Code-division multiplexing (CDM) groups for multi-source transmission
Embodiments include methods, performed by a user equipment (UE), for transmitting or receiving a plurality of physical data channels in a wireless network. Such methods include receiving, from the wireless network, an indication of a Transmission Configuration Indicator (TCI) state that includes one or more source reference signal (RS) pairs. Each source RS pair has a pair of quasi-colocation (QCL) relations with antenna ports, for demodulation reference signals (DM-RS), that are mapped to a plurality of code-division multiplexing (CDM) groups. Such methods include receiving/transmitting the physical data channels based on the QCL relations for the source RS pairs of the indicated TCI state. Each physical data channel corresponds to a CDM group and is received/transmitted in association with the DM-RS having antenna ports mapped to the corresponding CDM group. Other embodiments include complementary methods performed by a wireless network, and UEs and wireless networks configured to perform such methods.
1. A method for a user equipment (UE) to transmit or receive a plurality of physical data channels in a wireless network, the method comprising:
receiving, from the wireless network, an indication of a Transmission Configuration Indicator (TCI) state that includes the following:
a plurality of source reference signal (RS) pairs, each source RS pair comprising first and second source RS; and
for each source RS pair, a corresponding pair of quasi-colocation (QCL) relations between the first and second source RS and a single code-division multiplexing (CDM) group of demodulation reference signal (DM-RS) antenna ports,
wherein each source RS pair has a corresponding pair of QCL relations with a different CDM group than all other source RS pairs of the plurality; and
receiving or transmitting the plurality of physical data channels based on the QCL relations for the plurality of source RS pairs of the indicated TCI state.
2. The method of claim 1 , further comprising receiving, from the wireless network, an indication of a plurality of the antenna ports for DM-RS, wherein each antenna port is mapped to a CDM group associated with one of the physical data channels.
3. The method of claim 1 , wherein each physical data channel is associated with a corresponding CDM group and is received or transmitted in association with the plurality of DM-RS having antenna ports mapped to the corresponding CDM group.
4. The method of claim 1 , wherein one of the following applies:
the plurality of physical data channels are respective layers of a physical downlink shared channel (PDSCH);
the plurality of physical data channels are respective layers of a physical uplink shared channel (PUSCH);
each physical data channel is a subset of all layers of a PDSCH; or
each physical data channel is a subset of all layers of a PUSCH.
5. The method of claim 1 , wherein the indicated TCI state includes:
a first source RS pair having a corresponding first pair of QCL relations with all antenna ports associated with a first CDM group; and
a second source RS pair having a corresponding second pair of QCL relations with all antenna ports associated with a second CDM group.
6. The method of claim 5 , wherein the number of antenna ports associated with the first CDM group is different than the number of antenna ports associated with the second CDM group.
7. The method of claim 5 , wherein:
the indicated TCI state also includes a third source RS pair having a corresponding third pair of QCL relations with all antenna ports associated with a third CDM group; and
the first, second, and third CDM groups are associated with respective first, second, and third sources in the wireless network.
8. The method of claim 5 , wherein the indicated TCI state identifies a first TCI state including the first source RS pair and a second TCI state including the second source RS pair.
9. The method of claim 5 , wherein:
the first and second CDM groups are associated with respective first and second indices; and
the first index is less than the second index.
10. The method of claim 9 , further comprising receiving, from the wireless network, scheduling information for the physical data channels, wherein the scheduling information includes the first and second indices associated with the respective first and second CDM groups.
11. The method of claim 1 , wherein:
the indicated TCI state is one of a symmetric pair of TCI states;
each TCI state of the symmetric pair includes first and second source RS pairs; and
each TCI state of the symmetric pair has different QCL relations between the first and second source RS pairs and antenna ports that are mapped to first and second CDM groups.
12. The method of claim 1 , wherein one of the following applies:
the DM-RS are Type-1 and the TCI state includes no more than two source RS pairs; or
the DM-RS are Type-2 and the TCI state includes no more than three source RS pairs.
13. The method of claim 1 , further comprising:
receiving, from the wireless network, an indication of a plurality of TCI states, each TCI state including a plurality of source RS pairs, each source RS pair comprising first and second source RS; and
for each of the plurality of TCI states, determining channel parameters based on receiving the source RS of the plurality of source RS pairs associated with the TCI state.
14. The method of claim 13 , wherein the TCI state indicated by the configuration information is one of the plurality of TCI states.
15. The method of claim 13 , wherein receiving the plurality of physical data channels based on the QCL relations comprises, for each of the physical data channels:
selecting a subset of the determined channel parameters based on the QCL relations associated with the CDM group corresponding to the physical data channel;
receiving the DM-RS mapped to the corresponding CDM group based on the subset of channel parameters;
determining further channel parameters based on the received DM-RS; and
receiving the physical data channel based on the further channel parameters.
