Communication system, communication apparatus, communication method and computer program

• US 8,861,425 B2
• Filed: 08/10/2010
• Issued: 10/14/2014
• Est. Priority Date: 08/17/2009
• Status: Active Grant

• Current Assignee: Pantech Corporation (Ideahub, Inc.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Takano, Hiroaki
• Primary Examiner(s): Rinehart, Mark
• Assistant Examiner(s): ANWAR, MOHAMMAD S
• Application Number:
  US13/389,617
• Publication Number:
  US 20120140702A1
• Time in Patent Office: 1,526 Days
• Field of Search: 370/315, 370/328, 370/338
• US Class Current: 370/315
• CPC Class Codes: H04B 7/15542 Selecting at relay station its transmit and receive resources selection of wireless resources by user or terminal H04W72/02; arrangements affording multiple use of the transmission path by two-dimensional division of the resources H04L5/0003, or by allocating sub-channels H04L5/003
• CPC Class Codes: H04B 7/2606 Arrangements for base station coverage control, e.g. by using relays in tunnels
• CPC Class Codes: H04J 11/005 of intercell interference
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0037 Inter-user or inter-terminal allocation
• CPC Class Codes: H04L 5/0062 Avoidance of ingress interference, e.g. ham radio channels
• 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: H04L 5/0094 Indication of how sub-channels of the path are allocated
• CPC Class Codes: H04W 72/54 based on quality criteria
• CPC Class Codes: H04W 72/56 based on priority criteria
• CPC Class Codes: H04W 84/047 using dedicated repeater stations

Abstract

By deciding positions of frequencies used via a relay station by a system in advance for assignment of boundary frequencies, frequencies of a central frequency more likely to be affected by the relay station are also mapped by avoiding a signal thereof. Alternatively, an adjacent cell whose central frequency is affected changes depending on a position of the relay station and thus, locations set to be highly likely to interfere with the central frequency of the adjacent cell is reduced by setting a region of the boundary frequencies permitted to the relay station in accordance with the position of the relay station.

Claims

1. A communication system, comprising:

a first cell and a second cell adjacent to each other, each of which permitted to install a relay station to relay between a base station and a mobile station, wherein

the base station includes

a position information holding memory that stores position information of the relay station and position information of the first cell and second cell, and

a relay station frequency assignment decision circuit that estimates position information of one of the first cell and the second cell based on the position information stored in the position information holding memory and decides restricted bands used by the relay station from among boundary frequencies of the first cell, and

a frequency to the mobile station in the second cell is assigned by avoiding the restricted bands or lowering a degree of priority on the second cell side.

2. A communication system, comprising:

a first cell and a second cell adjacent to each other, each of which composed of a center region inside the cell using a central frequency and a boundary region at cell ends using boundary frequencies by a multi-cell frequency repetition and permitted to install a relay station to relay between a base station and a mobile station, wherein

the base station includes

a position information holding memory that stores position information of the relay station and position information of the first cell and second cell, and

a relay station frequency assignment decision circuit that estimates position information of one of the first cell and the second cell based on the position information stored in the position information holding memory and decides restricted bands used by the relay station from among boundary frequencies of the first cell, and

the central frequency of the second cell is assigned to the mobile station by avoiding the restricted bands or lowering a degree of priority on the second cell side.

3. The communication system according to claim 2, wherein

frequency hopping is allowed for frequency assignment to the relay station over time on the first cell side.

4. A communication apparatus operating as a base station in a communication system constituted by the base station managing radio resources in a local cell composed of an internal center region and a boundary region at edges, a mobile station, and a relay station relaying between the base station and the mobile station belonging to the relay station, comprising:

a position information holding memory that stores position information of the relay station and position information of the local cell and an adjacent cell;

a relay station frequency assignment decision circuit that estimates the adjacent cell close to the relay station based on the position information stored in the position information holding memory and decides a restricted band of boundary frequencies to be assigned to the relay station;

a notification circuit that notifies the base station of the adjacent cell of the restricted band decided by the relay station frequency assignment decision circuit; and

a scheduler that schedules radio resources in the local cell conforming to the restricted band decided by the relay station frequency assignment decision circuit.

