Power headroom report method and apparatus of UE
View Patent ↗The present disclosure relates to a communication method and system for converging a 5th-Generation (5G) communication system for supporting higher data rates beyond a 4th-Generation (4G) system with a technology for Internet of Things (IoT). The present disclosure may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. An improved method and an apparatus for reporting Power Headroom (PH) of a UE are provided. The Power Headroom Report (PHR) method of the present invention includes determining whether to trigger PHR based on a change of Power Management Maximum Power Reduction (P-MPR) between two time points, generating, if PHR is determined to be triggered, Power Headroom, and reporting the Power Headroom information to a base station.
1. A method for reporting a power headroom (PH) by a terminal in a wireless communication system, the method comprising:
transmitting a first power headroom report (PHR) based on a first uplink resource allocated to a serving cell;
determining whether a second uplink resource is allocated to the serving cell;
identifying whether power backoff due to power management has changed more than a threshold since a transmission of the first PHR, in case that the second uplink resource is allocated to the serving cell; and
transmitting, to a base station, a second PHR based on the second uplink resource, in case that the power backoff due to the power management has changed more than the threshold since the transmission of the first PHR,
wherein the second PHR is transmitted based on a first type PHR of the first type PHR and a second type PHR, and
wherein the first type PHR includes the PH for each of at least one serving cell and bitmap information indicating a serving cell for which the PH is to be reported.
2. The method of claim 1 ,
wherein the first type PHR includes a first field for indicating whether or not the power backoff due to the power management is applied, and
wherein the first field corresponds to a first bit of an octet including the PH in the first type PHR.
3. The method of claim 2 ,
wherein the first field is set to 1 in case that the power backoff due to the power management is applied, and
wherein the first field is set to 0 in case that the power backoff due to the power management is not applied.
4. The method of claim 2 , wherein the first type PHR further includes a second field for indicating whether a PH value corresponding to the PH is based on a real transmission.
5. The method of claim 4 , wherein the second field is set to 0 in case that the PH value is based on the real transmission.
6. The method of claim 1 , further comprising calculating uplink transmit power before transmitting the second PHR,
wherein the calculating of the uplink transmit power comprises determining a minimum value between a maximum transmit power and a required transmit power as the uplink transmit power,
wherein the required transmit power is calculated based on at least one of a number of transmission resource blocks, a transmission format, or a pathloss, and
wherein the maximum transmit power is a value selected between an upper bound (P CMAX _ H ) and a lower bound (P CMAX _ L ) that are determined by following equations:
P CMAX _ L =MIN{ P EMAX −T C ,P PowerClass −MAX( MPR+A - MPR,P - MPR )− T C },
P CMAX _ H =MIN{ P EMAX ,P PowerClass }
where P EMAX is a maximum allowed terminal output power provided by the base station, P PowerClass is a maximum available terminal power, ΔT C is a parameter for allowing additional transmission power relaxation when uplink transmission is performed at an edge of a frequency band.
7. A terminal for reporting a power headroom (PH) in a wireless communication system, the terminal comprising:
a transceiver; and
a controller coupled with the transceiver and configured to control to:
transmit a first power headroom report (PHR) based on a first uplink resource allocated to a serving cell;
determine whether a second uplink resource is allocated to the serving cell;
identify whether power backoff due to power management has changed more than a threshold since a transmission of the first PHR, in case that the second uplink resource is allocated to the serving cell; and
transmit, to a base station, a second PHR based on the second uplink resource, in case that the power backoff due to the power management has changed more than the threshold since the transmission of the first PHR,
wherein the second PHR is transmitted based on a first type PHR of the first type PHR and a second type PHR, and
wherein the first type PHR includes the PH for each of at least one serving cell and bitmap information indicating a serving cell for which the PH is to be reported.
8. The terminal of claim 7 ,
wherein the first type PHR includes a first field for indicating whether or not the power backoff due to the power management is applied, and
wherein the first field corresponds to a first bit of an octet including the PH in the first type PHR.
