Radio communication method, radio base station and radio communication system
AssigneeNtt Docomo, Inc.
InventorsAnass Benjebbour, Yoshihisa Kishiyama
Life of this patent
Estimating the term…
Abstract
A radio communication method is provided in which beam forming information for forming transmission beams directed from the small base station to the user terminal are generated based on position-related information of the user terminal acquired by communication between the macro base station and the user terminal using a coverage carrier and position-related information of the small base station, and the small base station precodes at least one of a common control signal and a reference signal that are common in a small cell (C2) based on the beam forming information and transmits the precoded signal from a plurality of transmitting antennas using a capacity carrier.
Claims14
A radio communication method to allow a user terminal that communicates with a macro base station forming a macro cell, using a first carrier, to communicate with a small base station forming a small cell that is smaller than the macro cell, using a second carrier of a higher frequency band than the first carrier, the radio communication method comprising the steps of:
- generating beam forming information for forming a transmission beam directed from the small base station to the user terminal, based on position-related information of the user terminal acquired by communication between the macro base station and the user terminal using the first carrier;
- and
- in the small base station, precoding at least one of a common control signal and a reference signal that are common in the small cell, based on the beam forming information, and transmitting the precoded signal from a plurality of transmitting antennas using the second carrier.
A radio base station, which forms a small cell that is smaller than a macro cell, and which communicates with a user terminal using a second carrier of a higher frequency band than a first carrier, which the user terminal uses to communicate with a macro base station forming the macro cell, the radio base station comprising:
- a precoding section configured to precode at least one of a common control signal and a reference signal that are common in the small cell, based on beam forming information for forming a transmission beam directed to the user terminal;
- and
- a plurality of transmitting antennas configured to transmit at least one of the precoded common control signal and the precoded reference signal using the second carrier,
- wherein the beam forming information is generated based on position-related information of the user terminal acquired by communication between the macro base station and the user terminal using the first carrier.
A radio base station which communicates with a user terminal using a first carrier, and which connects with a small base station which communicates with the user terminal using a second carrier of a higher frequency band than the first carrier, the radio base station comprising:
- an acquisition section configured to acquire position-related information of the user terminal by communication with the user terminal using the first carrier;
- and
- a reporting section configured to report the position-related information of the user terminal acquired by the acquisition section, or generated beam forming information for forming a transmission beam directed from the small base station to the user terminal based on the position-related information of the user terminal.
A radio communication system to allow a user terminal that communicates with a macro base station forming a macro cell, using a first carrier, to communicate with a small base station forming a small cell that is smaller than the macro cell, using a second carrier of a higher frequency band than the first carrier, wherein:
- beam forming information for forming a transmission beam directed from the small base station to the user terminal is generated based on position-related information of the user terminal acquired by communication between the macro base station and the user terminal using the first carrier;
- and
- the small base station precodes at least one of a common control signal and a reference signal that are common in the small cell, based on the beam forming information, and transmits the precoded signal from a plurality of transmitting antennas using the second carrier.
Dependencies are inferred from the claim text.