Unified feedback for OFDMA WLAN
An access point (AP) may transmit a null data packet announcement (NDPA) with an indication of a resource unit of a bandwidth that feedback is requested. The AP may transmit a null data packet (NDP) for measurement of a channel quality for a resource unit of a bandwidth. The AP may transmit, based on a response, another feedback request for resource units of the bandwidth.
1 . A first station (STA) comprising a transceiver and a processor, the transceiver and the processor configured to:
receive a null data packet announcement (NDPA), the NDPA comprising a first STA information field and a second STA information field, wherein the first STA information field comprises:
a first subcarrier grouping,
a first AID subfield configured to include a first STA identifier (ID) identifying the first STA, and
at least a first subfield comprising a first resource unit (RU) start index for the first STA and a second subfield comprising a first RU end index for the first STA, wherein the first RU start index indicated in the first subfield and the first RU end index indicated in the second subfield indicates a first group of RUs comprising a first group of subcarriers associated with channel state feedback, wherein the first group of RUs for the first STA is less than a 20 megahertz (MHz) channel bandwidth;
and wherein the second STA information field comprises:
a second subcarrier grouping,
a second AID subfield configured to include a second STA ID identifying a second STA, and
at least a third subfield comprising a second RU start index for the second STA and a fourth subfield comprising a second RU end index for the second STA, wherein the second RU start index indicated in the third subfield and the second RU end index indicated in the fourth subfield indicates a second group of RUs comprising a second group of subcarriers associated with channel state feedback, wherein the second group of RUs for the second STA is less than a 20 MHz channel bandwidth;
receive a null data packet (NDP) for measurement of a channel quality;
receive, subsequent to the NDP, a trigger frame that specifies a resource allocation for feedback responses from each of the first STA and the second STA, wherein the resource allocation for the feedback responses from each of first STA and the second STA is different;
determine the channel state feedback based on an identifier in the trigger frame corresponding to the first STA ID; and
transmit the feedback response utilizing the resource allocation for the first STA in response to the trigger frame short a interframe spacing (SIFS) after the trigger frame, wherein the feedback response comprises signal to noise ratio (SNR) information.
2 . The STA of claim 1 , wherein the feedback response comprises per-RU feedback that is associated with a subset range of the first group of RUs comprising the first group of subcarriers.
3 . The STA of claim 1 , wherein the feedback response is provided in terms of a signal to noise ratio (SNR).
4 . The STA of claim 1 , wherein the feedback response comprises a per-RU average signal to noise ratio (SNR) of each space time stream associated with the first group of RUs.
5 . The STA of claim 1 , wherein the second group of subcarriers is different than the first group of subcarriers.
6 . A method performed by a first station (STA), the method comprising:
receiving a null data packet announcement (NDPA), the NDPA comprising a first STA information field and a second STA information field, wherein the first STA information field comprises:
a first subcarrier grouping,
a first AID subfield configured to include a first STA identifier (ID) identifying the first STA, and
at least a first subfield comprising a first resource unit (RU) start index for the first STA and a second subfield comprising a first RU end index for the first STA, wherein the first RU start index indicated in the first subfield and the first RU end index indicated in the second subfield indicates a first group of RUs comprising a first group of subcarriers associated with channel state feedback, wherein the first group of RUs for the first STA is less than a 20 megahertz (MHz) channel bandwidth;
and wherein the second STA information field comprises:
a second subcarrier grouping,
a second AID subfield configured to include a second STA ID identifying a second STA, and
at least a third subfield comprising a second RU start index for the second STA and a fourth subfield comprising a second RU end index for the second STA, wherein the second RU start index indicated in the third subfield and the second RU end index indicated in the fourth subfield indicates a second group of RUs comprising a second group of subcarriers associated with channel state feedback, wherein the second group of RUs for the second STA is less than a 20 MHz channel bandwidth;
receiving a null data packet (NDP) for measurement of a channel quality;
receiving, subsequent to the NDP, a trigger frame that specifies a resource allocation for feedback responses from each of the first STA and the second STA, wherein the resource allocation for the feedback responses from each of first STA and the second STA is different;
determining the channel state feedback based on an identifier in the trigger frame corresponding to the first STA ID; and
transmitting the feedback response utilizing the resource allocation for the first STA in response to the trigger frame a short interframe spacing (SIFS) after the trigger frame, wherein the feedback response comprises signal to noise ratio (SNR) information.
7 . The method of claim 6 , wherein the feedback responses comprises per-RU feedback that is associated with a subset range of the first group of RUs comprising the first group of subcarriers.
8 . The method of claim 6 , wherein the feedback response is provided in terms of a signal to noise ratio (SNR).
