Transmit power control for uplink transmissions

A non-transitory computer-readable storage medium that stores instructions for execution by one or more processors, the instructions to configure the one or more processors to cause an apparatus of a high-efficiency (HE) station (STA) to:

• decode a trigger frame comprising a received signal strength indicator (RSSI) subfield, the received RSSI subfield indicating a desired received signal power of a HE trigger-based Physical Layer Convergence Protocol (PLCP) Protocol Data Unit (PPDU) response, the trigger frame further comprising a modulation and coding scheme (MCS) subfield for the HE trigger-based PPDU response and an access point (AP) transmit power subfield indicating a transmit power level used by the HE AP to transmit the trigger frame;
• determine a path loss based on the AP transmit power level and a measured received signal strength of the trigger frame;
• determine a transmit power (TxP) to use to transmit the HE trigger-based PPDU response based on the determined path loss and a value of the goal RSSI subfield;
• determine an uplink power headroom indicating an amount of headroom above the TxP available to the HE STA to transmit the HE trigger-based PPDU response;
• and
• encode the HE trigger-based PPDU response in accordance with a value of the MCS subfield and the HE trigger-based PPDU response to comprise a subfield indicating the uplink power headroom.

A method performed by an apparatus of an high-efficiency (HE) station (STA), the method comprising:

• decoding a trigger frame comprising a received signal strength indicator (RSSI) subfield, the RSSI subfield indicating a desired received signal power of a HE trigger-based Physical Layer Convergence Protocol (PLCP) Protocol Data Unit (PPDU) response, the trigger frame further comprising a modulation and coding scheme (MCS) subfield for the HE trigger-based PPDU response and an access point (AP) transmit power subfield indicating a transmit power level used by the HE AP to transmit the trigger frame;
• determining a path loss based on the AP transmit power level and a measured received signal strength of the trigger frame;
• determining a transmit power (TxP) to use to transmit the HE trigger-based PPDU response based on the determined path loss and a value of the RSSI subfield;
• determining an uplink power headroom indicating an amount of headroom above the TxP available to the HE STA to transmit the HE trigger-based PPDU response;
• and
• encoding the HE trigger-based PPDU response in accordance with a value of the MCS subfield and the HE trigger-based PPDU response to comprise a subfield indicating the uplink power headroom.

An apparatus of high-efficiency (HE) access point (AP), the apparatus comprising:

• memory;
• and, processing circuitry coupled to the memory, the processing circuitry configured to:
• encode a trigger frame for a plurality of HE stations (STAs), the trigger frame comprising a received signal strength indicator (RSSI) field for each HE STA, each RSSI field indicating a desired received signal power at the HE AP of a HE trigger-based Physical Layer Convergence Protocol (PLCP) Protocol Data Unit (PPDU) response to be transmitted by each of the plurality of HE STAs in response to the trigger frame, the trigger frame further comprising a modulation and coding scheme (MCS) indicating a MCS to be used by each HE STA of the plurality of HE STAs to encode a corresponding HE trigger-based PPDU response, and further encode the trigger frame to comprise a first transmit power (TxP) to be used to transmit the trigger frame;
• and
• decode a plurality of HE trigger-based PPDU responses in accordance with a corresponding MCS, each HE trigger-based PPDU response comprising a headroom indicating a number of decibels (dBs) above a corresponding second TxP used by a corresponding HE STA to transmit a corresponding HE trigger-based PPDU that is available to the corresponding HE STA to transmit the corresponding HE trigger-based PPDU for the corresponding MCS.