MOBILE COMMUNICATION SYSTEM

• US 20150257184A1
• Filed: 09/11/2013
• Published: 09/10/2015
• Est. Priority Date: 09/26/2012
• Status: Active Grant

• Current Assignee: Kyocera Corporation
• Original Assignee: Kyocera Corporation
• Inventors: Yamazaki, Chiharu, Fukuta, Noriyoshi
• Granted Patent: US 9,591,671 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04L 5/0044 allocation of payload
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 5/0057 Physical resource allocation for CQI
• CPC Class Codes: H04L 5/0073 Allocation arrangements that take into account other cell interferences for intercell interference mitigation or co-ordination in orthogonal multiplex systems H04J11/005
• CPC Class Codes: H04W 72/02 Selection of wireless resources by user or terminal
• CPC Class Codes: H04W 72/04 Wireless resource allocation
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access
• CPC Class Codes: H04W 76/11 Allocation or use of connection identifiers
• CPC Class Codes: H04W 76/14 Direct-mode setup
• CPC Class Codes: H04W 8/005 Discovery of network devices, e.g. terminals

Abstract

A mobile communication system supports cellular communication in which data communication is performed between a network and a user terminal and D2D communication in which data communication is directly performed among two or more user terminals. The D2D communication is performed by using a part of the uplink radio resources of the cellular communication. The uplink radio resources include a specific radio resource that is used in the transmission of a predetermined uplink signal in the cellular communication. The use of the specific radio resource in the D2D communication is regulated.

Claims

1. A mobile communication system which supports:

cellular communication in which data communication is performed between a network and a user terminal; and

D2D communication in which data communication is directly performed among two or more user terminals, wherein

the D2D communication is performed by using a part of uplink radio resources of the cellular communication,

the uplink radio resources include a specific radio resource that is used in a transmission of a predetermined uplink signal in the cellular communication, and

a use of the specific radio resource in the D2D communication is regulated.

2. The mobile communication system according to claim 1, wherein

the predetermined uplink signal is an uplink reference signal used at least in an uplink channel estimation, and

the specific radio resource is an uplink reference signal resource.

3. The mobile communication system according to claim 2, wherein the uplink reference signal is at least one of a sounding reference signal (SRS) and a demodulation reference signal (DMRS).

4. The mobile communication system according to claim 2, wherein use of the uplink reference signal resource in a symbol unit is regulated in the D2D communication.

5. The mobile communication system according to claim 1, wherein

the predetermined uplink signal is an uplink control signal used in a control of the cellular communication, and

the specific radio resource is an uplink control signal resource.

6. The mobile communication system according to claim 5, wherein the uplink control signal is at least one of a signal that is transmitted on a physical uplink control channel (PUCCH) and a signal that is transmitted on a physical random access channel (PRACH).

7. The mobile communication system according to claim 5, wherein a use of the uplink control signal resource is regulated in a resource block unit, in the D2D communication.

8. The mobile communication system according to claim 1, wherein the D2D communication is performed by using a radio resource other than the specific radio resource from among the uplink radio resources, without using the specific radio resource.

9. The mobile communication system according to claim 8, wherein, when D2D resource assignment, which is a radio resource assignment for the D2D communication, is performed at an initiative of a base station, the base station that performs the D2D resource assignment does not assign the specific radio resource to the D2D communication.

10. The mobile communication system according to claim 8, wherein, when D2D resource assignment, which is a radio resource assignment for the D2D communication, is performed at the initiative of a user terminal, the user terminal that performs the D2D resource assignment does not assign the specific radio resource to the D2D communication.

11. The mobile communication system according to claim 8, wherein, even when the specific radio resource is assigned to a user terminal by D2D resource assignment, which is a radio resource assignment for the D2D communication, the user terminal to which the specific radio resource is assigned does not use the specific radio resource in the D2D communication.

12. The mobile communication system according to claim 1, wherein, when a D2D communication signal is transmitted by using the specific radio resource in the D2D communication, a transmission power of the D2D communication signal corresponding to the specific radio resource is set to a lower value than a predetermined value.

13. The mobile communication system according to claim 12, wherein, when a D2D communication signal is transmitted by using the specific radio resource in the D2D communication, and when a D2D power control, which is a transmission power control for the D2D communication, is performed at an initiative of a base station, the base station that performs the D2D power control sets a transmission power of the D2D communication signal corresponding to the specific radio resource to a lower value than the predetermined value.

14. The mobile communication system according to claim 12, wherein, when a D2D communication signal is transmitted by using the specific radio resource in the D2D communication, and when a D2D power control, which is a transmission power control for the D2D communication, is performed at an initiative of a user terminal, the user terminal that performs the D2D power control sets a transmission power of the D2D communication signal corresponding to the specific radio resource to a lower value than the predetermined value.

15. The mobile communication system according to claim 1, wherein a use of the specific radio resource in the D2D communication is regulated only to a user terminal that satisfies a predetermined condition, and

the predetermined condition is a condition where a path loss with a base station included in the network is smaller than a threshold.