5. The communication apparatus according to claim 4, wherein

the relay station frequency assignment decision circuit allows frequency hopping for frequency assignment to the relay station over time.

6. The communication apparatus according to claim 4, wherein

when the restricted band is notified from the adjacent cell, the scheduler assigns a central frequency of the local cell by avoiding the restricted band of the adjacent cell or lowering an order of priority thereof.

7. A communication method for operating as a base station in a communication system constituted by the base station managing radio resources in a local cell composed of an internal center region and a boundary region at edges, a mobile station, and a relay station relaying between the base station and the mobile station belonging to the relay station, comprising the steps of:

acquiring position information of the relay station and position information of the local cell;

estimating the adjacent cell close to the relay station based on the acquired position information;

deciding a restricted band of boundary frequencies to be assigned to the relay station;

notifying the base station of the adjacent cell of the restricted band decided in the relay station frequency assignment decision step;

scheduling radio resources in the local cell conforming to the restricted band decided in the relay station frequency assignment decision step; and

when the restricted band is notified from the adjacent cell, assigning a central frequency of the local cell by avoiding the restricted band of the adjacent cell or lowering an order of priority thereof.

8. A non-transitory computer readable medium that stores a program causing a computer to execute a processing operation as a base station in a communication system constituted by the base station managing radio resources in a local cell composed of an internal center region and a boundary region at edges, a mobile station, and a relay station relaying between the base station and the mobile station belonging to the relay station, the computer caused to:

store position information of the relay station and position information of the local cell and an adjacent cell;

estimate the adjacent cell close to the relay station based on the position information stored in the position information holding memory and decide a restricted band of boundary frequencies to be assigned to the relay station;

notify the base station of the adjacent cell of the decided restricted band decided; and

schedule radio resources in the local cell conforming to the decided restricted band and, when the restricted band is notified from the adjacent cell, assigns a central frequency of the local cell by avoiding the restricted band of the adjacent cell or lowering an order of priority thereof.

9. A communication apparatus operating as a relay station in a communication system constituted by a base station managing radio resources in a local cell composed of an internal center region and a boundary region at edges, a mobile station, and the relay station relaying between the base station and the mobile station belonging to the relay station, comprising:

a communication circuit to perform transmission/reception with the base station and the mobile station;

a buffer that temporarily holds data to be relayed between the base station and the mobile station;

a scheduling information holding memory that stores scheduling information notified from the base station; and

a control circuit that controls communication operations by the communication circuit including a relay operation between the base station and the mobile station based on the scheduling information, wherein

the base station includes

a position information holding memory that stores position information of the relay station and position information of the local cell and an adjacent cell, and

a relay station frequency assignment decision circuit that estimates the adjacent cell close to the relay station based on the position information stored in the position information holding memory and decides a restricted band used by the relay station, and

the communication circuit transmits a radio signal by using the restricted band of boundary frequencies assigned to the relay station such that use as a central frequency in the adjacent cell is restricted.

10. A communication apparatus operating as a mobile station in a communication system constituted by a base station managing radio resources in a local cell composed of an internal center region and a boundary region at edges, the mobile station, and a relay station relaying between the base station and the mobile station belonging to the relay station, comprising:

a communication circuit to perform transmission/reception with the base station and the relay station;

a scheduling information holding memory that stores scheduling information notified from the base station; and

a control circuit that controls communication operations by the communication circuit based on the scheduling information, wherein

the base station includes

a position information holding memory that stores position information of the relay station and position information of the local cell and an adjacent cell, and

a relay station frequency assignment decision circuit that estimates the adjacent cell close to the relay station based on the position information stored in the position information holding memory and decides a restricted band used by the relay station, and

the communication circuit receives a radio signal using the restricted band of boundary frequencies assigned to the relay station such that use as a central frequency in the adjacent cell is restricted.

