PRACH configuration for NR over NTN
Systems and methods of the present disclosure are directed to Physical Random Access Channel (PRACH) over NTN (Non-Terrestrial-Networks). For example, a method performed by a wireless communication device for random access includes determining one or more random access occasions for transmission of a random access channel. The method includes transmitting the random access channel on the determined one or more random access occasions.
1 . A method performed by a wireless communication device for random access, the method comprising:
determining one or more random access occasions for transmission of a random access channel, determining the one or more random access occasions for transmission of a random access channel comprising determining the one or more random access occasions for transmission of the random access channel with two or more sequences, determining the one or more random access occasions for transmission of the random access channel with two or more sequences comprising determining two random access occasions for transmission of the random access channel with two sequences, determining two random access occasions for transmission of the random access channel with two sequences comprising receiving a random access parameter that indicates one of a plurality of defined random access configurations defined for transmission of a random access channel with two sequences and determining the two random access occasions based on the received random access parameter, the two random access occasions concatenated in the time-domain and the plurality of defined random access configurations defined for transmission of a random access channel with two sequences comprised in a table, the table a table defined for Non-Terrestrial Network, NTN, specific random access, and the random access parameter an index to the table; and
transmitting the random access channel on the determined one or more random access occasions, transmitting the random access channel comprising transmitting the random access channel with the two or more sequences on the determined one or more random access occasions.
2 . The method of claim 1 , wherein one of:
the index is an index defined specifically for NTN specific random access; and
the index is an index defined for both normal random access and NTN specific random access.
3 . The method of claim 1 , wherein determining two random access occasions for transmission of the random access channel with two sequences comprises:
determining that a random access parameter that indicates one of a plurality of defined random access configurations defined for transmission of a random access channel with two sequences has been configured for the wireless communication device; and
determining the two random access occasions and a random access preamble format for the two sequences based on the random access parameter responsive to determining that the random access parameter has been configured for the wireless communication device.
4 . The method of claim 1 , wherein determining two random access occasions for transmission of the random access channel with two sequences comprises indirectly obtaining a new Physical Random Access Channel, PRACH, configuration comprising the two random access occasions from a legacy PRACH configuration.
5 . The method of claim 1 , wherein determining two random access occasions for transmission of the random access channel with two sequences comprises:
receiving a random access parameter that defines a legacy random access configuration; and
reinterpreting the legacy random access configuration to infer a new random access configuration that comprises the two random access occasions for transmission of the random access channel with two sequences.
6 . The method of claim 5 , wherein reinterpreting the legacy random access configuration to infer the new random access configuration that comprises the two random access occasions for transmission of the random access channel with two sequences comprises reinterpreting a New Radio, NR, Physical Random Access Channel, PRACH, configuration for transmission of a format 1 or format 2 preamble as a NR PRACH configuration for transmission of the two sequences as two NR PRACH format 0 preambles.
7 . The method of claim 5 , wherein reinterpreting the legacy random access configuration to infer the new random access configuration that comprises the two random access occasions for transmission of the random access channel with two sequences comprises reinterpreting a New Radio, NR, Physical Random Access Channel, PRACH, configuration for transmission of a format 3 preamble as a NR PRACH configuration for transmission of the two sequences as a NR PRACH format 0 preamble followed by a NR PRACH format 1 preamble.
8 . The method of claim 1 , wherein determining two random access occasions for transmission of the random access channel with two sequences comprises:
receiving a random access parameter that indicates a random access configuration; and
selecting two consecutive random access occasions from a set of random access occasions defined by the random access configuration as the two random access occasions for transmission of the random access channel with two sequences.
9 . The method of claim 1 , wherein determining two random access occasions for transmission of the random access channel with two sequences comprises:
receiving a random access parameter that indicates a random access configuration, the random access configuration defining one or more existing random access occasions; and
selecting the two or more random access occasions for transmission of the random access channel with two sequences from among a set of random access occasions that comprises the one or more existing random access occasions and one or more additional random access occasions that are time division multiplexed with the one or more existing random access occasions.
10 . The method of claim 1 , wherein the two random access occasions are concatenated in the frequency-domain.
11 . A wireless communication device for random access, the wireless communication device being configured to:
determine one or more random access occasions for transmission of a random access channel, determining the one or more random access occasions for transmission of a random access channel comprising determining the one or more random access occasions for transmission of the random access channel with two or more sequences, determining the one or more random access occasions for transmission of the random access channel with two or more sequences comprising determining two random access occasions for transmission of the random access channel with two sequences, determining two random access occasions for transmission of the random access channel with two sequences comprising receiving a random access parameter that indicates one of a plurality of defined random access configurations defined for transmission of a random access channel with two sequences and determining the two random access occasions based on the received random access parameter, the two random access occasions concatenated in the time-domain and the plurality of defined random access configurations defined for transmission of a random access channel with two sequences comprised in a table, the table a table defined for Non-Terrestrial Network, NTN, specific random access, and the random access parameter an index to the table; and
transmit the random access channel on the determined one or more random access occasions, transmitting the random access channel comprising transmitting the random access channel with the two or more sequences on the determined one or more random access occasions.
12 . A method performed by radio access node for configuring a wireless communication device for random access, the method comprising:
configuring the wireless communication device with one or more random access occasions for transmission of a random access channel with two or more sequences;
sending a random access parameter that indicates one of a plurality of defined random access configurations defined for transmission of a random access channel with two sequences, the plurality of defined random access configurations defined for transmission of a random access channel with two sequences comprised in a table, and the random access parameter an index to the table, the table a table defined for Non-Terrestrial Network, NTN, specific random access; and
configuring the wireless device with the table.
13 . The method of claim 12 , further comprising receiving a random access channel with two or more sequences on the configured one or more random access occasions.
14 . A radio access node for configuring a wireless communication device for random access, the radio access node configured to:
configure the wireless communication device with one or more random access occasions for transmission of a random access channel with two or more sequences;
send a random access parameter that indicates one of a plurality of defined random access configurations defined for transmission of a random access channel with two sequences, the plurality of defined random access configurations defined for transmission of a random access channel with two sequences comprised in a table, and the random access parameter an index to the table, the table a table defined for Non-Terrestrial Network, NTN, specific random access; and
configure the wireless device with the table.