# US 2019/0246361 A1 · Uplink power headroom reporting for carrier aggregation

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- Number: US 2019/0246361 A1
- Document ID: US20190246361A1
- Status: Published application
- Kind: A1
- Application number: 16/388,117
- Filed: 2019-04-18
- Published: 2019-08-08
- Earliest claimed: 2008-12-03
- Assignees: InterDigital Patent Holdings, Inc.
- Applicants: InterDigital Patent Holdings, Inc.
- Inventors: Guodong Zhang; Erdem Bala; Philip J. Pietraski; Sung-Hyuk Shin; Kyle Jung-Lin Pan; Joseph S. Levy; Jin Wang; Peter S. Wang; Janet A. Stern-Berkowitz; John W. Haim
- Web page: https://patentgrep.com/patent/US20190246361A1

## CPC

- H04W 52/365: {Power headroom reporting}
- H04W 52/146: {Uplink power control}
- H04W 52/242: {taking into account path loss}
- H04W 52/346: {distributing total power among users or channels}
- H04W 52/367: {Power values between minimum and maximum limits, e.g. dynamic range}
- H04W 72/0453: Resources in frequency domain, e.g. a carrier in FDMA
- H04W 72/0473: {the resource being transmission power}
- H04W 72/21: in the uplink direction of a wireless link, i.e. towards the network
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)

## Abstract

A method for reporting power headroom is disclosed. Power headroom may be reported across all carriers (wideband), for a specific carrier, or for a carrier group. The formula used to calculate the power headroom depends on whether the carrier (or a carrier in the carrier group) has a valid uplink grant. If the carrier or carrier group does not have a valid uplink grant, the power headroom may be calculated based on a reference grant. The power headroom is calculated by a wireless transmit/receive unit and is reported to an eNodeB.

## Claims

### Claim at position 1

1-29. (canceled)

### Claim 30

A wireless transmit/receive unit (WTRU), the WTRU comprising:
a processor configured to:
determine a first carrier that does not have a physical uplink shared channel (PUSCH) transmission in a transmission occasion;
determine a maximum power for the first carrier;
calculate a power headroom for the first carrier using the maximum power for the first carrier and a reference grant; and
send a power headroom report, the power headroom report being sent on a PUSCH of a second carrier and comprising the power headroom for the first carrier.

### Claim 31 (depends on 30)

The WTRU of claim 30, wherein the reference grant is used for the power headroom calculation for the first carrier based on the first carrier not having a PUSCH transmission in the transmission occasion.

### Claim 32 (depends on 31)

The WTRU of claim 31, wherein the power headroom report comprises a power headroom for the second carrier.

### Claim 33 (depends on 32)

The WTRU of claim 32, wherein the power headroom is determined based on the power of the PUSCH transmission set for the second carrier.

### Claim 34 (depends on 30)

The WTRU of claim 30, wherein the transmission occasion comprises a subframe.

### Claim 35 (depends on 30)

The WTRU of claim 30, wherein the reference grant is based on a reference format.

### Claim 36 (depends on 35)

The WTRU of claim 35, wherein the reference format is a downlink control information (DCI) format.

### Claim 37 (depends on 30)

The WTRU of claim 30, wherein the power headroom report is a type 1 power headroom report.

### Claim 38 (depends on 30)

The WTRU of claim 30, wherein the reference grant is a pre-defined allocation.

### Claim 39 (depends on 30)

The WTRU of claim 30, wherein the reference grant is a pre-defined number of resource blocks.

### Claim 40

A method for calculating a power headroom via a wireless transmit/receive unit (WTRU), the method comprising:
determining a first carrier that does not have a physical uplink shared channel (PUSCH) transmission in a transmission occasion;
determining a maximum power for the first carrier;
calculating a power headroom for the first carrier using the maximum power for the first carrier and a reference grant; and
sending a power headroom report, the power headroom report being sent on a PUSCH of a second carrier and comprising the power headroom for the first carrier.

### Claim 41 (depends on 40)

The method of claim 40, wherein the reference grant is used for the power headroom calculation for the first carrier based on the first carrier not having a PUSCH transmission in the transmission occasion.

### Claim 42 (depends on 41)

The method of claim 41, wherein the power headroom report comprises a power headroom for the second carrier.

### Claim 43 (depends on 42)

The method of claim 42, wherein the power headroom is determined based on the power of the PUSCH transmission set for the second carrier.

### Claim 44 (depends on 40)

The method of claim 40, wherein the transmission occasion comprises a subframe.

### Claim 45 (depends on 40)

The method of claim 40, wherein the reference grant is based on a reference format.

### Claim 46 (depends on 45)

The method of claim 45, wherein the reference format is a downlink control information (DCI) format.

### Claim 47 (depends on 40)

The method of claim 40, wherein the power headroom report is a type 1 power headroom report.

### Claim 48 (depends on 40)

The method of claim 40, wherein the reference grant is a pre-defined allocation.

### Claim 49 (depends on 40)

The method of claim 40, wherein the reference grant is a pre-defined number of resource blocks.