16. A mobile communication system which supports:

cellular communication in which data communication is performed between a network and a user terminal; and

D2D communication in which data communication is directly performed among two or more user terminals, wherein

the D2D communication is performed by using a part of downlink radio resources of the cellular communication,

the downlink radio resources include a specific radio resource that is used in a transmission of a predetermined downlink signal in the cellular communication, and

a use of the specific radio resource in the D2D communication is regulated.

17. The mobile communication system according to claim 16, wherein the predetermined downlink signal is a downlink control signal that is used in a control of the cellular communication.

18. The mobile communication system according to claim 17, wherein the downlink control signal is at least one of a synchronization signal and a signal that is transmitted on a physical broadcast channel (PBCH).

19. The mobile communication system according to claim 16, wherein

the predetermined downlink signal is an MBMS (Multimedia Broadcast Multicast Service) signal, and

the specific radio resource is an MBSFN (MBMS Single Frequency Network) subframe.

20. The mobile communication system according to claim 16, wherein the D2D communication is performed by using a radio resource other than the specific radio resource from among the downlink radio resources, without using the specific radio resource.

21. The mobile communication system according to claim 20, wherein, when D2D resource assignment, which is a radio resource assignment for the D2D communication, is performed at an initiative of a base station, the base station that performs the D2D resource assignment does not assign the specific radio resource to the D2D communication.

22. The mobile communication system according to claim 20, wherein, when D2D resource assignment, which is a radio resource assignment for the D2D communication, is performed at the initiative of a user terminal, the user terminal that performs the D2D resource assignment does not assign the specific radio resource to the D2D communication.

23. The mobile communication system according to claim 20, wherein, even when the specific radio resource is assigned to a user terminal by the D2D resource assignment, which is a radio resource assignment for the D2D communication, the user terminal to which the specific radio resource is assigned does not use the specific radio resource in the D2D communication.

24. The mobile communication system according to claim 16, wherein, when a D2D communication signal is transmitted by using the specific radio resource in the D2D communication, a transmission power of the D2D communication signal corresponding to the specific radio resource is set to a lower value than a predetermined value.

25. The mobile communication system according to claim 24, wherein, when a D2D communication signal is transmitted by using the specific radio resource in the D2D communication, and when a D2D power control, which is a transmission power control for the D2D communication, is performed at an initiative of a base station, the base station that performs the D2D power control sets a transmission power of the D2D communication signal corresponding to the specific radio resource to a lower value than the predetermined value.

26. The mobile communication system according to claim 24, wherein, when a D2D communication signal is transmitted by using the specific radio resource in the D2D communication, and when a D2D power control, which is a transmission power control for the D2D communication, is performed at an initiative of a user terminal, the user terminal that performs the D2D power control sets a transmission power of the D2D communication signal corresponding to the specific radio resource to a lower value than the predetermined value.

27. The mobile communication system according to claim 16, wherein a use of the specific radio resource in the D2D communication is regulated only to a user terminal that satisfies a predetermined condition, and

the predetermined condition is a condition where a path loss with a base station included in the network is larger than a threshold.

28. A mobile communication system which supports:

cellular communication in which data communication is performed between a network and a user terminal; and

D2D communication in which data communication is directly performed among two or more user terminals, wherein

downlink radio resources of the cellular communication includes a specific subframe for realizing a specific function in the cellular communication, and

the D2D communication is performed by using at least a part of the specific subframe.

29. The mobile communication system according to claim 28, wherein

the specific function is an MBMS (Multimedia Broadcast Multicast Service) function, and

the specific subframe is an MBSFN (MBMS Single Frequency Network) subframe.

30. The mobile communication system according to claim 29, wherein a base station that performs radio resource assignment for the D2D communication controls whether to assign at least a part of the MBSFN subframes to the D2D communication on the basis of an MBMS interest information notified from a user terminal served by the base station.

31. The mobile communication system according to claim 30, wherein

the MBMS interest information includes frequency information indicating a frequency of distribution of MBMS data that the user terminal desires to receive, and

the base station controls whether to assign at least a part of the MBSFN subframes to the D2D communication on the basis of the frequency information included in the MBMS interest information.

32. The mobile communication system according to claim 29, wherein a base station that performs radio resource assignment for the D2D communication controls whether to assign at least a part of the MBSFN subframes to the D2D communication on the basis of MBMS counting information notified from a user terminal served by the base station.

33. The mobile communication system according to claim 28, wherein

the specific function is an ICIC (Inter-Cell Interference Coordination) function, and

the specific subframe is an ABS (Almost Blank Subframe).

34. The mobile communication system according to claim 33, wherein a base station that performs radio resource assignment for the D2D communication assigns at least a part of the ABS to the D2D communication if the ABS is set.

35. The mobile communication system according to claim 28, wherein a use of the specific subframe in the D2D communication is allowed only to a user terminal that satisfies a predetermined condition, and

the predetermined condition is a condition where a path loss with a base station included in the network is smaller than a threshold.