9 . The method of claim 6 , wherein the feedback response comprises a per-RU average signal to noise ratio (SNR) of each space time stream associated with the first group of RUs.
10 . The method of claim 6 , wherein the second group of subcarriers is different than the first group of subcarriers.
11 . An access point (AP) comprising a transceiver and a processor, the transceiver and the processor configured to:
send a null data packet announcement (NDPA), the NDPA comprising a first STA information field and a second STA information field, wherein the first STA information field comprises:
a first subcarrier grouping,
a first AID subfield configured to include a first STA identifier (ID) identifying the first STA, and
at least a first subfield comprising a first resource unit (RU) start index for the first STA and a second subfield comprising a first RU end index for the first STA, wherein the first RU start index indicated in the first subfield and the first RU end index indicated in the second subfield indicates a first group of RUs comprising a first group of subcarriers associated with channel state feedback, wherein the first group of RUs for the first STA is less than a 20 megahertz (MHz) channel bandwidth;
and wherein the second STA information field comprises:
a second subcarrier grouping,
a second AID subfield configured to include a second STA ID identifying a second STA, and
at least a third subfield comprising a second RU start index for the second STA and a fourth subfield comprising a second RU end index for the second STA, wherein the second RU start index indicated in the third subfield and the second RU end index indicated in the fourth subfield indicates a second group of RUs comprising a second group of subcarriers associated with channel state feedback, wherein the second group of RUs for the second STA is less than a 20 MHz channel bandwidth;
send a null data packet (NDP) for measurement of a channel quality;
send, subsequent to the NDP, a trigger frame that specifies a resource allocation for feedback responses from each of the first STA and the second STA, wherein the resource allocation for the feedback responses from each of first STA and the second STA is different; and
receive the feedback response utilizing the resource allocation for the first STA in response to the trigger frame a short interframe spacing (SIFS) after the trigger frame, wherein the feedback response comprises signal to noise ratio (SNR) information.
12 . The AP of claim 11 , wherein the feedback response comprises per-RU feedback that is associated with a subset range of the first group of RUs comprising the first group of subcarriers.
13 . The AP of claim 11 , wherein the feedback response is provided in terms of a signal to noise ratio (SNR).
14 . The AP of claim 11 , wherein the feedback response comprises a per-RU average signal to noise ratio (SNR) of each space time stream associated with the first group of RUs.
15 . The AP of claim 11 , wherein the second group of subcarriers is different than the first group of subcarriers.
16 . A method performed by an access point (AP), the method comprising:
sending a null data packet announcement (NDPA), the NDPA comprising a first STA information field and a second STA information field, wherein the first STA information field comprises:
a first subcarrier grouping,
a first AID subfield configured to include a first STA identifier (ID) identifying the first STA, and
at least a first subfield comprising a first resource unit (RU) start index for the first STA and a second subfield comprising a first RU end index for the first STA, wherein the first RU start index indicated in the first subfield and the first RU end index indicated in the second subfield indicates a first group of RUs comprising a first group of subcarriers associated with channel state feedback, wherein the first group of RUs for the first STA is less than a 20 megahertz (MHz) channel;
and wherein the second STA information field comprises:
a second subcarrier grouping,
a second AID subfield configured to include a second STA ID identifying a second STA, and
at least a third subfield comprising a second RU start index for the second STA and a fourth subfield comprising a second RU end index for the second STA, wherein the second RU start index indicated in the third subfield and the second RU end index indicated in the fourth subfield indicates a second group of RUs comprising a second group of subcarriers associated with channel state feedback, wherein the second group of RUs for the second STA is less than a 20 MHz channel bandwidth;
sending a null data packet (NDP) for measurement of a channel quality;
sending, subsequent to the NDP, a trigger frame that specifies a resource allocation for feedback responses from each of the first STA and the second STA, wherein the resource allocation for the feedback responses from each of first STA and the second STA is different; and
receiving the feedback response utilizing the resource allocation for the first STA in response to the trigger frame a short interframe spacing (SIFS) after the trigger frame, wherein the feedback response comprises signal to noise ratio (SNR) information.
17 . The method of claim 16 , wherein the feedback response comprises per-RU feedback that is associated with a subset range of the first group of RUs comprising the first group of subcarriers.
18 . The method of claim 16 , wherein the feedback response is provided in terms of a signal to noise ratio (SNR).
19 . The method of claim 16 , wherein the feedback response comprises a per-RU average signal to noise ratio (SNR) of each space time stream associated with the first group of RUs.
20 . The method of claim 16 , wherein the second group of subcarriers is different than the first group of subcarriers.