BASE STATION, RELAY DEVICE AND COMMUNICATION SYSTEM

• US 20120307719A1
• Filed: 02/18/2011
• Published: 12/06/2012
• Est. Priority Date: 02/19/2010
• Status: Active Grant

• Current Assignee: Kyocera Corporation
• Original Assignee: Kyocera Corporation
• Inventors: Nakasato, Yuuki
• Granted Patent: US 8,885,544 B2
• Time in Patent Office: Days
• US Class Current: 370/315
• CPC Class Codes: H04B 7/155 Ground-based stations H04B7/204 takes precedence
• CPC Class Codes: H04W 72/04 Wireless resource allocation
• CPC Class Codes: H04W 84/047 using dedicated repeater stations

Abstract

A base station includes a reception unit, a channel allocation unit, a relay channel designation unit, and a transmission unit. The reception unit receives a signal from a communication terminal communicating with the base station via a relay device. The channel allocation unit allocates a communication channel to the communication terminal communicating with the base station via the relay device. The relay channel designation unit designates a communication channel for a signal relayed by the relay device such that the communication channel allocated by the channel allocation unit to the communication terminal communicating with the base station via the relay device is included therein. The transmission unit transmits, to the relay device, a notification signal for notifying the relay device of the communication channel designated by the relay channel designation unit.

Claims

1. A base station communicating with a communication terminal via a relay device, the base station comprising:

a reception unit for receiving a signal from a communication terminal communicating with the base station via the relay device;

a channel allocation unit for allocating a communication channel to a communication terminal communicating with the base station via the relay device;

a relay channel designation unit for designating a communication channel for a signal relayed by the relay device such that a communication channel allocated by the channel allocation unit to a communication terminal communicating with the base station via the relay device is included therein; and

a transmission unit for transmitting, to the relay device, a notification signal for notifying the relay device of a communication channel designated by the relay channel designation unit.

2. The base station according to claim 1, wherein

the reception unit also receives a signal from a communication terminal communicating directly with the base station,

the channel allocation unit also allocates a communication channel to a communication terminal communicating directly with the base station,

a reception timing when the reception unit receives a signal from a communication terminal communicating with the base station via the relay device is delayed from a reception timing when the reception unit receives a signal from a communication terminal communicating directly with the base station,

the base station further comprises an identification unit for identifying a communication terminal communicating with the base station via the relay device based on a reception timing when the reception unit receives a signal from a communication terminal.

3. The base station according to claim 1, wherein

the channel allocation unit allocates, as a communication channel, at least one of a plurality of unit radio resources identified on a time-frequency plane to a communication terminal,

the relay channel designation unit designates only a communication channel allocated to a communication terminal communicating with the base station via the relay device, as a communication channel for a signal relayed by the relay device.

4. The base station according to claim 1, wherein

the channel allocation unit allocates, as a communication channel, at least one of a plurality of unit radio resources identified on a time-frequency plane to a communication terminal,

the relay channel designation unit designates a communication channel for a signal relayed by the relay device with using, as a unit of designation, a resource group consisting of a plurality of unit radio resources arranged in a time direction or with using, as a unit of designation, a resource group consisting of a plurality of unit radio resources arranged in a frequency direction.

5. The base station according to claim 4, wherein

in a case of allocating an additional communication channel to a communication terminal communicating with the base station via the relay device,

the channel allocation unit determines the additional communication channel from at least one said resource group designated as a communication channel for a signal relayed by the relay device.

6. The base station according to claim 4, wherein

the reception unit also receives a signal from a communication terminal communicating directly with the base station,

the channel allocation unit also allocates a communication channel to a communication terminal communicating directly with the base station,

the channel allocation unit allocates, to a communication terminal communicating directly with the base station, a communication channel that does not belong to at least one said resource group designated as a communication channel for a signal relayed by the relay device.

