Configuration of demodulation reference signals in beamformed wireless communication systems
Various embodiments disclosed herein provide for efficient configuration of demodulation reference signals in beamformed wireless communications systems. In an embodiment, the transmitter can signal the location of demodulation reference signals (DMRS) by including an indicator bit in downlink control information indicating which DMRS scheme is used in the transmission. A first DMRS scheme can let the user equipment (UE) device know that the DMRS position for the PDSCH carrying the RMSI is as signaled on the master information block (MIB)—referred to as PDSCH Mapping Type A. A second DMRS scheme can let the UE device know that the DMRS position for the PDSCH carrying the RMSI is the first orthogonal frequency division multiplexing (OFDM) symbol of said PDSCH allocation—referred to as PDSCH mapping type B).
1. A base station device, comprising:
a processor; and
a memory that stores executable instructions that, when executed by the processor, facilitate performance of operations, comprising:
signaling a location for a demodulation reference signal in a data transport data channel, wherein the location identifies a symbol of the data transport data channel in which the demodulation reference signal is located, and wherein the data transport data channel transports data comprising remaining system information, wherein the remaining system information is system information that is not transmitted via a control channel, and wherein the signaling the location further comprises:
selecting a first table of a group of tables, wherein a first symbol index column of the first table indicates the location of the demodulation reference signal in the data transport data channel;
multiplexing the data transport data channel with a synchronization block that comprises a synchronization signal and a physical broadcast channel for a spatial direction; and
transmitting a beam comprising the data transport data channel and the synchronization block in the spatial direction, wherein the beam comprises a beam-formed transmission.
2. The base station device of claim 1 , wherein the signaling the location comprises:
setting an indicator bit in downlink control information associated with a control channel that schedules the data transport data channel, wherein the indicator bit indicates the location for the demodulation reference signal.
3. The base station device of claim 2 , wherein a first setting of the indicator bit indicates that a master information block in the physical broadcast channel identifies the location of the demodulation reference signal.
4. The base station device of claim 2 , wherein a second setting of the indicator bit indicates that a first symbol of the data transport data channel comprises the demodulation reference signal.
5. The base station device of claim 1 , wherein the signaling the location further comprises:
identifying a resource allocation for the data transport data channel in downlink control information, wherein the demodulation reference signal is located at the resource allocation.
6. The base station device of claim 5 , wherein the identifying is based on matching a number of bits in the downlink control information to a row in a second table of resource allocation locations.
7. The base station device of claim 1 , wherein the signaling the location further comprises:
signaling the location in a master information block in the physical broadcast channel that identifies the location of the demodulation reference signal.
8. The base station device of claim 7 , wherein the location is based on a time index of the synchronization block associated with the physical broadcast channel.
9. The base station device of claim 1 , wherein the location of the demodulation reference signal is based on a carrier frequency of the beam.
10. The base station device of claim 1 , wherein the location of the demodulation reference signal is based on a number of antennas of the base station device.
11. A method, comprising:
identifying, by a transmitter device comprising a processor, a location for a demodulation reference signal in a data transport data channel, wherein the location identifies a symbol of the data transport data channel in which the demodulation reference signal is located, and wherein the data transport data channel is used to transmit data comprising system information, and wherein the identifying comprises:
indicating a selection of a table of a group of tables, wherein a first symbol index column of the table indicates the location of the demodulation reference signal in the data transport data channel;
combining, by the transmitter device, the data transport data channel with a synchronization signal block that comprises a synchronization signal and a physical broadcast channel, wherein the combining is performed via orthogonal frequency division multiplexing; and
transmitting, by the transmitter device, a beam comprising the data transport data channel and the synchronization signal block, wherein the beam comprises a beam-formed transmission.
12. The method of claim 11 , further comprising:
setting, by the transmitter device, an indicator bit in downlink control information in a control channel that schedules the data transport data channel, wherein the indicator bit is associated with the location for the demodulation reference signal.
13. The method of claim 12 , wherein a first setting of the indicator bit indicates that a master information block in the physical broadcast channel identifies the location of the demodulation reference signal.
14. The method of claim 12 , wherein a second setting of the indicator bit indicates that a first symbol of the data transport data channel comprises the demodulation reference signal.
15. The method of claim 11 , wherein the identifying further comprises:
indicating a resource allocation for the data transport data channel in downlink control information, wherein the demodulation reference signal is located at the resource allocation.
16. The method of claim 11 , wherein the location is based on a time index of the synchronization signal block associated with the physical broadcast channel.
17. A non-transitory machine-readable storage medium, comprising executable instructions that, when executed by a processor of a device, facilitate performance of operations, comprising:
identifying a location for a demodulation reference signal in a physical downlink shared channel, wherein the location identifies a symbol of the physical downlink shared channel in which the demodulation reference signal is located, and wherein the physical downlink shared channel facilitates transmission of data comprising remaining system information, and wherein remaining system information is information left over after a control channel transmission, and wherein the identifying comprises:
indicating a selection of a table of a group of tables, wherein a first symbol index column of the table indicates the location of the demodulation reference signal in the physical downlink shared channel;
combining the physical downlink shared channel with a synchronization signal block that comprises a synchronization signal and a physical broadcast channel, wherein the combining is performed via orthogonal frequency division multiplexing; and
transmitting a beam comprising the physical downlink shared channel and the synchronization signal block, wherein the beam comprises a beam-formed transmission.
18. The non-transitory machine-readable storage medium of claim 17 , wherein the operations further comprise:
setting an indicator bit in downlink control information in a control channel that schedules the physical downlink shared channel, wherein the indicator bit is associated with the location for the demodulation reference signal, wherein a first setting of the indicator bit indicates that a master information block in the physical broadcast channel identifies the location of the demodulation reference signal and wherein a second setting of the indicator bit indicates that a first symbol of the physical downlink shared channel comprises the demodulation reference signal.
19. The non-transitory machine-readable storage medium of claim 17 , wherein the identifying further comprises:
indicating a resource allocation for the physical downlink shared channel in downlink control information, wherein the demodulation reference signal is located at the resource allocation.
20. The non-transitory machine-readable storage medium of claim 17 , wherein the location is based on a time index of the synchronization signal block associated with the physical broadcast channel.