Error correction for a persistent resource allocation
View Patent ↗Methods and apparatus for communicating and utilizing persistent allocation of resources are described herein. A base station may allocate persistent resources to a client station, and may associate the client station or persistent resource allocation with a particular shared NACK channel. The base station may monitor the NACK channel for a NACK indicating a map error. The base station may monitor the resource allocation to implicitly determine a map error. The base station may 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 may monitor persistent resource allocation information elements in map messages and/or may indicate failure to receive a persistent resource allocation information element in a NACK message on a shared NACK channel.
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 dedicated affirmative acknowledgment (ACK) channel and a shared negative acknowledgment (NACK) channel;
configuring a persistent allocation information element indicating the persistent resource allocation, the dedicated ACK channel, and the shared NACK channel; and
transmitting the persistent allocation information element.
2. The method of claim 1 further comprising using a pseudo random code to define the shared NACK channel indicated in the persistent allocation information element.
3. The method of claim 1 further comprising:
determining an error condition based on at least one of:
receiving a NACK indication over the shared NACK channel;
detecting little or no energy from the candidate client station on the persistent resource allocation; and
missing an ACK indication over the dedicated ACK channel.
4. The method of claim 3 further comprising:
determining, based on changes made to persistent allocation corresponding to one or more client station of a group of client stations associated with the shared NACK channel, a set of recent changes; and
transmitting an indication of the set of recent changes made to persistent allocations corresponding to at least one of the group of client stations associated with the shared NACK channel, wherein a no-changes-made indication is transmitted if the set of recent changes is empty.
5. The method of claim 3 , further comprising:
retransmitting at least a portion of the persistent allocation information element.
6. The method of claim 1 , wherein the persistent resource allocation is configured to carry a Hybrid Automatic Repeat Request (HARQ) packet stream, further comprising:
detecting a series of failed HARQ packet transfers; and
retransmitting at least a portion of the persistent allocation information element.
7. A method of persistent resource allocation, the method comprising:
communicating a persistent resource allocation information element;
receiving a negative acknowledgment (NACK) indication on a shared NACK channel; and
retransmitting at least a portion of the persistent resource allocation information element to at least one of a group of client stations 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 negative acknowledgment (NACK) over a shared 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 at least one persistent allocation.
10. The method of claim 8 further comprising:
receiving a second persistent allocation information element indicating that an error condition was detected and no changes were made; and
continuing operation according to a previously received persistent allocation information element.
11. The method of claim 8 further comprising:
receiving a second persistent allocation information element indicating that an error condition was detected and a set of changes made to a previously received persistent; and
continuing operation according to the set of changes applied to the previously received persistent allocation information element.
12. A base station comprising:
a scheduler configured to schedule a candidate client station for persistent resource allocation;
an information element (IE generator configured to:
associate the candidate client station with a dedicated affirmative acknowledgment (ACK) channel and a shared negative acknowledgment (NACK) channel; and
configure a persistent allocation information element indicating the persistent resource allocation, the dedicated ACK channel, and the shared NACK channel; and
a transmitter configured to transmit the persistent allocation information element.
13. The base station of claim 12 further comprising configuring the IE generator to use a pseudo random code to define the shared NACK channel indicated in the persistent allocation information element.
14. The base station of claim 12 further comprising:
a receiver configured to:
receive a NACK indication over the shared NACK channel;
receive an ACK indication over the dedicated ACK channel; and
detect an energy level from the candidate client station; and
an ACK/NACK module configured to determine an error condition based on at least one of:
receiving, by the receiver, the NACK indication over the shared NACK channel;
detecting, by the receiver, little or no energy from the candidate client station on the persistent resource allocation; and
missing, by the receiver, the ACK indication over the dedicated ACK channel.
15. The base station of claim 14 further comprising:
the IE generator configured to determine, based on the error condition determined by the ACK/NACK module and based on changes made to persistent allocation corresponding to one or more client station of a group of client stations associated with the shared NACK channel, a set of recent changes; and
the transmitter configured to transmit an indication of the set of recent changes made to persistent allocations corresponding to at least one of the group of client stations associated with the shared NACK channel, wherein a no-changes-made indication is transmitted if the set of recent changes is empty.
16. The base station of claim 14 , further comprising:
the transmitter configured to transmit at least a portion of the persistent allocation information element.
17. A base station comprising:
a transmitter configured to communicate a persistent resource allocation information element; and
a receiver configured to receive a negative acknowledgment (NACK) indication on a shared NACK channel;
wherein the transmitter is configured, on a condition that the NACK indication is received, to retransmit at least a portion of the persistent resource allocation information element to at least one of a group of client stations associated with the shared NACK channel.