Random Access Channel Hopping for Frequency Division Multiplexing Access Systems

• US 20080267126A1
• Filed: 11/03/2006
• Published: 10/30/2008
• Est. Priority Date: 11/04/2005
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Fischer, Patrick, Vujcic, Dragan
• Granted Patent: US 8,559,362 B2
• Time in Patent Office: Days
• US Class Current: 370/330
• CPC Class Codes: H04B 7/2637 for logical channel control
• CPC Class Codes: H04J 13/102 Combining codes
• CPC Class Codes: H04L 5/023 Multiplexing of multicarrier modulation signals multicarrier modulation H04L27/2601
• CPC Class Codes: H04W 74/0866 using a dedicated channel for access
• CPC Class Codes: H04W 88/02 Terminal devices
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

A method of coordinating resources for repetition of random access bursts performed by a mobile terminal, the method comprising: determining groups of access slots based on parameters from a network, wherein each access slot is defined by any combination of frequency, time and code, and the access slots are organized according to a frequency pattern; transmitting an access burst on an access slot from a chosen group of access slots; and re-transmitting the access burst on the next access slot from the chosen group of access slots.

Claims

1. A method of coordinating resources for repetition of random access bursts performed by a mobile terminal, the method comprising:

determining groups of access slots based on parameters from a network, wherein each access slot is defined by any combination of frequency, time and code, and the access slots are organized according to a frequency pattern;

transmitting an access burst on an access slot from a chosen group of access slots; and

re-transmitting the access burst on the next access slot from the chosen group of access slots.

2. The method of claim 1, wherein the re-transmitting is performed when a negative acknowledgement is received or when no response is received from the network.

3. The method of claim 1, wherein the frequency pattern is static or dynamic.

4. The method of claim 1, wherein the frequency pattern is based on a RACH Allocation Index Offset.

5. The method of claim 1, wherein the determining is based on dedicated signaling or broadcast signaling or multicast signaling.

6. The method of claim 1, wherein the groups of access slots comprises a first group of access slots for path loss greater than or equal to a threshold value.

7. The method of claim 6, further comprising a second group of access slots for path loss less than the threshold value.

8. The method of claim 7, wherein at least one access slot of the first group is in a single sub-frame or at least one access slot of the second group is in a single sub-frame.

9. The method of claim 7, wherein an access slot of the first group and an access slot of the second group are in the same sub-frame.

10. The method of claim 7, wherein one or more subsequent sub-frames contain scheduled data transmission information.

11. The method of claim 1, wherein the transmitting step is performed for an unsynchronized RACH procedure comprising:

transmitting to a network, on a contention based channel, a preamble and a message payload containing some information on uplink resources needed, priority, reason for random access, and possibly random Id to assist in resolution of contention;

receiving, from the network, scheduled resources containing necessary timing advance information to be used on the uplink and requested scheduling grant, and other required information; and

transmitting L3 messages, MAC data or control PDUs on the scheduled resources.

12. The method of claim 1, wherein the transmitting step is performed for an unsynchronized RACH procedure comprising:

transmitting to a network, on a contention based channel, only a preamble;

receiving signalling resources allocated from the network;

sending a scheduling grant on the signaling resources to allow the network to adjust resource allocation depending on what the mobile terminal needs for message payload part transmission;

receiving, from the network, scheduled resources containing necessary timing advance information to be used on the uplink and requested scheduling grant, and other required information; and

transmitting L3 messages, MAC data or control PDUs on the scheduled resources.

13. The method of claim 1, wherein the transmitting step is performed for a synchronized RACH procedure comprising:

transmitting to a network, a preamble together with a C-RNTI, a RR, and a reason for random access, on a specific resource reserved for a RACH procedure, where the C-RNTI and the RR are protected by channel coding; and

receiving uplink data resource allocation from the network.

14. The method of claim 13, wherein the C-RNTI and the RR are protected by channel coding, as well as additional redundancy.

15. The method of claim 1, wherein the transmitting step is performed for a synchronized RACH procedure comprising:

transmitting to a network, a preamble on a specific resource reserved for a RACH procedure;

receiving specific resource allocation from the network;

transmitting a RR, a C-RNTI, a reason for random access, and part of a RRC message on the allocated specific resource; and

receiving uplink data resource allocation from the network.

16. A method of coordinating resources for repetition of random access bursts performed by a network, the method comprising:

configuring parameters that allow a terminal to determine groups of access slots, wherein each access slot is defined by any combination of frequency, time and code, and the access slots are organized according to a frequency pattern;

using the configured parameters to determine when resources should not be allocated for other uplink transmissions; and

transmitting the configured parameters to the terminal.

17. The method of claim 16, further comprising:

receiving an access burst transmitted by a terminal on any access slot.

18. The method of claim 17, further comprising:

receiving the access burst re-transmitted by the terminal on the next access slot belonging to the same group as the previous access slot.

19. The method of claim 16, wherein the parameters comprise a RACH Allocation Index Offset.