New Radio Random Access in Beamforming Systems

Abstract

A method and system for determining beam reciprocity for a beam of a wireless transmit / receive unit (WTRU) is provided. [Solution] The WTRU can determine the downlink (DL) beam for synchronization, use the determined DL beam to determine the transmit / receive point (TRP) transmit (TX) / receive (RX) beam correspondence information (BCI), determine the number of WTRU TX beams based on at least the TRP TX / RX BCI, and determine a set of WTRU TX beams based on at least the DL beam and the TRP TX / RX BCI. Determining this set includes determining one or more WTRU TX beam directions. The WTRU can also transmit data using the determined set of WTRU TX beams. The determination of the TRP TX / RX BCI may be based on the received TRP TX / RX BCI.

Claims

1. A wireless transmitter / receiver unit (WTRU), Determine the beam set, Based on a sequence indicating association with a beam signaled by a physical broadcast channel (PBCH) and one or more payload bits of the PBCH, the representation of the beam in the set of beams is determined. Based on the display of the beam, a physical random access (PRACH) resource is determined. Based on the PRACH resource, a PRACH preamble is sent to the network node, and the PRACH preamble is associated with a random access procedure. Processor configured in such a way A WTRU characterized by having the following features.

2. The WTRU according to claim 1, characterized in that the indicator of the beam is an index.

3. The WTRU according to claim 1, wherein the processor is further configured to receive the beam, and the beam includes at least a synchronization signal, a reference signal, and the PBCH.

4. The WTRU according to claim 1, characterized in that the PRACH preamble is associated with the beam.

5. The WTRU according to claim 1, further configured to send the PRACH preamble to the network node based on the PRACH resources and the beam.

6. The WTRU according to claim 1, wherein the processor is further configured to receive a random access response (RAR) from the network node, the RAR indicating that the network node has detected the PRACH preamble.

7. The WTRU according to claim 6, characterized in that the RAR includes at least one timing advance value.

8. The processor is configured to determine the representation of the beam based on at least one of the sequence indicating the association with the beam signaled by the PBCH and one or more payload bits of the PBCH, Determine a mask which will be applied to a cyclic redundancy check (CRC) associated with one or more payload bits, and the mask will be associated with at least one reciprocity mode or association mode. The display of the beam is determined based on the mask. The WTRU according to claim 1, characterized in that it includes the processor configured as described above.

9. The WTRU according to claim 1, characterized in that the PRACH resource includes one of a preamble resource, a time resource, or a frequency resource.

10. The WTRU according to claim 1, characterized in that the PRACH resource is determined based on the indication of the beam and at least one of a time resource or a frequency resource.

11. A method performed by a wireless transmitter / receiver unit (WTRU), Determining the beam set, Determining the representation of the beam in the set of beams based on a sequence indicating association with a beam signaled by a physical broadcast channel (PBCH) and one or more payload bits of the PBCH, Determining a physical random access (PRACH) resource based on the aforementioned display of the beam, The process involves sending a PRACH preamble to a network node based on the PRACH resource, wherein the PRACH preamble is associated with a random access procedure. A method characterized by comprising:

12. The method according to 11, characterized in that the display of the beam is an index.

13. The method according to 11, further comprising receiving the beam, wherein the beam includes at least a synchronization signal, a reference signal, and the PBCH.

14. The method according to 11, characterized in that the PRACH preamble is associated with the beam.

15. The method according to 11, further comprising sending the PRACH preamble to the network node based on the PRACH resources and the beam.

16. The method according to 11, further comprising receiving a random access response (RAR) from the network node, wherein the RAR indicates that the network node has detected the PRACH preamble.

17. The method according to 16, characterized in that the RAR includes at least one timing advance value.

18. Determining the representation of the beam based on at least one of the sequence indicating the association with the beam signaled by the PBCH and one or more payload bits of the PBCH is: Determining a mask to be applied to a cyclic redundancy check (CRC) associated with one or more payload bits, wherein the mask is associated with at least one of the reciprocity mode or association mode, The display of the beam is determined based on the mask. The method according to 11, characterized by including the following:

19. The method according to 11, characterized in that the PRACH resource includes one of a preamble resource, a time resource, or a frequency resource.

20. The method according to 11, characterized in that the PRACH resource is determined based on the indication of the beam and at least one of a time resource or a frequency resource.

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