Wireless communication terminal and power control method

Patent metadata

Field	Value
Publication number	US-9326258-B2
Application number	US-201113995262-A
Country	US
Kind code	B2
Filing date	Dec 22, 2011
Priority date	Jan 7, 2011
Publication date	Apr 26, 2016
Grant date	Apr 26, 2016

Abstract

Provided is a wireless communication terminal which, when SRSs are simultaneously transmitted between CCs and between antenna ports, avoids increasing the effect of bit rounding errors of D/A converters when the number of antenna ports set for SRS transmission differs between CCs. This device comprises a transmission power calculation unit ( 107 ) which calculates the transmission power of a plurality of UL channels of a plurality of CCs and a plurality of antenna ports. A power scaling detection unit ( 108 ) detects whether or not the total transmission power of the UL channels exceeds the maximum transmission power specific to a UE. When power scaling is generated, a power scaling control unit ( 109 ) uses antenna port setting information set for SRS transmission between CCs to perform power scaling in such a way that all scaling weights are uniform between CCs, or between CCs and between antenna ports.

First claim

The invention claimed is:

1. A radio communication terminal apparatus comprising:
a transmission power calculating section that calculates transmission power of a plurality of uplink channels on a plurality of component carriers of carrier aggregation, and a plurality of antenna ports;
a power scaling detecting section that detects whether or not power scaling occurs, by detecting, using the calculated transmission power, whether or not a total value of the transmission power of uplink channels transmitted using the plurality of component carriers and the plurality of antenna ports exceeds maximum transmission power specific to the apparatus; and
a power scaling controlling section that performs power scaling when the power scaling detecting section has detected that power scaling occurs, and also when a plurality of reference signals are to be transmitted using antenna ports configured for transmission of reference signals on component carriers, the power scaling being performed in such a way that a total scaling weight considering scaling weights for multiple-antenna transmission becomes equal between the component carriers, or between the component carriers and between the antenna ports, on a basis of the number of antenna ports, or antenna port positions, or antenna port numbers configured for transmission of reference signals on the component carriers; wherein,
in the power scaling controlling section, a first scaling weight is equal to 1/A, where A is the number of reference signals to be transmitted using component carriers and antenna ports, the first scaling weight being used among the antenna ports, and the component carriers and the antenna ports being configured for transmission of reference signals.

2. The radio communication terminal apparatus according to claim 1 , wherein the power scaling controlling section applies a total scaling weight to power scaling of all reference signals, the total scaling weight being calculated by multiplying a second scaling weight by the first scaling weight, the second scaling weight being used among the component carriers.

3. A radio communication terminal apparatus comprising:
a transmission power calculating section that calculates transmission power of a plurality of uplink channels on a plurality of component carriers of carrier aggregation, and a plurality of antenna ports;
a power scaling detecting section that detects whether or not power scaling occurs, by detecting, using the calculated transmission power, whether or not a total value of the transmission power of uplink channels transmitted using the plurality of component carriers and the plurality of antenna ports exceeds maximum transmission power specific to the apparatus; and
a power scaling controlling section that performs power scaling when the power scaling detecting section has detected that power scaling occurs, and also when a plurality of reference signals are to be transmitted using antenna ports configured for transmission of reference signals on component carriers, the power scaling being performed in such a way that a total scaling weight considering scaling weights for multiple-antenna transmission becomes equal between the component carriers, or between the component carriers and between the antenna ports, on a basis of the number of antenna ports, or antenna port positions, or antenna port numbers configured for transmission of reference signals on the component carriers, wherein
the power scaling controlling section performs power scaling by applying an equal total scaling weight considering scaling weights for multiple-antenna transmission only with respect to antenna ports or antenna port numbers, or physical antennas simultaneously transmitting reference signals SRS, wherein,
in the power scaling controlling section, a first scaling weight is equal to 1/A, where A is the number of reference signals to be transmitted using the antenna ports or the physical antennas simultaneously transmitting the reference signals SRS, the first scaling weight being used among the antenna ports.

4. A power control method comprising:
calculating transmission power of a plurality of uplink channels on a plurality of component carriers of carrier aggregation, and a plurality of antenna ports;
detecting whether or not power scaling occurs, by detecting, using the calculated transmission power, whether or not a total value of the transmission power of uplink channels transmitted using the plurality of component carriers and the plurality of antenna ports exceeds maximum transmission power specific to an apparatus transmitting the UL channels; and
performing power scaling when it has been detected that power scaling occurs, and also when a plurality of reference signals are to be transmitted using antenna ports configured for transmission of reference signals on component carriers, the power scaling being performed in such a way that a total scaling weight considering scaling weights for multiple-antenna transmission becomes equal between the component carriers, or between the component carriers and between the antenna ports, on a basis of the number of antenna ports, or antenna port positions, or antenna port numbers configured for transmission of reference signals on the component carriers, wherein,
in the performing the power scaling, a first scaling weight is equal to 1/A, where A is the number of reference signals to be transmitted using component carriers and antenna ports, the first scaling weight being used among the antenna ports, and the component carriers and the antenna ports being configured for transmission of reference signals.

5. A power control method comprising:
calculating transmission power of a plurality of uplink channels on a plurality of component carriers of carrier aggregation, and a plurality of antenna ports;
detecting whether or not power scaling occurs, by detecting, using the calculated transmission power, whether or not a total value of the transmission power of uplink channels transmitted using the plurality of component carriers and the plurality of antenna ports exceeds maximum transmission power specific to an apparatus transmitting the UL channels; and
performing power scaling when it has been detected that power scaling occurs, and also when a plurality of reference signals are to be transmitted using antenna ports configured for transmission of reference signals on component carriers, the power scaling being performed in such a way that a total scaling weight considering scaling weights for multiple-antenna transmission becomes equal between the component carriers, or between the component carriers and between the antenna ports, on a basis of the number of antenna ports, or antenna port positions, or antenna port numbers configured for transmission of reference signals on the component carriers; wherein
the power scaling is performed by applying an equal total scaling weight considering scaling weights for multiple-antenna transmission only with respect to antenna ports or antenna port numbers, or physical antennas simultaneously transmitting reference signals SRS, wherein,
in the performing the power scaling, a first scaling weight is equal to 1/A, where A is the number of reference signals to be transmitted using the antenna ports or the physical antennas simultaneously transmitting the reference signals SRS, the first scaling weight being used among the antenna ports.

Assignees

• Takaoka Shinsuke
• Imamura Daichi
• Hoshino Masayuki
• Iwai Takashi
• Nishio Akihiko
• Panasonic Ip Corp America

Inventors

• Takaoka Shinsuke
• Imamura Daichi
• Hoshino Masayuki
• Iwai Takashi
• Nishio Akihiko

Classifications

• H04W52/146

  Uplink power control · CPC title

• H04W52/367

  Power values between minimum and maximum limits, e.g. dynamic range · CPC title

• H04W52/34

  TPC management, i.e. sharing limited amount of power among users or channels or data types, e.g. cell loading · CPC title

• H04W52/346

  distributing total power among users or channels · CPC title

• H04W52/42 Primary

  in systems with time, space, frequency or polarisation diversity · CPC title