11. A communication system, comprising:

a first cell and a second cell adjacent to each other, each of which composed of a center region inside the cell using a central frequency and a boundary region at cell ends using boundary frequencies by a multi-cell frequency repetition and permitted to install a relay station to relay between a base station and a mobile station, wherein

the base station includes

a position information holding memory that stores position information of the relay station and position information of the first cell and second cell, and

a relay station frequency assignment decision circuit that estimates position information of one of the first cell and the second cell based on the position information stored in the position information holding memory and decides non-interference bands of the central frequency of the second cell that should not be interfered, and

an assignment of the non-interference bands of the boundary frequencies of the first cell to the relay station is prohibited on the first cell side.

12. A communication apparatus operating as a base station in a communication system constituted by the base station managing radio resources in a local cell composed of an internal center region and a boundary region at edges, a mobile station, and a relay station relaying between the base station and the mobile station belonging to the relay station, comprising:

a position information holding memory that stores position information of the relay station and position information of the local cell and an adjacent cell;

a relay station frequency assignment decision circuit that estimates the adjacent cell close to the relay station based on the position information stored in the position information holding memory and decides a non-interference band of a central frequency that should not be interfered with;

a notification circuit that notifies the base station of the adjacent cell of the non-interference band decided by the relay station frequency assignment decision circuit; and

a scheduler that schedules radio resources in the local cell, when the non-interference band is notified from the adjacent cell, by avoiding the non-interference band of boundary frequencies of the adjacent cell.

13. A communication method for operating as a base station in a communication system constituted by the base station managing radio resources in a local cell composed of an internal center region and a boundary region at edges, a mobile station, and a relay station relaying between the base station and the mobile station belonging to the relay station, comprising the steps of:

acquiring position information of the relay station and position information of the local cell;

estimating the adjacent cell close to the relay station based on the acquired position information stored;

deciding a non-interference band of a central frequency that should not be interfered with;

notifying the base station of the adjacent cell of the non-interference band decided in the relay station frequency assignment decision step; and

scheduling radio resources in the local cell, when the non-interference band is notified from the adjacent cell, by avoiding the non-interference band of boundary frequencies of the adjacent cell.

14. A non-transitory computer readable medium that stores a program causing a computer to execute a processing operation as a base station in a communication system constituted by the base station managing radio resources in a local cell composed of an internal center region and a boundary region at edges, a mobile station, and a relay station relaying between the base station and the mobile station belonging to the relay station, the computer caused to:

store position information of the relay station and position information of the local cell and an adjacent cell;

estimate the adjacent cell close to the relay station based on the position information stored in the position information holding memory and decide a non-interference band of a central frequency that should not be interfered with;

notify the base station of the adjacent cell of the decided non-interference band; and

schedule radio resources in the local cell, when the non-interference band is notified from the adjacent cell, by avoiding the non-interference band of boundary frequencies of the adjacent cell.

15. A communication apparatus operating as a relay station in a communication system constituted by a base station managing radio resources in a local cell composed of an internal center region and a boundary region at edges, a mobile station, and the relay station relaying between the base station and the mobile station belonging to the relay station, comprising:

a communication circuit to perform transmission/reception with the base station and the mobile station;

a buffer that temporarily holds data to be relayed between the base station and the mobile station;

a scheduling information holding memory that stores scheduling information notified from the base station; and

a control circuit that controls communication operations by the communication circuit including a relay operation between the base station and the mobile station based on the scheduling information, wherein

the base station includes

a position information holding memory that stores position information of the relay station and position information of the local cell and an adjacent cell, and

a relay station frequency assignment decision circuit that estimates the adjacent cell close to the relay station based on the position information stored in the position information holding memory and decides non-interference bands of the central frequency of the second cell that should not be interfered, and

the communication circuit transmits a radio signal by using a frequency band assigned to the relay station from among boundary frequencies such that a non-interference band of a central frequency of the adjacent cell is avoided.

16. A communication apparatus operating as a mobile station in a communication system constituted by a base station managing radio resources in a local cell composed of an internal center region and a boundary region at edges, the mobile station, and a relay station relaying between the base station and the mobile station belonging to the relay station, comprising:

a communication circuit to perform transmission/reception with the base station and the relay station;

a scheduling information holding memory that stores scheduling information notified from the base station; and

a control circuit that controls communication operations by the communication circuit based on the scheduling information, wherein

the base station includes

a position information holding memory that stores position information of the relay station and position information of the local cell and an adjacent cell, and

a relay station frequency assignment decision circuit that estimates the adjacent cell close to the relay station based on the position information stored in the position information holding memory and decides non-interference bands of the central frequency of the second cell that should not be interfered, and

the communication circuit receives a radio signal using a frequency band assigned to the relay station from among boundary frequencies such that a non-interference band of a central frequency of the adjacent cell is avoided.

