ERROR CORRECTION FOR A PERSISTENT RESOURCE ALLOCATION

• US 20090070650A1
• Filed: 09/04/2008
• Published: 03/12/2009
• Est. Priority Date: 09/11/2007
• Status: Active Grant

• Current Assignee: Quarterhill Inc. (f/k/a Wi-LAN Inc.)
• Original Assignee: Nextwave Broadband Incorporated (AT&T, Inc.)
• Inventors: Asirvatham, Kirupairaj, Bourlas, Yair
• Granted Patent: US 8,423,853 B2
• Time in Patent Office: Days
• US Class Current: 714/748
• CPC Class Codes: H04L 1/0004 applied to control information
• CPC Class Codes: H04L 1/001 applied to control information
• CPC Class Codes: H04L 1/1861 Physical mapping arrangements for ACK signaling see also H04L5/0053
• CPC Class Codes: H04L 1/1887 Scheduling and prioritising arrangements
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/003 Arrangements for allocating sub-channels of the transmission path
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 5/0055 Physical resource allocation for ACK/NACK for physical mapping arrangements in ARQ protocols H04L1/1861
• CPC Class Codes: H04L 5/0096 Indication of changes in allocation
• CPC Class Codes: H04W 72/04 Wireless resource allocation
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 72/0466 the resource being a scrambling code
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

Methods and apparatus for communicating and utilizing persistent allocation of resources are described herein. A base station can allocate persistent resources to a client station, and can associate the client station or persistent resource allocation with a particular shared NACK channel. The base station can monitor the NACK channel for a NACK indicating a map error. The base station can also monitor the resource allocation to implicitly determine a map error. The base station can resend one or more persistent resource allocation information elements in response to the NACK or implicit error determination. A client station having a persistent resource allocation can monitor persistent resource allocation information elements in map messages and can indicate failure to receive a persistent resource allocation information element in a NACK message on a preassigned share NACK channel.

Claims

1. A method of persistent resource allocation, the method comprising:

scheduling a candidate client station for a persistent resource allocation;

associating the candidate client station with a shared NACK channel;

configuring a persistent allocation information element indicating the persistent resource allocation; and

transmitting the persistent allocation information element.

2. The method of claim 1 further comprising configuring the persistent allocation information element to indicate a pseudo random code which defines the shared NACK channel.

3. The method of claim 1 further comprising:

receiving a NACK message over the shared NACK channel; and

transmitting an indication of a set of recent changes made to persistent allocations corresponding to a set of client stations associated with the shared NACK channel.

4. The method of claim 1 further comprising:

receiving a NACK message over the shared NACK channel;

determining that no changes have been made to persistent allocation corresponding to a set of client stations associated with the shared NACK channel; and

transmitting a no-changes-made indication to the set of client station.

5. The method of claim 1, further comprising:

detecting little or no energy from the candidate client station on the persistent resource allocation; and

retransmitting the persistent allocation information element.

6. The method of claim 1, wherein the persistent resource allocation is configured to carry an HARQ packet stream, further comprising:

detecting a series of failed HARQ packet transfers; and

retransmitting the persistent allocation information element.

7. A method of persistent uplink resource allocation, the method comprising:

communicating a persistent resource allocation information element;

receiving a NACK on a predetermine shared NACK channel; and

retransmitting at least a portion of the persistent resource allocation information element to a group of client station associated with the shared NACK channel.

8. A method of persistent uplink resource allocation, the method comprising:

receiving a resource map;

attempting to decode a persistent allocation information element within the resource map; and

selectively transmitting a map NACK over a shared map NACK channel if unable to successfully decode the persistent allocation information element.

9. The method of claim 8 further comprising failing to decode the persistent allocation and, in response, ceasing transmission of data on an uplink channel associated with a most recently received downlink persistent allocation.

10. The method of claim 8, further comprising:

failing to receive an expected response to transmission of the map NACK; and

beginning a map NACK channel recovery process.

11. The method of claim 8 further comprising:

failing to decode the persistent allocation;

receiving a second persistent allocation information element indicating that a NACK message was received and no changes were made; and

continuing operation according to a previously received persistent allocation information element.

12. A method of recovering from an error condition in a system using a shared NACK channel, comprising:

sending an uplink persistent allocation information element specifying a first persistent allocation for a client station;

detecting little or no signal energy from the client station on the first persistent allocation; and

resending the uplink persistent allocation information element to the client station.

13. A method of recovering from an error condition in a system using a shared NACK channel, comprising:

sending an persistent allocation information element specifying a first allocation to a client station for a purpose of carrying HARQ traffic;

detecting a series of failed HARQ packet transfers associated with the first allocation; and

resending the persistent allocation information element to the client station.

14. A method of recovering from an error condition in a system using a shared map NACK channel, comprising:

receiving a persistent allocation information element from a base station for a purpose of carrying HARQ traffic over a first allocation;

detecting a series of failed HARQ packet transfers associated with the first allocation; and

sending a map NACK channel error message to the base station.

15. A method of recovering from an error condition in a system using a shared map NACK channel, comprising:

establishing a global map NACK channel for persistent allocation assignments;

sending an uplink persistent allocation information element to a client station indicating an associated shared NACK channel;

receiving a global NACK message on the global map NACK channel; and

resending a set of recently changed persistent allocation information elements to a set client stations associated with two or more shared NACK channels.

16. A method of recovering from an error condition in a system using a shared NACK channel in a client station, comprising:

failing to receive a persistent allocation information element while no persistent allocation is currently assigned to the client station;

determining that no shared map NACK channel assignment is active; and

sending a global map NACK message on the global map NACK channel

17. A base station comprising:

a group scheduler configured to schedule a candidate client station for persistent uplink resource allocation;

a persistent DL/UL IE generator configured to associate the candidate client station with a shared map NACK channel and to configure a persistent allocation information element identifying a persistent resource allocation; and

a transmitter configured to transmit the persistent allocation information element.

18. The base station of claim 17 further comprising:

a receiver configured to receive a map NACK message over the shared map NACK channel; and

wherein the persistent DL/UL IE generator is further configured to determine a set of recent changes made to persistent allocations corresponding to a set of client stations associated with the shared NACK channel for retransmission.

19. A client station comprising:

a receiver configured to receive a resource map;

a DL/UL-map module configured to determine whether a persistent allocation information element is within the resource map and configured to attempt to decode the persistent allocation information element; and

a NACK module configured to selectively create a map NACK message for transmission over a shared map NACK channel if the DL/UL module is unable to successfully decode the persistent allocation information element.