Mechanism for maximizing uplink bandwidth by overlapping control regions in WiMAX systems
View Patent ↗A method and system for allocating a particular uplink control region to both HARQ ACKCH and CQICH in order to maximize uplink bandwidth for data transfer in a communication network. A control region scheduling (CRS) utility assigns a higher priority to HARQ ACKCH relative to CQICH. When both HARQ ACKCH and CQICH are to be allocated for a subscriber in the same region in the same frame, HARQ ACKCH is allocated in the region while CQICH is rejected. As the substitute to the rejected CQICH, the CRS utility may use current uplink channel quality information in combination with the corresponding HARQ ACK transmission to estimate the downlink channel quality information for the subscriber. Upon receiving the HARQ ACK information, the CRS utility updates the subscriber(s) uplink channel quality information. The CRS utility also provides a configurable option of activating or de-activating the sharing of the uplink control region.
1. A method for allocating a control region to a subscriber in a wireless communication system comprising:
assigning a higher priority to Hybrid Automatic Repeat Request Acknowledgement (HARQ) Acknowledgement Channel (ACKCH) relative to downlink Channel Quality Indicator Channel (CQICH);
allocating one of HARQ ACKCH and CQICH to a shared control region within a resource frame;
in response to an allocation of both HARQ ACKCH and CQICH to a same control region within a same resource frame, accepting only HARQ ACKCH within the control region as a result of an override of the CQICH, based on the higher relative priority, wherein the override occurs when a previous and un-expired set of CQICH information exists;
in response to a rejection of CQICH as a result of an override, estimating a downlink channel quality information for the subscriber based on a current set of uplink channel quality information; and
in response to a reception of the HARQ ACKCH information, updating the subscriber uplink channel quality information.
2. The method of claim 1 further comprising:
maintaining a location of the control region designated for HARQ ACKCH and CQICH for uplink sub-frames; and
providing a configurable option to activate and de-activate the sharing of the uplink control region for HARQ ACKCH and CQICH.
3. The method of claim 1 , wherein said estimating further comprises:
retrieving a mapping table of empirical data relating uplink and downlink channel information; and
generating downlink channel information from uplink channel information utilizing the mapping table.
4. The method of claim 1 , further comprising:
providing a scheduling offset, wherein said offset is appropriately determined to avoid multiple users reporting CQICH information in a same frame; and
assigning CQICH information to a frame based on the scheduling offset.
5. A base station comprising:
a processor;
a utility that allocates a control region to a subscriber when executed by the processor, the utility configured to:
assign a higher priority to Hybrid Automatic Repeat Request Acknowledgement (HARQ) Acknowledgement Channel (ACKCH) relative to downlink Channel Quality Indicator Channel (CQICH);
allocate one of HARQ ACKCH and CQICH to a shared control region within a resource frame;
in response to an allocation of both HARQ ACKCH and CQICH to a same control region within a same resource frame, accept only HARQ ACKCH within the control region as a result of an override of the CQICH, based on the higher relative priority, wherein said override occurs when a previous and un-expired set of CQICH information exists;
in response to a rejection of CQICH as a result of an override, estimate a downlink channel quality information for the subscriber based on a current set of uplink channel quality information; and
in response to a reception of the HARQ ACK information, update the subscriber uplink channel quality information.
6. The base station of claim 5 , wherein the utility further is configured to:
maintain a location of the control region designated for HARQ ACKCH and CQICH for uplink sub-frames; and
provide a configurable option to activate and de-activate the sharing of the uplink control region for HARQ ACKCH and CQICH.
7. The base station of claim 5 , wherein the utility is configured to estimate a downlink channel quality information for the subscriber by:
retrieving a mapping table of empirical data relating uplink and downlink channel information; and
generating downlink channel information from uplink channel information utilizing the mapping table.
8. The base station of claim 5 , wherein the utility further is configured to:
provide a scheduling offset, wherein the offset is appropriately determined to avoid multiple users reporting CQICH information in a same frame; and
assign CQICH information to a frame based on the scheduling offset.