Terminal device, network device and methods therein
A method in a terminal device. The method includes determining a DeModulation Reference Signal (DMRS) configuration for a Physical Uplink Shared Channel (PUSCH) and transmitting to a network device the PUSCH using the DMRS configuration along with a preamble, in a random access message.
1. A method in a terminal device, comprising:
determining a DeModulation Reference Signal (DMRS) configuration for a Physical Uplink Shared Channel (PUSCH), wherein the DMRS configuration comprises a DMRS sequence and the determining the DMRS configuration comprises generating the DMRS sequence by using an identifier of a preamble as an initialization parameter; and
transmitting to a network device the PUSCH using the DMRS configuration along with the preamble, in a random access message, wherein the random access message is a message A in a two-step random access procedure.
2. The method of claim 1 , wherein said determining the DMRS configuration is based on one or more of:
a frequency hopping configuration,
a PUSCH mapping type,
a PUSCH duration,
a number of symbols for DMRS,
a maximum number of additional DMRS symbols, or
a Code Division Multiplexing (CDM) group type.
3. The method of claim 1 , wherein the DMRS configuration comprises a time domain resource for DMRS, and said determining the DMRS configuration comprises determining the time domain resource for the DMRS based on one or more of:
a frequency hopping configuration,
a PUSCH mapping type,
a PUSCH duration,
a number of symbols for the DMRS,
a maximum number of additional DMRS symbols, or
a Code Division Multiplexing (CDM) group type.
4. The method of claim 2 , wherein the one or more of the frequency hopping configuration, the PUSCH mapping type, the PUSCH duration, the number of symbols for the DMRS, the maximum number of additional DMRS symbols or the CDM group type are predetermined by default or determined based on a sequence for the preamble.
5. The method of claim 2 , wherein the one or more of the frequency hopping configuration, the PUSCH mapping type, the PUSCH duration, the number of symbols for the DMRS, the maximum number of additional DMRS symbols or the CDM group type are received from the network device via signaling.
6. The method of claim 5 , wherein the signaling comprises Radio Resource Control (RRC) signaling or Layer 1 signaling, the RRC signaling comprising a system information message, a dedicated signaling message, or both the system information message and the dedicated signaling message, and the Layer 1 signaling comprising Downlink Control Information (DCI).
7. The method of claim 2 , wherein the maximum number of additional DMRS symbols is determined based on a moving speed of the terminal device.
8. The method of claim 3 , wherein the time domain resource for the DMRS is determined based on a predetermined mapping between the time domain resource for the DMRS and the one or more of the frequency hopping configuration, the PUSCH mapping type, the PUSCH duration, the number of symbols for the DMRS, the maximum number of additional DMRS symbols or the CDM group type.
9. The method of claim 1 , wherein the preamble is selected from a set of preambles reserved for two-step random access only.
10. A terminal device, comprising:
a processor; and
a memory, the memory comprising instructions which, when executed by the processor, cause the terminal device to:
determine a DeModulation Reference Signal (DMRS) configuration for a Physical Uplink Shared Channel (PUSCH), wherein the DMRS configuration comprises a DMRS sequence and to determine the DMRS configuration comprises to generate the DMRS sequence by using an identifier of a preamble as an initialization parameter; and
transmit to a network device the PUSCH using the DMRS configuration along with the preamble, in a random access message, wherein the random access message is a message A in a two-step random access procedure.
11. A method in a network device, comprising:
detecting a preamble from a terminal device, as a part of a random access message, the random access message further comprising a Physical Uplink Shared Channel (PUSCH) wherein the random access message is a message A in a two-step random access procedure; and
determining a DeModulation Reference Signal (DMRS) configuration for the PUSCH, wherein the DMRS configuration comprises a DMRS sequence, in which the DMRS sequence is generated by using an identifier of the preamble as an initialization parameter.
12. The method of claim 11 , wherein said determining the DMRS configuration is based on one or more of:
a frequency hopping configuration,
a PUSCH mapping type,
a PUSCH duration,
a number of symbols for the DMRS,
a maximum number of additional DMRS symbols, or
a Code Division Multiplexing (CDM) group type.
13. The method of claim 11 , wherein the DMRS configuration comprises a time domain resource for DMRS, and said determining the DMRS configuration comprises determining the time domain resource for DMRS based on one or more of:
a frequency hopping configuration,
a PUSCH mapping type,
a PUSCH duration,
a number of symbols for the DMRS,
a maximum number of additional DMRS symbols, or
a Code Division Multiplexing (CDM) group type.
14. The method of claim 12 , wherein the one or more of the frequency hopping configuration, the PUSCH mapping type, the PUSCH duration, the number of symbols for the DMRS, the maximum number of additional DMRS symbols or the CDM group type are predetermined by default or determined based on a sequence.
15. The method of claim 12 , further comprising:
transmitting the one or more of the frequency hopping configuration, the PUSCH mapping type, the PUSCH duration, the number of symbols for the DMRS, the maximum number of additional DMRS symbols or the CDM group type to the terminal device via signaling.
16. The method of claim 15 , wherein the signaling comprises Radio Resource Control (RRC) signaling or Layer 1 signaling, the RRC signaling comprising a system information message, a dedicated signaling message, or both the system information message and the dedicated signaling message, and the Layer 1 signaling comprising Downlink Control Information (DCI).
17. The method of claim 13 , wherein the time domain resource for the DMRS is determined based on a predetermined mapping between the time domain resource for the DMRS and the one or more of the frequency hopping configuration, the PUSCH mapping type, the PUSCH duration, the number of symbols for the DMRS, the maximum number of additional DMRS symbols or the CDM group type.
18. A network device comprising:
a processor; and
a memory, the memory ( 730 ) comprising instructions which, when executed by the processor, cause the network device to:
detect a preamble from a terminal device, as a part of a random access message, the random access message further comprising a Physical Uplink Shared Channel (PUSCH) wherein the random access message is a message A in a two-step random access procedure; and
determine a DeModulation Reference Signal (DMRS) configuration for the PUSCH, wherein the DMRS configuration comprises a DMRS sequence, in which the DMRS sequence is generated by using an identifier of the preamble as an initialization parameter.