Random access channel design for narrow bandwidth operation in a wide bandwidth system

• US 9,232,540 B2
• Filed: 09/27/2012
• Issued: 01/05/2016
• Est. Priority Date: 09/30/2011
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Xu, Hao, Montojo, Juan, Gaal, Peter, Chen, Wanshi, Damnjanovic, Jelena M.
• Primary Examiner(s): Shivers, Ashley
• Application Number:
  US13/629,134
• Publication Number:
  US 20130083749A1
• Time in Patent Office: 1,195 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: H04L 1/1854 Scheduling and prioritising arrangements
• CPC Class Codes: H04L 1/1861 Physical mapping arrangements for ACK signaling see also H04L5/0053
• CPC Class Codes: H04L 1/1896 ARQ related signaling
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0044 allocation of payload
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 5/0092 Indication of how the channel is divided
• CPC Class Codes: H04W 74/002 Transmission of channel access control information
• CPC Class Codes: H04W 74/004 in the uplink, i.e. towards network
• CPC Class Codes: H04W 74/006 in the downlink, i.e. towards the terminal
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access

Abstract

A method of wireless communication includes a random access channel configuration for narrow bandwidth operations within a wider LTE system bandwidth. A first random access channel (RACH) configuration is broadcast for a regular device. A second RACH configuration is broadcast for a narrow bandwidth device. The narrow bandwidth device operates in a narrower bandwidth than the regular device.

Claims

1. A method of wireless communication in a narrow bandwidth device of a wider bandwidth system, comprising:

broadcasting, from a base station, a first random access channel (RACH) configuration for a wide bandwidth device;

broadcasting, from the base station, a second RACH configuration for the narrow bandwidth device, wherein the narrow bandwidth device operates in a narrower bandwidth than the wide bandwidth device;

receiving, at the base station, a RACH sequence in accordance with the first RACH configuration or the second RACH configuration; and

transmitting, via a downlink shared channel, a RACH response in response to the received RACH sequence, at least a frequency specified for transmitting the RACH response being configured based at least in part on whether the RACH sequence was received in accordance with the first RACH configuration or the second RACH configuration, the RACH response being transmitted within the narrower bandwidth when the RACH sequence is received with the second RACH configuration, and the RACH response being signaled by a narrowband physical downlink control channel in the narrower bandwidth.

2. The method of claim 1, in which the narrow bandwidth device is a user equipment (UE).

3. The method of claim 1, in which the second RACH configuration includes physical random access channel (PRACH) configuration indices, PRACH root sequences, frequency positions and/or radio network temporary identifier (RNTI).

4. The method of claim 1, further comprising transmitting a message to assign the narrow bandwidth device to a different narrow bandwidth.

5. The method of claim 1, further comprising assigning different uplink and downlink resources to the narrow bandwidth device.

6. The method of claim 1, further comprising transmitting a response to the narrow bandwidth device, the response indicating a new downlink narrow bandwidth.

7. The method of claim 1, further comprising assigning a transmit power, timer offset, and/or number of retransmissions to the narrow bandwidth device that is different from a wide bandwidth device assignment.

8. A method of wireless communication by a narrow bandwidth device, operating in a system including a wider bandwidth, comprising:

receiving, at the narrow bandwidth device from a base station, a second random access channel (RACH) configuration in a defined narrow band that is different from a first RACH configuration which is receivable by a wide bandwidth user equipment (UE);

transmitting, to the base station, a RACH sequence in accordance with the received second RACH configuration; and

receiving, at the narrow bandwidth device from the base station, a RACH response in response to the transmitted RACH sequence, at least a frequency specified for the received RACH response being configured based at least in part on whether the RACH sequence was transmitted in accordance with the first RACH configuration or the second RACH configuration, the RACH response being received within the narrower bandwidth when the RACH sequence is transmitted with the second RACH configuration, and the RACH response being signaled by a narrowband physical downlink control channel in the narrower bandwidth.

9. The method of claim 8, in which the narrow bandwidth device is a UE.

10. The method of claim 8, further comprising receiving a message to assign the narrow bandwidth device to operate in a different narrow bandwidth.

11. The method of claim 8, further comprising receiving a message assigning a transmit power, timer offset, and/or number of retransmissions to the narrow bandwidth device that is different from a wide bandwidth device assignment.

12. A base station configured for wireless communication, comprising:

a memory; and

at least one processor coupled to the memory, the at least one processor being configured;

to broadcast a first random access channel (RACH) configuration for a wide bandwidth device;

to broadcast a second RACH configuration for a narrow bandwidth device, wherein the narrow bandwidth device operates in a narrower bandwidth than the wide bandwidth device;

to receive a RACH sequence in accordance with the first RACH configuration or the second RACH configuration; and

to transmit, via a downlink shared channel, a RACH response in response to the received RACH sequence, at least a frequency specified for transmitting the RACH response being that is configured based at least in part on whether the RACH sequence was received in accordance with the first RACH configuration or the second RACH configuration, the RACH response being transmitted within the narrower bandwidth when the RACH sequence is received with the second RACH configuration, and the RACH response being signaled by a narrowband physical downlink control channel in the narrower bandwidth.

13. The base station of claim 12, in which the narrow bandwidth device is a user equipment (UE).

14. The base station of claim 12, in which the second RACH configuration includes physical random access channel (PRACH) configuration indices, PRACH root sequences, frequency positions and/or radio network temporary identifier (RNTI).

