Narrowband internet of things random access channel configuration design

Patent metadata

Field	Value
Publication number	US-11272550-B2
Application number	US-201716084805-A
Country	US
Kind code	B2
Filing date	Mar 16, 2017
Priority date	Mar 16, 2016
Publication date	Mar 8, 2022
Grant date	Mar 8, 2022

Abstract

According to one aspect of the disclosure, a wireless device is configured to transmit a random access preamble. The wireless device includes processing circuitry. The processing circuitry is configured to obtain a tone index, and determine a location within a frequency band for transmitting the random access preamble based on the obtained tone index.

First claim

What is claimed is:

1. A wireless device configured to transmit a random access preamble, the wireless device comprising:
processing circuitry, the processing circuitry configured to:
obtain at least one tone index of a plurality of tone indices, each tone index of the plurality of tone indices corresponding to a respective frequency location of a plurality of frequency locations within a time-frequency grid, each tone index of the plurality of tone indices indicating one starting subcarrier of one narrowband physical random access channel, NPRACH, band of a plurality of NPRACH bands within a frequency band, for each NPRACH band of the plurality of NPRACH bands, three bits in one system information block indicate one tone index, the obtained at least one tone index comprising a first tone index and a second tone index:
the first tone index indicating a first starting subcarrier of a first NPRACH band within the frequency band, the first NPRACH band being associated with a first coverage class; and
the second tone index indicating a second starting subcarrier of a second NPRACH band within the frequency band, the second NPRACH band being associated with a second coverage class, the first tone index and the second tone index ranging from 0 to 36;

determine a coverage class;
select one of the first tone index and the second tone index from the obtained at least one tone index based on the determined coverage class; and
determine a location within the frequency band for transmitting the random access preamble based on the selected one of the first tone index and the second tone index.

2. The wireless device of claim 1 , wherein the processing circuitry is further configured to cause transmission of the random access preamble using the determined location within the frequency band.

3. The wireless device of claim 1 , wherein the processing circuitry is further configured to receive the one system information block; and the obtaining of the at least one tone index being based on the received one system information block.

4. The wireless device of claim 3 , wherein the system information is received via radio resource control (RRC) signaling.

5. The wireless device of claim 1 , wherein the at least one tone index is based on at least one of system bandwidth, a number of tones per random access channel band and a number of random access channel bands.

6. The wireless device of claim 1 , wherein the processing circuitry is further configured to obtain at least a configuration index indicating at least one subframe at which the transmission of the random access preamble is to start.

7. The wireless device of claim 6 , wherein the configuration index further indicates a cyclic prefix (CP) length.

8. The wireless device of claim 1 , wherein the frequency band has a bandwidth of 180 kHz, the frequency band corresponding to a plurality of subcarriers.

9. A method for a wireless device for transmitting a random access preamble, the method comprising:
obtaining at least one tone index of a plurality of tone indices, each tone index of the plurality of tone indices corresponding to a respective frequency location of a plurality of frequency locations within a time-frequency grid, each tone index of the plurality of tone indices indicating one starting subcarrier of one narrowband physical random access channel, NPRACH, band of a plurality of NPRACH bands within a frequency band, for each NPRACH band of the plurality of NPRACH bands, three bits in one system information block indicate one tone index, the obtained at least one tone index comprising a first tone index and a second tone index:
the first tone index indicating a first starting subcarrier of a first NPRACH band within the frequency band, the first NPRACH band being associated with a first coverage class; and
the second tone index indicating a second starting subcarrier of a second NPRACH band within the frequency band, the second NPRACH band being associated with a second coverage class, the first tone index and the second tone index ranging from 0 to 36;

determining a coverage class;
selecting one of the first tone index and the second tone index from the obtained at least one tone index based on the determined coverage class; and
determining a location within the frequency band for transmitting the random access preamble based on the selected one of the first tone index and the second tone index.

10. The method of claim 9 , further comprising causing transmission of the random access preamble using the determined location within the frequency band.

11. The method of claim 9 , further comprising receiving the one system information block; and the obtaining of the at least one tone index being based on the received one system information block.

12. The method of claim 11 , wherein the system information is received via radio resource control (RRC) signaling.

13. The method of claim 9 , wherein the at least one tone index is based on at least one of system bandwidth, a number of tones per random access channel band and a number of random access channel bands.

14. The method of claim 9 , further comprising obtaining at least a configuration index indicating at least one subframe at which the transmission of the random access preamble is to start.

15. The method of claim 14 , wherein the configuration index further indicates a cyclic prefix (CP) length.

16. The method of claim 9 , wherein the frequency band has a bandwidth of 180 kHz, the frequency band corresponding to a plurality of subcarriers.

17. A network node configured to receive a random access preamble from a wireless device, the network node comprising:
processing circuitry, the processing circuitry configured to:
transmit an indication of at least one tone index of a plurality of tone indices to the wireless device, each tone index of the plurality of tone indices corresponding to a respective frequency location of a plurality of frequency locations within a time-frequency grid, each tone index of the plurality of tone indices indicating one starting subcarrier of one narrowband physical random access channel, NPRACH, band of a plurality of NPRACH bands within a frequency band, for each NPRACH band of the plurality of NPRACH bands, three bits in one system information block indicate one tone index, the transmitted at least one tone index comprising a first tone index and a second tone index:
the first tone index indicating a first starting subcarrier of a first NPRACH band within the frequency band, the first NPRACH band being associated with a first coverage class;
the second tone index indicating a second starting subcarrier of a second NPRACH band within the frequency band, the second NPRACH band being associated with a second coverage class, the first tone index and the second tone index ranging from 0 to 36; and
the at least one tone index indicating at least one location within the time-frequency grid associated with the random access preamble; and

receive the random access preamble on a location within the frequency band, the location corresponding to one of the first tone index and the second tone index comprised in the indicated at least one tone index and the one of the first tone index and the second tone index being based on a coverage class associated with the wireless device.

18. The network node of claim 17 , wherein the random access preamble corresponds to a frequency hopping random access preamble over a plurality of subcarriers.

19. The method of claim 17 , wherein the indication of the location with

Assignees

• Ericsson Telefon Ab L M

Inventors

• Lin Xingqin
• Adhikary Ansuman
• Bergman Johan
• Blankenship Yufei
• Grövlen Asbjörn
• Shokri Razaghi Hazhir
• Sui Yutao
• Wang Yi-Pin Eric

Classifications

• H04W74/0833

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

• H04L5/0012 Primary

  Hopping in multicarrier systems · CPC title

• Y02D30/70

  in wireless communication networks · CPC title

• H04W76/27

  Transitions between radio resource control [RRC] states · CPC title

• H04W72/0453

  Resources in frequency domain, e.g. a carrier in FDMA · CPC title