17. A communication system, comprising:

a plurality of local cells, each of which composed of a center region inside the cell using a central frequency and a boundary region at cell ends using boundary frequencies by a multi-cell frequency repetition and permitted to install a relay station to relay between a base station and a mobile station, wherein

the base station includes

a position information holding memory that stores position information of each relay station belonging to the local cell and position information of adjacent cells, and

a relay station frequency assignment decision circuit that estimates the adjacent cell close to the relay station based on the position information stored in the position information holding memory, and decides a frequency to be assigned to the relay station from among boundary frequencies of the local cell while avoiding bands that become interference components to the central frequency of the adjacent cell near an installation location of the relay station, and

at least in one local cell, the frequency from among the boundary frequencies of the local cell is assigned to the relay station.

18. The communication system according to claim 17, wherein

the communication system determines, in a group of plurality of cells which assigns common boundary frequencies, among those which are central frequencies of common adjacent cells and the common boundary frequencies, a common boundary frequency to be assigned to a relay station that is arranged close to the common adjacent cells.

19. A communication apparatus operating as a base station in a communication system constituted by the base station managing radio resources in a local cell composed of an internal center region and a boundary region at edges, a mobile station, and a relay station relaying between the base station and the mobile station belonging to the relay station, comprising:

a position information holding memory that stores position information of each relay station belonging to the local cell and position information of adjacent cells;

a relay station frequency assignment decision circuit that estimates the adjacent cell close to the relay station based on the position information stored in the position information holding memory and decides a given interference band used by the relay station from among boundary frequencies of the local cell while avoiding a region highly likely to interfere with a central frequency of the adjacent cell;

a notification circuit that notifies the adjacent cell of information about the given interference band decided by the relay station frequency assignment decision circuit; and

a scheduler that assigns the frequency from among the boundary frequencies of the local cell to the relay station in the boundary region of the local cell while avoiding bands that become interference components to the central frequency of an adjacent cell near an installation location of the relay station and also assigns the central frequency of the local cell while avoiding the given interference band notified from the adjacent cell.

20. A communication method for operating as a base station in a communication system constituted by the base station managing radio resources in a local cell composed of an internal center region and a boundary region at edges, a mobile station, and a relay station relaying between the base station and the mobile station belonging to the relay station, comprising the steps of:

acquiring position information of each relay station belonging to the local cell and position information of adjacent cells;

estimating the adjacent cell close to the relay station based on the position information and deciding a given interference band used by the relay station from among boundary frequencies of the local cell while avoiding a region highly likely to interfere with a central frequency of the adjacent cell;

notifying the adjacent cell of information about the given interference band decided in the relay station frequency assignment decision step; and

assigning the frequency from among the boundary frequencies of the local cell to the relay station in the boundary region of the local cell while avoiding bands that become interference components to the central frequency of an adjacent cell near an installation location of the relay station and also assigning the central frequency of the local cell while avoiding the given interference band notified from the adjacent cell.

21. A non-transitory computer readable medium that stores a program causing a computer to execute a processing operation as a base station in a communication system constituted by the base station managing radio resources in a local cell composed of an internal center region and a boundary region at edges, a mobile station, and a relay station relaying between the base station and the mobile station belonging to the relay station, the computer caused to:

store position information of each relay station belonging to the local cell and position information of adjacent cells;

estimate the adjacent cell close to the relay station based on the position information stored in the position information holding memory and decide a given interference band used by the relay station from among boundary frequencies of the local cell while avoiding a region highly likely to interfere with a central frequency of the adjacent cell;

notify the adjacent cell of information about the decided given interference band; and

assign the frequency from among the boundary frequencies of the local cell to the relay station in the boundary region of the local cell while avoiding bands that become interference components to the central frequency of an adjacent cell near an installation location of the relay station and also assign the central frequency of the local cell while avoiding the given interference band notified from the adjacent cell.