16. A method for by a wireless network to transmit or receive a plurality of physical data channels with a single user equipment (UE), the method comprising:
transmitting, to the UE, an indication of a Transmission Configuration Indicator (TCI) state that includes the following:
a plurality of source reference signal (RS) pairs, each source RS pair comprising first and second source RS; and
for each source RS pair, a corresponding pair of quasi-colocation (QCL) relations between the first and second source RS and a single code-division multiplexing (CDM) group of demodulation reference signal (DM-RS) antenna ports,
wherein each source RS pair has a corresponding pair of QCL relations with a different CDM group than all other source RS pairs of the plurality; and
transmitting the plurality of physical data channels to, or receiving the plurality of physical data channels from, the UE based on the QCL relations for the plurality of source RS pairs of the indicated TCI state.
17. The method of claim 16 , further comprising transmitting, to the UE, an indication of a plurality of the antenna ports for DM-RS, wherein each antenna port is mapped to a CDM group associated with one of the physical data channels.
18. The method of claim 16 , wherein each physical data channel is associated with a corresponding CDM group and is transmitted or received in association with the plurality of DM-RS having antenna ports mapped to the corresponding CDM group.
19. The method of claim 16 , wherein one of the following applies:
the plurality of physical data channels are respective layers of a physical downlink shared channel (PDSCH);
the plurality of physical data channels are respective layers of a physical uplink shared channel (PUSCH);
each physical data channel is a subset of all layers of a PDSCH; or
each physical data channel is a subset of all layers of a PUSCH.
20. The method of claim 16 , wherein the indicated TCI state includes:
a first source RS pair having a corresponding first pair of QCL relations with all antenna ports associated with a first CDM group; and
a second source RS pair having a corresponding second pair of QCL relations with all antenna ports associated with a second CDM group.
21. The method of claim 20 , wherein the number of antenna ports associated with the first CDM group is different than the number of antenna ports associated with the second CDM group.
22. The method of claim 20 , wherein:
the indicated TCI state also includes a third source RS pair having a corresponding third pair of QCL relations with all antenna ports associated with a third CDM group; and
the first, second, and third CDM groups are associated with respective first second and third sources.
23. The method of claim 20 , wherein the indicated TCI state identifies a first TCI state including the first source RS pair and a second TCI state including the second source RS pair.
24. The method of claim 20 , wherein:
the first and second CDM groups are associated with respective first and second indices; and
the first index is less than the second index.
25. The method of claim 24 , further comprising transmitting, to the UE, scheduling information for the physical data channels, wherein the scheduling information includes the first and second indices associated with the respective first and second CDM groups.
26. The method of claim 16 , wherein:
the indicated TCI state is one of a symmetric pair of TCI states;
each TCI state of the symmetric pair includes first and second source RS pairs; and
each TCI state of the symmetric pair has different QCL relations between the first and second source RS pairs and antenna ports that are mapped to first and second CDM groups.
27. The method of claim 16 , wherein one of the following applies:
the DM-RS are Type-1, and the TCI state includes no more than two source RS pairs; or
the DM-RS are Type-2, and the TCI state includes no more than three source RS pairs.
28. The method of claim 16 , further comprising transmitting, to the UE, an indication of a plurality of TCI states, each TCI state including a plurality of source RS pairs, each source RS pair comprising first and second source RS, wherein the TCI state indicated by the configuration information is one of the plurality of TCI states.
29. A user equipment (UE) configured to transmit or receive a plurality of physical data channels in a wireless network, the UE comprising:
radio transceiver circuitry configured to communicate with a plurality of nodes in the wireless network; and
processing circuitry operatively coupled to the radio transceiver circuitry, whereby the processing circuitry and the radio transceiver circuitry are configured to perform the method of claim 1 .
30. A non-transitory, computer-readable medium storing computer-executable instructions that, when executed by processing circuitry of a user equipment (UE) configured to transmit or receive a plurality of physical data channels in a wireless network, configure the UE to perform the method of claim 1 .
31. A wireless network comprising one or more nodes, the wireless network being configured to transmit or receive a plurality of physical data channels with a single user equipment (UE), the one or more nodes comprising:
radio network interface circuitry configured to communicate with the UE; and
processing circuitry operatively coupled to the radio network interface circuitry, whereby the processing circuitry and the radio network interface circuitry are configured to perform the method of claim 16 .
32. A non-transitory, computer-readable medium storing computer-executable instructions that, when executed by processing circuitry of one or more nodes a wireless network configured to transmit or receive a plurality of physical data channels with a single user equipment (UE), configure the one or more nodes to perform the method of claim 16 .