7. The base station according to claim 1, wherein

the reception unit also receives a signal from a communication terminal communicating directly with the base station,

the channel allocation unit also allocates a communication channel to a communication terminal communicating directly with the base station,

in a case where, when the relay channel designation unit designates a communication channel for a signal relayed by the relay device, a communication channel has been already allocated to a communication terminal communicating directly with the base station, the relay channel designation unit designates, while avoiding the commucation channel which has been already allocated, a communication channel for a signal relayed by the relay device.

8. The base station according to claim 1, wherein

the reception unit also receives a signal from a communication terminal communicating directly with the base station,

the channel allocation unit also allocates a communication channel to a communication terminal communicating directly with the base station,

the reception unit receives a signal from a communication terminal communicating with the base station via the relay device, at a timing different from a timing when a signal from a communication terminal communicating directly with the base station is received,

the base station further comprises a common channel setting unit for setting common channels for uplink communication to both of a first reception timing and a second reception timing, the first reception timing being a timing when the reception unit receives a signal from a communication terminal communicating directly with the base station, the second reception timing being a timing when the reception unit receives a signal from a communication terminal communicating with the base station via the relay device,

in a surrounding base station located in surroundings of the base station, a common channel for downlink communication is not set to a transmission timing that is paired with the second reception timing in a communication frame to which the second reception timing belongs,

the transmission unit transmits the notification signal at the transmission timing.

9. A base station for which the base station according to claim 8 is provided as a surrounding base station thereof, the base station comprising:

a reception unit for receiving a signal from the surrounding base station; and

a common channel setting unit for setting a common channel for downlink communication to a timing other than a timing when the reception unit receives a signal of a common channel in the surrounding base station,

wherein

in a case where the reception unit receives a signal transmitted by the surrounding base station at a transmission timing paired with the first reception timing in a communication frame to which the first reception timing belongs, the common channel setting unit excludes, from a candidate to which a common channel for downlink communication is set, a transmission timing that is later than a timing of receiving the signal by an amount of delay of the second reception timing relative to the first reception timing,

in a case where the reception unit receives the notification signal transmitted by the surrounding base station, the common channel setting unit does not exclude, from a candidate to which a common channel for downlink communication is set, a transmission timing that is later than a timing of receiving the notification signal by the amount of delay.

10. A relay device for relaying a signal from a communication terminal to a base station and relaying a signal from a base station to a communication terminal, the relay device comprising:

a base station side communication unit for communicating with a base station;

a terminal side communication unit for communicating with a communication terminal; and

a control unit for controlling the base station side communication unit and the terminal side communication unit,

wherein

the base station side communication unit receives a notification signal transmitted from the base station, the notification signal being for notifying a communication channel for a signal relayed by the relay device,

the control unit controls the base station side communication unit and the terminal side communication unit such that the relay device relays a signal of a communication channel notified by the notification signal.

11. A communication system comprising:

a base station communicating with a communication terminal via a relay device; and

a relay device relaying a signal from a communication terminal to the base station and relaying a signal from the base station to a communication terminal,

wherein

the base station includes;

a reception unit for receiving a signal from a communication terminal communicating with the base station via the relay device;

a channel allocation unit for allocating a communication channel to a communication terminal communicating with the base station via the relay device;

a relay channel designation unit for designating a communication channel for a signal relayed by the relay device such that a communication channel allocated by the channel allocation unit to a communication terminal communicating with the base station via a relay device is included therein; and

a transmission unit for transmitting, to the relay device, a notification signal for notifying the relay device of a communication channel designated by the relay channel designation unit,

the relay device includes;

a base station side communication unit for communicating with the base station;

a terminal side communication unit for communicating with a communication terminal; and

a control unit for controlling the base station side communication unit and the terminal side communication unit,

the base station side communication unit receives a notification signal transmitted from the base station, the notification signal being for notifying a communication channel for a signal relayed by the relay device,

the control unit controls the base station side communication unit and the terminal side communication unit such that the relay device relays a signal of a communication channel notified by the notification signal.