22. A communication apparatus operating as a relay station in a communication system constituted by a base station managing radio resources in a local cell composed of an internal center region and a boundary region at edges, a mobile station, and the relay station relaying between the base station and the mobile station belonging to the relay station, comprising:

a communication circuit to perform transmission/reception with the base station and the mobile station;

a buffer that temporarily holds data to be relayed between the base station and the mobile station;

a scheduling information holding memory that stores scheduling information notified from the base station; and

a control circuit that controls communication operations by the communication circuit including a relay operation between the base station and the mobile station based on the scheduling information, wherein

the base station includes

a position information holding memory that stores position information of the relay station and position information of adjacent cells, and

a relay station frequency assignment decision circuit that estimates the adjacent cell close to the relay station based on the position information stored in the position information holding memory and decides a given interference band used by the relay station from among boundary frequencies of the local cell while avoiding a region likely to interfere with a central frequency of the adjacent cell, and

the communication circuit transmits a radio signal by using a frequency band assigned to the relay station from among the boundary frequencies such that bands that become interference components to a central frequency of the adjacent cell near an installation location of the relay station is avoided.

23. A communication apparatus operating as a mobile station in a communication system constituted by a base station managing radio resources in a local cell composed of an internal center region and a boundary region at edges, the mobile station, and a relay station relaying between the base station and the mobile station belonging to the relay station, comprising:

a communication circuit to perform transmission/reception with the base station and the relay station;

a scheduling information holding memory that stores scheduling information notified from the base station; and

a control circuit that controls communication operations by the communication circuit based on the scheduling information, wherein

the base station includes

a position information holding memory that stores position information of the relay station and position information of adjacent cells, and

a relay station frequency assignment decision circuit that estimates the adjacent cell close to the relay station based on the position information stored in the position information holding memory and decides a given interference band used by the relay station from among boundary frequencies of the local cell while avoiding a region likely to interfere with a central frequency of the adjacent cell, and

the communication circuit receives a radio signal using a frequency band assigned to the relay station from among boundary frequencies such that bands that become interference components to a central frequency of the adjacent cell near an installation location of the relay station is avoided.

24. A communication apparatus operating as a base station in a communication system constituted by the base station managing radio resources in a local cell composed of an internal center region and a boundary region at edges, a mobile station, and a relay station relaying between the base station and the mobile station belonging to the relay station, comprising:

a position information holding memory that stores position information of each relay station belonging to the local cell and position information of adjacent cells;

a frequency information holding memory that stores boundary frequencies used by the local cell and boundary frequencies of each cell adjacent to the local cell;

a relay station frequency assignment decision circuit that estimates the adjacent cell close to the relay station based on the position information stored in the position information holding memory and fetches the boundary frequencies of the local cell and the adjacent cell stored in the frequency information holding memory to assign, to the relay station, the boundary frequencies to be common in a group of cells that assigns a common boundary frequency in a group of plurality of cells which assigns common boundary frequency, among those which are central frequency of common adjacent cells and the common boundary frequency, a common boundary frequency to be assigned to a relay station that is arranged close to the common adjacent cells; and

a scheduler that schedules a central frequency of the local cell while conforming to a region assigned to the relay station by the relay station frequency assignment decision circuit and avoiding a given interference band commonly assigned to the relay station arranged close to the local cell in a group of the adjacent cells that assign the common boundary frequency.

25. A communication method for operating as a base station in a communication system constituted by the base station managing radio resources in a local cell composed of an internal center region and a boundary region at edges, a mobile station, and a relay station relaying between the base station and the mobile station belonging to the relay station, comprising the steps of:

storing position information of each relay station belonging to the local cell and position information of adjacent cells;

storing boundary frequencies used by the local cell and boundary frequencies of each cell adjacent to the local cell;

estimating the adjacent cell close to the relay station based on the position information and also identifying the boundary frequencies of the adjacent cell to assign, to the relay station, the boundary frequencies to be common in a group of cells that assigns a common boundary frequency in a group of plurality of cells which assigns common boundary frequency, among those which are central frequency of common adjacent cells and the common boundary frequency, a common boundary frequency to be assigned to a relay station that is arranged close to the common adjacent cells; and

scheduling a central frequency of the local cell while conforming to a region assigned to the relay station in the relay station frequency assignment decision step and avoiding a given interference band commonly assigned to the relay station arranged close to the local cell in a group of the adjacent cells that assign the common boundary frequency.

