a UE information indicating that a transmitted “first” RS resource (or “RS” for short) is quasi-co-located (QCL) with a scheduled transmission for the UE (e.g., a “second” RS). The UE may then receive the scheduled transmission under an assumption that the scheduled transmission (e.g., a second RS, such as a demodulation RS (DMRS)) is QCL with the first RS. The UE may receive such QCL information before, after or while receiving the first RS.
1. A method implemented in a wireless device, comprising:
receiving a first reference signal (RS);
before or after or while receiving the first RS, further receiving information indicating that the first RS is quasi-co-located (QCL) with a scheduled transmission, wherein the information comprises a quasi-co-location indicator (QRI) representing a QRI state selected from a set of available QRI states, wherein one or more of the available QRIs states is i) associated with an RS type and ii) associated with an RS index (RSI) identifying a transmission of an RS of the RS type with which the QRI state is associated; and
receiving the scheduled transmission under an assumption that the scheduled transmission is QCL with the first RS, wherein
the set of available QRI states comprises a first QRI state and a second QRI state,
the first QRI state is associated with a first type of RS,
the second QRI state is associated with a second type of RS, and
the first and second types of RS are two different types of RS from among the following three types of RS:
synchronization signal block (SSB),
periodic channel state information RS (CSI-RS), and
aperiodic CSI-RS.
2. The method of claim 1 , wherein the first type of RS is SSB or periodic CSI-RS and the second type of RS is aperiodic CSI-RS.
3. The method of claim 1 , wherein the first type of RS is associated with more robust beams than the second type of RS.
4. The method of claim 1 , wherein said information indicates that the first RS is spatially QCL with the scheduled transmission, and wherein the scheduled transmission is received under an assumption that the scheduled transmission is spatially QCL with the first RS.
5. A wireless device, the wireless device comprising:
a receiver; and
a processor configured to control the receiver, wherein the wireless device is configured to:
receive a first reference signal (RS);
before or after or while receiving the first RS, further receiving information indicating that the first RS is quasi-co-located (QCL) with a scheduled transmission, wherein the information comprises a quasi-co-location indicator (QRI) representing a QRI state selected from a set of available QRI states, wherein one or more of the QRIs states is i) associated with an RS type and ii) associated with an RS index (RSI) identifying a transmission of an RS of the RS type with which the QRI state is associated; and
receive the scheduled transmission under an assumption that the scheduled transmission is QCL with the first RS, wherein
the set of available QRI states comprises a first QRI state and a second QRI state,
the first QRI state is associated with a first type of RS,
the second QRI state is associated with a second type of RS, and
the first and second types of RS are two different types of RS from among the following three types of RS:
synchronization signal block (SSB),
periodic channel state information RS (CSI-RS), and
aperiodic CSI-RS.
6. The wireless device of claim 5 , wherein the first type of RS is SSB or periodic CSI-RS and the second type of RS is aperiodic CSI-RS.
7. The wireless device of claim 5 , wherein the first type of RS is associated with more robust beams than the second type of RS.
8. The wireless device of claim 5 , wherein said information indicates that the first RS is spatially QCL with the scheduled transmission, and wherein the scheduled transmission is received under an assumption that the scheduled transmission is spatially QCL with the first RS.