User terminal, radio base station and inter-frequency measurement method
The present disclosure is designed to reduce the load of inter-frequency measurements in user terminals in a radio communication system in which a plurality of component carriers (CCs) are used in each small cell within a macro cell. The inter-frequency measurement method of the present disclosure includes the steps of, from a radio base station forming a macro cell to a user terminal, transmitting the transmission timing information of a detection signal in a small cell, and a timing shift value for detection signals of the plurality of CCs that transmitted with shifted timings in the small cell, and, in the user terminal, measuring the plurality of CCs in a measurement gap based on the transmission timing information and the timing shift value.
1. A user terminal in a radio communication system in which a plurality of component carriers (CCs) are used in a small cell within a macro cell, the user terminal comprising:
a receiver that receives, from a radio base station forming the macro cell, transmission timing information of a detection signal in the small cell, and a timing shift value for detection signals per CC of the plurality of CCs that are transmitted with shifted timings in the small cell; and
a processor that measures a total received power per CC of the plurality of CCs in a measurement gap, in which detection signals per CC of the plurality of CCs are either transmitted or not transmitted, based on the transmission timing information and the timing shift value.
2. The user terminal according to claim 1 , wherein the processor measures received power of the detection signals per CC of the plurality of CCs in the measurement gap, in which detection signals per CC of the plurality of CCs are transmitted.
3. The user terminal according to claim 2 , wherein:
the receiver receives measurement gap configuration information from the radio base station; and
the measurement gap is configured based on the measurement gap configuration information.
4. The user terminal according to claim 2 , wherein the measurement gap is shifted based on the timing shift value.
5. The user terminal according to claim 2 , wherein:
the small cell comprises a plurality of small cells; and
between the plurality of small cells, detection signals of a same CC are transmitted synchronously.
6. The use terminal according to claim 1 , wherein:
the receiver receives measurement gap configuration information from the radio base station; and
the measurement gap is configured based on the measurement gap configuration information.
7. The user terminal according to claim 1 , wherein the measurement gap is shifted based on the timing shift value.
8. The user terminal according to claim 1 , wherein:
the small cell comprises a plurality of small cells; and
between the plurality of small cells, detection signals of a same CC are transmitted synchronously.
9. The user terminal according to claim 8 , wherein at least one of the detection signals of the plurality of CCs is transmitted in each of the plurality of small cells.
10. The user terminal according to claim 1 , wherein:
the receiver receives measurement gap configuration information from the radio base station; and
the measurement gap is configured based on the measurement gap configuration information.
11. The user terminal according to claim 1 , wherein the measurement gap is shifted based on the timing shift value.
12. The user terminal according to claim 1 , wherein:
the small cell comprises a plurality of small cells; and
between the plurality of small cells, detection signals of a same CC are transmitted synchronously.
13. A radio base station that forms a macro cell in a radio communication system in which a plurality of component carriers (CCs) are used in a small cell within the macro cell, the radio base station comprising:
a processor that generates transmission timing information of a detection signal in the small cell, and a timing shift value for detection signals per CC of the plurality of CCs that are transmitted with shifted timings in the small cell; and
a transmitter that transmits the transmission timing information and the timing shift value to a user terminal,
wherein the total received power per CC of the plurality of CCs is measured in a measurement gap, in which detection signals per CC of the plurality of CCs are either transmitted or not transmitted, based on the transmission timing information and the timing shift value.
14. An inter-frequency measurement method in a radio communication system in which a plurality of component carriers (CCs) are used in a small cell within a macro cell, the inter-frequency measurement method comprising the steps of:
from a radio base station forming the macro cell to a user terminal, transmitting transmission timing information of a detection signal in the small cell, and a timing shift value for detection signals per CC of the plurality of CCs that are transmitted with shifted timings in the small cell; and
in the user terminal, measuring a total received power per CC of the plurality of CCs in a measurement gap, in which detection signals per CC of the plurality of CCs area either transmitted or not transmitted, based on the transmission timing information and the timing shift value.