NEW RADIO RANDOM ACCESS IN BEAMFORMING SYSTEMS
A method and system for determining beam reciprocity for a beam of a wireless transmit/receive unit (WTRU) are disclosed. A WTRU may determine a downlink (DL) beam for synchronization. Then, the WTRU may determine transmission reception point (TRP) transmit (TX)/receive (RX) beam correspondence information (BCI) using the determined DL beam. Further, the WTRU may determine a number of WTRU TX beams based on at least the TRP TX/RX BCI. Also, the WTRU may determine a set of WTRU TX beams based on at least the DL beam and the TRP TX/RX BCI, wherein determining the set includes determining one or more WTRU TX beam directions. In addition, the WTRU may transmit data using the determined set of WTRU TX beams. In an example, the determination of the TRP TX/RX BCI may be based on a received TRP TX/RX BCI.
1 . A method for initial access in a wireless transmit/receive unit (WTRU), the method comprising:
determining, by the WTRU, a downlink (DL) beam for synchronization;
using the determined DL beam, determining, by the WTRU, transmission reception point (TRP) transmit (TX)/receive (RX) beam correspondence information (BCI) based on a de-masking of a new radio (NR)-physical broadcast channel (PBCH) cyclic redundancy check (CRC) mask, wherein the determined DL beam is for reception of an NR-PBCH from a TRP, wherein the NR-PBCH is a synchronization signal (SS)/PBCH and wherein the SS/PBCH includes an SS block time index;
determining, by the WTRU, a number of WTRU TX beams based on at least the determined TRP TX/RX BCI;
determining, by the WTRU, a set of WTRU TX beams based on at least the determined DL beam and the determined TRP TX/RX BCI, wherein determining the set of WTRU TX beams includes determining one or more WTRU TX beam directions; and
transmitting, by the WTRU, data using the determined set of WTRU TX beams.
2 . The method of claim 1 , wherein the determination of the TRP TX/RX BCI is based on a received TRP TX/RX BCI.
3 . The method of claim 1 , wherein the determination of the TRP TX/RX BCI is based on an NR-PBCH payload.
4 - 6 . (canceled)
7 . The method of claim 1 , wherein the TX/RX BCI includes at least one of a TX/RX beam width relationship or a TX/RX beam direction relationship.
8 . The method of claim 1 , wherein the determination of the set of WTRU TX beams is further based on the determined number of WTRU TX beams.
9 . The method of claim 1 , further comprising:
determining, by the WTRU, a preamble for a random access channel (RACH) procedure based on resources used by the determined DL beam; and
transmitting, by the WTRU, the preamble.
10 . The method of claim 9 , wherein the preamble is transmitted using preamble time resources mapped to a gNB RX beam.
11 . A wireless transmit/receive unit (WTRU), the WTRU comprising:
a processor; and
a transceiver operatively coupled to the processor;
wherein the processor is configured to determine a downlink (DL) beam for synchronization;
wherein the processor is configured, using the determined UL beam, to determine transmission reception point (TRP) transmit (TX)/receive (RX) beam correspondence information (BCI) based on a de-masking of a new radio (NR)-physical broadcast channel (PBCH) cyclic redundancy check (CRC) mask, wherein the determined DL beam is for reception of an NR-PBCH from a TRP, wherein the NR-PBCH is a synchronization signal (SS)/PBCH and wherein the SS/PBCH includes an SS block time index;
wherein the processor is configured to determine a number of WTRU TX beams based on at least the determined TRP TX/RX BC;
wherein the processor is configured to determine a set of WTRU TX beams based on at least the determined DL beam and the TRP TX/RX BCI, wherein determining the set of WTRU TX beams includes determining one or more WTRU TX beam directions; and
wherein the transceiver is configured to transmit data using the determined set of WTRU TX beams.
12 . The WTRU of claim 11 , wherein the determination of the TRP TX/RX BCI is based on a received TRP TX/RX BCI.
13 . The WTRU of claim 11 , wherein the determination of the TRP TX/RX BCI is based on an NR-PBCH payload.
14 .- 16 . (canceled)
17 . The WTRU of claim 11 , wherein the TX/RX BCI includes at least one of a TX/RX beam width relationship or a TX/RX beam direction relationship.
18 . The WTRU of claim 11 , wherein the determination of the set of WTRU TX beams is further based on the determined number of WTRU TX beams
19 . The WTRU of claim 11 , further comprising:
the processor configured to determine a preamble for a random access channel (RACH) procedure based on resources used by the determined DL beam; and
the transceiver configured to transmit the preamble.
20 . The WTRU of claim 19 , wherein the preamble is transmitted using preamble time resources mapped to a gNB RX beam.
21 . The method of claim 1 , wherein the determination of the TRP TX/RX BCI is based on one or more NR-PBCH resources.
22 . The method of claim 1 , wherein the determination of the TRP TX/RX BCI is based on a system information block (SIB).
23 . The method of claim 1 , wherein the TRP TX/RX BCI includes an indication of a correspondence type.
24 . The WTRU of claim 11 , wherein the determination of the TRP TX/RX BCI is based on one or more NR-PBCH resources.
25 . The WTRU of claim 11 , wherein the determination of the TRP TX/RX BCI is based on a system information block (SIB).
26 . The WTRU of claim 11 , wherein the TRP TX/RX BCI includes an indication of a correspondence type.