# US 11,122,517 B2 · Multi-user power control methods and procedures

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- Number: US 11,122,517 B2
- Document ID: US11122517B2
- Status: Granted
- Kind: B2
- Application number: 16/700,737
- Filed: 2019-12-02
- Published: 2020-04-02
- Granted: 2021-09-14
- Earliest claimed: 2015-09-10
- Assignees: InterDigital Patent Holdings, Inc.
- Applicants: InterDigital Patent Holdings, Inc.
- Inventors: Hanqing Lou; Oghenekome Oteri; Guodong Zhang; Robert L. Olesen; Rui Yang
- Web page: https://patentgrep.com/patent/US11122517B2

## CPC

- H04W 52/146: {Uplink power control}
- H04W 52/10: Open loop power control
- H04W 52/242: {taking into account path loss}
- H04W 52/245: {taking into account received signal strength}
- H04W 52/246: {where the output power of a terminal is based on a path parameter calculated in said terminal}
- H04W 74/006: {in the downlink, i.e. towards the terminal}
- H04W 52/228: {using past power values or information}
- H04W 52/241: {taking into account channel quality metrics, e.g. SIR, SNR, CIR or Eb/lo}
- H04W 84/12: WLAN [Wireless Local Area Networks]
- H04W 88/02: Terminal devices
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)

## Abstract

Methods and systems for operation in a WLAN are provided. Methods and systems for a transmit power control (TPC) scheme are disclosed. In an embodiment, an access point (AP) may send a trigger frame to one or more stations (STAs) for synchronizing and scheduling uplink (UL) multi-user (MU) transmissions. The trigger frame may contain an open-loop power control index 1 and a power adjustment index 2. The one or more STAs may estimate pathloss using an indicated AP transmit power and received power to set a baseline transmit power. The one or more STAs may adjust their transmit power in the UL transmission period to be the indicated target receive power at the AP.

## Claims

### Claim 1

A station (STA) comprising:
an antenna; and
a processor operatively coupled to the antenna;
the processor and the antenna configured to receive, from an access point (AP), a downlink (DL) frame, the DL frame comprising, in a medium access control (MAC) header, an indication of a transmit power that the AP used to transmit the DL frame, an indication of a first target receive signal power at the AP of a signal associated with the STA, wherein the DL frame is a DL multi-user physical layer convergence protocol (PLCP) protocol data unit (PPDU) MU-PPDU and the DL frame triggers an uplink (UL) multi-user (MU) transmission opportunity;
the processor and the antenna further configured to measure a received power of the DL frame;
the processor configured to calculate a downlink pathloss of the DL frame based on the transmit power of the DL frame that the AP used to transmit the DL frame and the measured received power of the DL frame;
the processor further configured to determine a STA transmit power based on the downlink pathloss and the first target receive signal power at the AP; and
the processor and the antenna further configured to send, to the AP, an uplink (UL) frame using the determined STA transmit power.

### Claim 2 (depends on 1)

The STA of claim 1, wherein the DL frame is a trigger frame.

### Claim 3 (depends on 1)

The STA of claim 1, wherein the processor and the antenna are configured to receive the DL frame and to send the UL frame during a first transmission opportunity (TXOP).

### Claim 4 (depends on 1)

The STA of claim 1, wherein the DL frame is one of a plurality of DL MU-PPDUs transmitted simultaneously by the AP to a corresponding plurality of STAs.

### Claim 5 (depends on 1)

The STA of claim 1, wherein:
the processor and the antenna are further configured to receive, from the AP, a separate trigger frame.

### Claim 6 (depends on 1)

The STA of claim 1, wherein the processor and the antenna are configured to send the UL frame as part of an UL multi-user (MU) transmission.

### Claim 7 (depends on 1)

The STA of claim 1, wherein the UL frame includes an UL PPDU or an UL acknowledgement (ACK)/block ACK (BA).

### Claim 8 (depends on 1)

The STA of claim 1, wherein the STA is configured as a non-AP STA.

### Claim 9

A method for use in a station (STA), the method comprising:
receiving, from an access point (AP), a downlink (DL) frame, the DL frame comprising, in a medium access control (MAC) header, an indication of a transmit power that the AP used to transmit the DL frame, an indication of a first target receive signal power at the AP of a signal associated with the STA, wherein the DL frame is a DL multi-user physical layer convergence protocol (PLCP) protocol data unit (PPDU) MU-PPDU and the DL frame triggers an uplink (UL) multi-user (MU) transmission opportunity;
measuring a received power of the DL frame;
calculating a downlink pathloss of the DL frame based on the transmit power of the DL frame that the AP used to transmit the DL frame and the measured received power of the DL frame;
determining a STA transmit power based on the downlink pathloss and the first target receive signal power at the AP of a signal associated with the STA; and
sending, to the AP, an UL frame using the determined STA transmit power.

### Claim 10 (depends on 9)

The method of claim 9, wherein the DL frame is a trigger frame.

### Claim 11 (depends on 9)

The method of claim 9, wherein the DL frame is received and the UL frame is sent during a first transmission opportunity (TXOP).

### Claim 12 (depends on 9)

The method of claim 9, wherein the DL frame is one of a plurality of DL MU-PPDUs transmitted simultaneously by the AP to a corresponding plurality of STAs.

### Claim 13 (depends on 9)

The method of claim 9, further comprising:
receiving, from the AP, a separate trigger frame.

### Claim 14 (depends on 9)

The method of claim 9, wherein the UL frame is sent as part of an UL multi-user (MU) transmission.

### Claim 15 (depends on 9)

The method of claim 9, wherein the UL frame includes an UL PPDU or an UL acknowledgement (ACK)/block ACK (BA).

### Claim 16 (depends on 9)

The method of claim 9, wherein the STA is a non-AP STA.