9. The terminal of claim 8 ,
wherein the first field is set to 1 in case that the power backoff due to the power management is applied, and
wherein the first field is set to 0 in case that the power backoff due to the power management is not applied.
10. The terminal of claim 8 , wherein the first type PHR further includes a second field for indicating whether a PH value corresponding to the PH is based on a real transmission.
11. The terminal of claim 10 , wherein the second field is set to 0 in case that the PH value is based on the real transmission.
12. The terminal of claim 7 ,
wherein the controller is further configured to:
calculate uplink transmit power before transmitting the second PHR, and
determine a minimum value between a maximum transmit power and a required transmit power as the uplink transmit power,
wherein the required transmit power is calculated based on at least one of a number of transmission resource blocks, a transmission format, or a pathloss, and
wherein the maximum transmit power is a value selected between an upper bound (P CMAX _ H ) and a lower bound (P CMAX _ L ) that are determined by following equations:
P CMAX _ L =MIN{ P EMAX −T C ,P PowerClass −MAX( MPR+A - MPR,P - MPR )− T C },
P CMAX _ H =MIN{ P EMAX ,P PowerClass }
where P EMAX is a maximum allowed terminal output power provided by the base station, P PowerClass is a maximum available terminal power, ΔT C is a parameter for allowing additional transmission power relaxation when uplink transmission is performed at an edge of a frequency band.
13. A method for receiving a power headroom (PH) by a base station in a wireless communication system, the method comprising:
receiving, from a terminal, a first power headroom report (PHR) based on a first uplink resource allocated to a serving cell; and
receiving, from the terminal, a second PHR based on a second uplink resource allocated to the serving cell, in case that power backoff due to power management of the terminal has changed more than a threshold since the transmission of the first PHR,
wherein it is identified by the terminal whether the power backoff due to the power management has changed more than the threshold since the transmission of the first PHR,
wherein the second PHR is received based on a first type PHR of the first type PHR and a second type PHR, and
wherein the first type PHR includes the PH for each of at least one serving cell and bitmap information indicating a serving cell for which the PH is to be reported.
14. The method of claim 13 ,
wherein the first type PHR includes a first field for indicating whether or not the power backoff due to the power management is applied, and
wherein the first field corresponds to a first bit of an octet including the PH in the first type PHR.
15. The method of claim 14 ,
wherein the first field is set to 1 in case that the power backoff due to the power management is applied, and
wherein the first field is set to 0 in case that the power backoff due to the power management is not applied.
16. The method of claim 14 , wherein the first type PHR further includes a second field for indicating whether a PH value corresponding to the PH is based on a real transmission.
17. The method of claim 16 , wherein the second field is set to 0 in case that the PH value is based on the real transmission.
18. A base station for receiving a power headroom (PH) in a wireless communication system, the base station comprising:
a transceiver; and
a controller coupled with the transceiver and configured to control to:
receive, from a terminal, a first power headroom report (PHR) based on a first uplink resource allocated to a serving cell, and
receive, from the terminal, a second PHR based on a second uplink resource allocated to the serving cell, in case that power backoff due to power management of the terminal has changed more than a threshold since the transmission of the first PHR,
wherein it is identified by the terminal whether the power backoff due to the power management has changed more than the threshold since the transmission of the first PHR,
wherein the second PHR is received based on a first type PHR of the first type PHR and a second type PHR, and
wherein the first type PHR includes the PH for each of at least one serving cell and bitmap information indicating a serving cell for which the PH is to be reported.
19. The base station of claim 18 ,
wherein the first type PHR includes a first field for indicating whether or not the power backoff due to the power management is applied, and
wherein the first field corresponds to a first bit of an octet including the PH in the first type PHR.
20. The base station of claim 19 ,
wherein the first field is set to 1 in case that the power backoff due to the power management is applied, and
wherein the first field is set to 0 in case that the power backoff due to the power management is not applied.
21. The base station of claim 19 , wherein the first type PHR further includes a second field for indicating whether a PH value corresponding to the PH is based on a real transmission.
22. The base station of claim 21 , wherein the second field is set to 0 in case that the PH value is based on the real transmission.