Determining channel state information in 5G or other next generation wireless communication systems with multiple transmission points
The described technology is generally directed towards indicating to a receiver (e.g., a user equipment) which antenna ports are assigned for channel state information reference signals (CSI-RS). The indicator can be sent as radio resource control configuration data and/or by physical layer signaling such as in downlink control information. The receiver computes CSI based on the assigned antenna port or ports, and the reported (e.g., joint) CSI helps avoid mismatched joint CSI used for scheduling when multiple transmit and receive points (TRPs) are communicating with the user equipment.
1. A first transmit and receive point device of a wireless network, comprising:
a processor; and
a memory that stores executable instructions that, when executed by the processor, facilitate performance of operations, the operations comprising:
assigning at least one first antenna port of the first transmit and receive point device for transmission of first channel state information reference signals to a user equipment;
receiving, from a second transmit and receive point device, information comprising at least one second antenna port of the second transmit and receive point device for transmission of second channel state information reference signals to the user equipment;
sending, to the user equipment, indicator data comprising a combined indication that the at least one first antenna port and the at least one second antenna port are assigned for transmission of the first channel state information reference signals and the second channel state information reference signals to the user equipment; and
transmitting the first channel state information reference signals to the user equipment via the at least one first antenna port.
2. The first transmit and receive point device of claim 1 , wherein the receiving, from the second transmit and receive point device, occurs via a backhaul communication link.
3. The first transmit and receive point device of claim 1 , wherein the second transmit and receive point device is collocated with the first transmit and receive point device.
4. The first transmit and receive point device of claim 1 , wherein the operations further comprise receiving joint channel state information from the user equipment based on the first channel state information reference signals transmitted via the at least one first antenna port.
5. The first transmit and receive point device of claim 1 , wherein sending the indicator data to the user equipment comprises sending the indicator data in a radio resource control configuration message.
6. The first transmit and receive point device of claim 1 , wherein sending the indicator data to the user equipment comprises sending the indicator data using physical layer signaling.
7. The first transmit and receive point device of claim 1 , wherein sending the indicator data to the user equipment comprises sending the indicator data in downlink control information.
8. The first transmit and receive point device of claim 1 , wherein sending the indicator data to the user equipment comprises sending an index value to a data structure that maps the index value to a group of channel state information reference signal ports.
9. The first transmit and receive point device of claim 1 , wherein sending the indicator data to the user equipment comprises sending bitmap data to the user equipment, the bitmap data comprising respective bit values that indicate whether respective ports of the first transmit and receive point device and the second transmit and receive point device are assigned for transmission of respective channel state information reference signals.
10. Network equipment, comprising:
a processor; and
a memory that stores executable instructions that, when executed by the processor, facilitate performance of operations, the operations comprising:
receiving indicator data from a first transmit and receive point device, the indicator data comprising a combined indication of at least one first antenna port of the first transmit and receive point device for transmission of first channel state information reference signals to the network equipment and at least one second antenna port of a second transmit and receive point device for transmission of second channel state information reference signals to the network equipment;
receiving the first channel state information reference signals and the second channel state information reference signals;
determining port information from the indicator data, wherein the port information indicates on which antenna ports of the at least one first antenna port and the at least one second antenna port, that the first channel state information reference signals and the second channel state information reference signals were transmitted for reception by the network equipment;
using the port information and the first channel state information reference signals and the second channel state information reference signals to determine joint channel state information; and
reporting the joint channel state information to the first transmit and receive point device.
11. The network equipment of claim 10 , wherein receiving the indicator data comprises receiving a radio resource control configuration message.
12. The network equipment of claim 10 , wherein receiving the indicator data comprises receiving downlink control information.
13. The network equipment of claim 10 , wherein determining the port information comprises accessing a data structure that associates the indicator data with port identifiers.
14. A non-transitory machine-readable medium, comprising executable instructions that, when executed by a processor of a first transmit and receive point device, facilitate performance of operations, the operations comprising:
determining a first group comprising a first antenna port for transmission of first channel state information reference signals to a user equipment;
communicating with a second transmit and receive point device to determine a second group comprising a second antenna port, which is not in the first group, for transmission of second channel state information reference signals to the user equipment; and
sending indicator data to the user equipment comprising a combined indication that a combination of the first group and the second group are to be transmitting the first channel state information reference signals and the second channel state information reference signals to the user equipment.
15. The non-transitory machine-readable medium of claim 14 , wherein sending the indicator data comprises sending the indicator data in a radio resource control configuration message to the user equipment.
16. The non-transitory machine-readable medium of claim 14 , wherein sending the indicator data comprises sending the indicator data to the user equipment using physical layer signaling.
17. The non-transitory machine-readable medium of claim 14 , wherein sending the indicator data comprises sending a bitmap with respective bits in the bitmap representing respective ports of the first transmit and receive point device and the second transmit and receive point device, and comprising respective bit values indicating whether a respective port is to be used or is not to be used for transmission of channel state information reference signals to the user equipment.
18. The non-transitory machine-readable medium of claim 14 , wherein sending the indicator data comprises sending an index value to a data structure that maps respective index values to respective antenna port identifiers.
19. The non-transitory machine-readable medium of claim 14 , wherein the operations further comprise sending the first channel state information reference signals to the user equipment via the first antenna port.
20. The non-transitory machine-readable medium of claim 19 , wherein the operations further comprise receiving joint channel state information responsive to sending the first channel state information reference signals.