MOBILE COMMUNICATION SYSTEM, BASE STATION AND COMMUNICATION CONTROL METHOD

• US 20140362801A1
• Filed: 01/01/2013
• Published: 12/11/2014
• Est. Priority Date: 01/19/2012
• Status: Active Grant

• Current Assignee: Kyocera Corporation
• Original Assignee: Kyocera Corporation
• Inventors: Morita, Kugo
• Granted Patent: US 9,668,246 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04B 7/024 Co-operative use of antennas of several sites, e.g. in co-ordinated multipoint or co-operative multiple-input multiple-output [MIMO] systems
• CPC Class Codes: H04L 5/0035 Resource allocation in a cooperative multipoint environment
• CPC Class Codes: H04W 72/21 in the uplink direction of a wireless link, i.e. towards the network
• CPC Class Codes: H04W 72/27 between access points
• CPC Class Codes: H04W 76/15 Setup of multiple wireless link connections

Abstract

In a mobile communication system in which a plurality of base stations included in a CoMP cooperating set allocate a same communication resource to a user terminal to perform a communication, each of the plurality of base stations comprises a notification unit that notifies another base station included in the CoMP cooperating set of a communication resource of allocation candidate for the user terminal in the base station itself; a receiver that receives a notification of a communication resource of allocation candidate for the user terminal in another base station included in the CoMP cooperating set from the other base station; and a selector that selects a communication resource to be allocated to the user terminal from communication resources of allocation candidates in the plurality of base stations, based on the notification received by the receiver.

Claims

1. A mobile communication system in which a plurality of base stations included in a CoMP cooperating set allocate a same communication resource to a user terminal to perform communication, wherein

each of the plurality of base stations comprises a notification unit that notifies another base station included in the CoMP cooperating set of a communication resource of allocation candidate for the user terminal in the base station itself;

a receiver that receives a notification of a communication resource of allocation candidate for the user terminal in the other base station included in the CoMP cooperating set from the other base station; and

a selector that selects a communication resource to be allocated to the user terminal from communication resources of allocation candidates in the plurality of base stations, based on the notification received by the receiver.

2. The mobile communication system according to claim 1, wherein the selector selects a communication resource to be allocated to the user terminal from the communication resources of allocation candidates in the plurality of base stations, according to a selection rule common to the plurality of base stations.

3. The mobile communication system according to claim 2, wherein

the notification unit creates a timing advance value to adjust uplink transmission timing and further notifies the other base station included in the CoMP cooperating set of the created timing advance value,

the receiver further receives a timing advance value created by the other base station included in the CoMP cooperating set from the other base station, and

the common selection rule is a rule that a communication resource of allocation candidate in a base station that creates a timing advance value causing the longest delay in uplink transmission timing among the plurality of base stations is to be selected as a communication resource to be allocated to the user terminal.

4. The mobile communication system according to claim 2, wherein

the notification unit selects MCS to be applied by the base station to the user terminal and further notifies the other base station included in the CoMP cooperating set of the selected MCS,

the receiver further receives MCS between the user terminal and the other base station included in the CoMP cooperating set from the other base station, and

the common selection rule is a rule that a communication resource of allocation candidate in a base station that selects MCS having the highest transmission rate among the plurality of base stations is to be selected as a communication resource to be allocated to the user terminal.

5-6. -6. (canceled)

7. A mobile communication system in which a plurality of base stations included in a CoMP cooperating set performs uplink CoMP communication with a user terminal, wherein

each of the plurality of base stations comprises

a transmission unit that creates a timing advance value for adjusting data transmission timing of the user terminal and transmits the created timing advance value to another base station included in the CoMP cooperating set,

a receiver that receives a timing advance value created in the other base station from the other base station included in the CoMP cooperating set, and

a notification unit that notifies the user terminal of the timing advance value selected among the timing advance values in the plurality of base stations based on the timing advance value received by the receiver.

8. The mobile communication system according to claim 7, wherein the notification unit selects a timing advance value causing the longest delay in the data transmission timing among the timing advance values in the plurality of base stations, and notifies the user terminal of the selected timing advance value.

9. The mobile communication system according to claim 7, wherein

each of the plurality of base stations further comprises

a storage for storing the timing advance value received by the receiver;

and

an update unit that updates the timing advance value stored in the storage with the received timing advance value every time the receiver receives the timing advance value, and

the notification unit selects the timing advance value that the user terminal is to be notified of among the timing advance values stored in the storage and notifies the user terminal of the selected timing advance value.

10. The mobile communication system according to claim 7, wherein if PDSCH resource to be allocated to the user terminal has free space, the notification unit notifies the user terminal of the selected timing advance value using the free space of the PDSCH resource.

11. The mobile communication system according to claim 7, wherein

the user terminal has a first timer for determining a valid period of a received timing advance value,

a main base station among the plurality of base stations has a second timer corresponding to the first timer, and

the main base station controls so as to notify the user terminal of the selected timing advance value when the second timer will expire soon.

12-13. -13. (canceled)