Nb lte prach design

Patent metadata

Field	Value
Publication number	US-2020112413-A1
Application number	US-201916708832-A
Country	US
Kind code	A1
Filing date	Dec 10, 2019
Priority date	Jul 27, 2015
Publication date	Apr 9, 2020
Grant date	—

Abstract

A method in a user equipment is disclosed. The method comprises generating a narrowband random access preamble for a narrowband random access procedure, the narrowband random access preamble comprising a Zadoff-Chu sequence. The method comprises transmitting, to a network node, the generated narrowband random access preamble via a narrowband physical random access channel (PRACH) according to a narrowband PRACH format, wherein the narrowband PRACH is frequency multiplexed with a physical uplink shared channel (PUSCH) and comprises: at least one narrowband PRACH slot having a narrowband PRACH slot duration; and a narrowband PRACH period.

First claim

1 . A method in a user equipment, comprising:
transmitting, to a network node, a narrowband random access message via a narrowband physical random access channel (PRACH), wherein the narrowband PRACH includes at least one narrowband PRACH slot having a plurality of segments and the narrowband random access message includes a narrowband random access preamble repeated in a plurality of segments of the at least one narrowband PRACH slot.

2 . The method of claim 1 , further comprising:
selecting a number of times to repeat the narrowband random access preamble.

3 . The method of claim 2 , further comprising:
determining a coverage level of the user equipment, wherein the number of times to repeat the narrowband random access preamble is selected based on the determined coverage level.

4 . The method of claim 3 , wherein the coverage level of the user equipment comprises one or more of a basic coverage level, a robust coverage level, and an extreme coverage level.

5 . The method of claim 1 , wherein the plurality of segments are consecutive.

6 . The method of claim 1 , wherein the narrowband PRACH is frequency multiplexed with a narrowband physical uplink shared channel (PUSCH).

7 . The method of claim 1 , wherein the narrowband PRACH has a narrowband PRACH slot duration and a narrowband PRACH period, wherein the narrowband PRACH slot duration and the narrowband PRACH period are based on one or both of:
a cell load of a cell associated with the network node; and a cell size of the cell associated with the network node.

8 . A method in a network node, comprising:
receiving, from a user equipment, a narrowband random access message via a narrowband PRACH, wherein the narrowband PRACH includes at least one narrowband PRACH slot having a plurality of segments and the narrowband random access message includes a narrowband random access preamble repeated in a plurality of segments of the at least one narrowband PRACH slot.

9 . The method of claim 8 , wherein the plurality of segments are consecutive.

10 . The method of claim 8 , wherein the narrowband PRACH is frequency multiplexed with a PUSCH.

11 . The method of claim 8 , wherein the narrowband PRACH has a narrowband PRACH slot duration and a narrowband PRACH period, wherein the narrowband PRACH slot duration and the narrowband PRACH period are based on one or both of:
a cell load of a cell associated with the network node; and a cell size of the cell associated with the network node.

12 . A user equipment, comprising:
one or more processors, the one or more processors configured to:
transmit, to a network node, a narrowband random access message via a narrowband PRACH,
wherein the narrowband PRACH includes at least one narrowband PRACH slot having a plurality of segments and the narrowband random access message includes a narrowband random access preamble repeated in a plurality of segments of the at least one narrowband PRACH slot.

13 . The user equipment of claim 12 , wherein the one or more processors are configured to select a number of times to repeat the narrowband random access preamble.

14 . The user equipment of claim 12 , wherein the one or more processors are configured to determine a coverage level of the user equipment, wherein the number of times to repeat the narrowband random access preamble is selected based on the determined coverage level.

15 . The user equipment of claim 14 , wherein the coverage level of the user equipment comprises one or more of a basic coverage level, a robust coverage level, and an extreme coverage level.

16 . The user equipment of claim 12 , wherein the plurality of segments are consecutive.

17 . The user equipment of claim 12 , wherein the narrowband PRACH is frequency multiplexed with a narrowband PUSCH.

18 . The user equipment of claim 12 , wherein the narrowband PRACH has a narrowband PRACH slot duration and a narrowband PRACH period, wherein the narrowband PRACH slot duration and the narrowband PRACH period are based on one or both of:
a cell load of a cell associated with the network node; and a cell size of the cell associated with the network node.

19 . A network node, comprising:
one or more processors, the one or more processors configured to:
receive, from a user equipment, a narrowband random access message via a narrowband PRACH,
wherein the narrowband PRACH includes at least one narrowband PRACH slot having a plurality of segments and the narrowband random access message includes a narrowband random access preamble repeated in a plurality of segments of the at least one narrowband PRACH slot.

20 . The network node of claim 19 , wherein the plurality of segments are consecutive.

21 . The network node of claim 19 , wherein the narrowband PRACH is frequency multiplexed with a PUSCH.

22 . The network node of claim 19 , wherein the narrowband PRACH has a narrowband PRACH slot duration and a narrowband PRACH period, wherein the narrowband PRACH slot duration and the narrowband PRACH period are based on one or both of:
a cell load of a cell associated with the network node; and a cell size of the cell associated with the network node.

Assignees

• Ericsson Telefon Ab L M

Inventors

• Lin Xingqin
• Adhikary Ansuman
• Johansson Niklas
• Wang Yi-Pin Eric

Classifications

• H04L5/0053 Primary

  Allocation of signalling, i.e. of overhead other than pilot signals · CPC title

• H04W74/0866

  using a dedicated channel for access · CPC title

• H04L27/2605

  Symbol extensions, e.g. Zero Tail, Unique Word [UW] · CPC title

• H04W74/0833 Primary

  Random access procedures, e.g. with 4-step access · CPC title

• H04W72/0486

  Electricity · mapped topic