15. The base station of claim 12, in which the at least one processor is further configured to transmit a message to assign the narrow bandwidth device to a different narrow bandwidth.

16. The base station of claim 12, in which the at least one processor is further configured to assign different uplink and downlink resources to the narrow bandwidth device.

17. The base station of claim 12, in which the at least one processor is further configured to transmit a response to the narrow bandwidth device, the response indicating a new downlink narrow bandwidth.

18. The base station of claim 12, in which the at least one processor is further configured to assign a transmit power, timer offset, and/or number of retransmissions to the narrow bandwidth device that is different from a wide bandwidth device assignment.

19. A narrow bandwidth device configured for wireless communication, comprising:

a memory; and

at least one processor coupled to the memory, the at least one processor being configured;

to receive, from a base station, a second random access channel (RACH) configuration in a defined narrow band that is different from a first RACH configuration which is receivable by a wide bandwidth user equipment (UE);

to transmit, to the base station, a RACH sequence in accordance with the received second RACH configuration; and

to receive, from the base station, a RACH response in response to the transmitted RACH sequence, at least a frequency specified for the received RACH response being configured based at least in part on whether the RACH sequence was transmitted in accordance with the first RACH configuration or the second RACH configuration, the RACH response being received within a narrower bandwidth when the RACH sequence is transmitted with the second RACH configuration, and the RACH response being signaled by a narrowband physical downlink control channel in the narrower bandwidth.

20. The narrow bandwidth device of claim 19, in which the narrow bandwidth device is a UE.

21. The narrow bandwidth device of claim 19, in which the processor is further configured to receive a message to assign the narrow bandwidth device to operate in a different narrow bandwidth.

22. The narrow bandwidth device of claim 19, in which the processor is further configured to receive a message assigning a transmit power, timer offset, and/or number of retransmissions to the narrow bandwidth device that is different from a wide bandwidth device assignment.

23. An apparatus for wireless communication, comprising:

means for broadcasting, from a base station, a first random access channel (RACH) configuration for a wide bandwidth device;

means for broadcasting, from the base station, a second RACH configuration for a narrow bandwidth device, wherein the narrow bandwidth device operates in a narrower bandwidth than the wide bandwidth device;

means for receiving, at the base station, a RACH sequence in accordance with the first RACH configuration or the second RACH configuration; and

means for transmitting, via a downlink shared channel, a RACH response in response to the received RACH sequence, at least a frequency specified for transmitting the RACH response being that is configured based at least in part on whether the RACH sequence was received in accordance with the first RACH configuration or the second RACH configuration, the RACH response being transmitted within the narrower bandwidth when the RACH sequence is received with the second RACH configuration, and the RACH response being signaled by a narrowband physical downlink control channel in the narrower bandwidth.

24. An apparatus for wireless communication, comprising:

means for receiving, at a narrow bandwidth device from a base station, a second random access channel (RACH) configuration in a defined narrow band that is different from a first RACH configuration received by a wide bandwidth user equipment (UE);

means for transmitting, to the base station, a RACH sequence in accordance with the received second RACH configuration; and

means for receiving, at the narrow bandwidth device from the base station, a RACH response in response to the transmitted RACH sequence, at least a frequency specified for the received RACH response being configured based at least in part on whether the RACH sequence was transmitted in accordance with the first RACH configuration or the second RACH configuration, the RACH response being received within a narrower bandwidth when the RACH sequence is transmitted with the second RACH configuration, and the RACH response being signaled by a narrowband physical downlink control channel in the narrower bandwidth.

25. A non-transitory computer-readable medium having non-transitory program code recorded thereon, the program code comprising:

program code to broadcast, from a base station, a first random access channel (RACH) configuration for a wide bandwidth device;

program code to broadcast, from the base station, a second RACH configuration for a narrow bandwidth device, wherein the narrow bandwidth device operates in a narrower bandwidth than the wide bandwidth device;

program code to receive, at the base station, a RACH sequence in accordance with the first RACH configuration or the second RACH configuration; and

program code to transmit, via a downlink shared channel, a RACH response in response to the received RACH sequence, at least a frequency specified for transmitting the RACH response being that is configured based at least in part on whether the RACH sequence was received in accordance with the first RACH configuration or the second RACH configuration, the RACH response being transmitted within the narrower bandwidth when the RACH sequence is received with the second RACH configuration, and the RACH response being signaled by a narrowband physical downlink control channel in the narrower bandwidth.

26. A non-transitory computer-readable medium having non-transitory program code recorded thereon, the program code comprising:

program code to receive, at a narrow bandwidth device from a base station, a second random access channel (RACH) configuration in a defined narrow band that is different from a first RACH configuration which is receivable by a wide bandwidth user equipment (UE);

program code to transmit, to the base station, a RACH sequence in accordance with the received second RACH configuration; and

program code to receive, at the narrow bandwidth device from the base station, a RACH response in response to the transmitted RACH sequence, at least a frequency specified for the received RACH response being configured based at least in part on whether the RACH sequence was transmitted in accordance with the first RACH configuration or the second RACH configuration, the RACH response being received within a narrower bandwidth when the RACH sequence is transmitted with the second RACH configuration, and the RACH response being signaled by a narrowband physical downlink control channel in the narrower bandwidth.