26. A non-transitory computer readable medium that stores a program causing a computer to execute a processing operation as a base station in a communication system constituted by the base station managing radio resources in a local cell composed of an internal center region and a boundary region at edges, a mobile station, and a relay station relaying between the base station and the mobile station belonging to the relay station, the computer caused to:

store position information of each relay station belonging to the local cell and position information of adjacent cells;

store boundary frequencies used by the local cell and boundary frequencies of each cell adjacent to the local cell;

estimate the adjacent cell close to the relay station based on the position information stored in the position information holding memory and fetch the stored boundary frequencies of the local cell and the adjacent cell to assign, to the relay station, the boundary frequencies to be common in a group of cells that assigns a common boundary frequency in a group of plurality of cells which assigns common boundary frequency, among those which are central frequency of common adjacent cells and the common boundary frequency, a common boundary frequency to be assigned to a relay station that is arranged close to the common adjacent cells; and

schedule a central frequency of the local cell while conforming to a region assigned to the relay station and avoid a given interference band commonly assigned to the relay station arranged close to the local cell in a group of the adjacent cells that assign the common boundary frequency.

27. A communication apparatus operating as a relay station in a communication system constituted by a base station managing radio resources in a local cell composed of an internal center region and a boundary region at edges, a mobile station, and the relay station relaying between the base station and the mobile station belonging to the relay station, comprising:

a communication circuit to perform transmission/reception with the base station and the mobile station;

a buffer that temporarily holds data to be relayed between the base station and the mobile station;

a scheduling information holding memory that stores scheduling information notified from the base station; and

a control circuit that controls communication operations by the communication circuit including a relay operation between the base station and the mobile station based on the scheduling information, wherein

the base station includes

a position information holding memory that stores position information of the relay station and position information of adjacent cells, and

a relay station frequency assignment decision circuit that estimates the adjacent cell close to the relay station based on the position information stored in the position information holding memory and decides a given interference band used by the relay station from among boundary frequencies of the local cell while avoiding a region likely to interfere with a central frequency of the adjacent cell, and

the communication circuit transmits a radio signal by using a frequency to be common in a group of cells that assign a common boundary frequency to the boundary region among those which are central frequencies of the adjacent cells close to the local station and the boundary frequencies of the local cell.

28. A communication apparatus operating as a mobile station in a communication system constituted by a base station managing radio resources in a local cell composed of an internal center region and a boundary region at edges, the mobile station, and a relay station relaying between the base station and the mobile station belonging to the relay station, comprising:

a communication circuit to perform transmission/reception with the base station and the relay station;

a scheduling information holding memory that stores scheduling information notified from the base station; and

a control circuit that controls communication operations by the communication circuit based on the scheduling information, wherein

the base station includes

a position information holding memory that stores position information of the relay station and position information of adjacent cells, and

a relay station frequency assignment decision circuit that estimates the adjacent cell close to the relay station based on the position information stored in the position information holding memory and decides a given interference band used by the relay station from among boundary frequencies of the local cell while avoiding a region likely to interfere with a central frequency of the adjacent cell, and

the communication circuit receives a radio signal using a boundary frequency to be common in a group of cells that assign a common boundary frequency to the boundary region among those which are central frequencies of the adjacent cell near an installation location of the relay station and boundary frequencies of the local cell.

29. A communication apparatus operating as a first base station in a communication system constituted by the first base station managing radio resources in a local cell, a mobile station and a relay station relaying between the first base station and the mobile station belonging to the relay station, the communication apparatus comprising:

a notification circuit that notifies a second base station of an adjacent cell of interference information including at least a level of interference from the adjacent cell or a level of power managing for the radio resources; and

a scheduler that schedules the radio resources in the local cell in view of the interference information notified from the second base station in the adjacent cell.