Communication system, communication apparatus, communication method and computer program product

• US 8,824,355 B2
• Filed: 08/10/2010
• Issued: 09/02/2014
• Est. Priority Date: 08/10/2009
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Takano, Hiroaki
• Primary Examiner(s): Nguyen, Brian D
• Assistant Examiner(s): NGUYEN, TOAN D
• Application Number:
  US13/377,718
• Publication Number:
  US 20120082087A1
• Time in Patent Office: 1,484 Days
• Field of Search: 370/280, 370/315, 370/319, 370/321, 370/326, 455/442, 455/452.2
• US Class Current: 370/315
• CPC Class Codes: H04B 7/15507 Relay station based processing for cell extension or control of coverage area, network planning with network coordinated processing with regard to cell extension H04W16/26; network topologies using dedicated repeater stations H04W84/047; terminal devices adapted for relaying to or from an other terminal H04W88/04
• CPC Class Codes: H04B 7/15557 Selecting relay station operation mode, e.g. between amplify and forward mode, decode and forward mode or FDD - and TDD mode
• CPC Class Codes: H04W 72/51 based on terminal or device properties
• CPC Class Codes: H04W 84/047 using dedicated repeater stations

Abstract

A relay node (or relay station) operates as an intermediary entity in a transmission between a base station and a mobile station based on its position in a cell and the mobile station'"'"'s position in the cell. Since the cell is divided into multiple regions and different wireless resources are used in the multiple regions, the relay node employs the relevant wireless resources to be used in the communications based on positions of the relay node and the mobile station. When the relay station and the mobile station are both in the boundary region, it is possible to avoid interference in the relay station by adapting a relay mode that uses a boundary frequency avoiding interference with adjacent cells for both an uplink and a downlink and demultiplexes a relay link and an access link in a time direction for each of the uplink and the downlink. Similar adaptations are made when the mobile station and the relay station are in various positions within a center cell region and boundary cell region.

Claims

1. A mobile communication system comprising:

a base station including

a transmitter that provides wireless coverage in a cell, said cell being divided into a center region and a boundary region, said center region being surrounded by said boundary region, an outer edge of said boundary region defining an outer edge of said cell, said transmitter transmitting using first wireless resources allocated to the center region and second wireless resources allocated to the boundary region; and

a relay node, wherein

said relay node is configured to relay signals between said base station and a mobile station, said relay node including

controller circuitry configure to operate the relay node in a selected relay mode chosen from a plurality of relay modes based on position information of the mobile station and position information of the relay node relative to the boundary region and the center region, each of the plurality of relay modes specifying predetermined wireless resource assignments for communications between the base station and the relay node, and between the relay node and the mobile station,

a first relay mode of the plurality of relay modes specifying combined time division and frequency division multiple wireless resource access in which each of an uplink channel and a downlink channel employ mutually exclusive frequency bands, and

a second relay mode and a third relay mode of the plurality of relay modes employ mutually exclusive frequency bands.

2. The mobile communication system of claim 1, wherein:

said plurality of relay modes respectively define wireless resources and times to be used when providing an access link from the mobile station to the relay node, and a relay link from the relay node to the base station.

3. The mobile communication system of claim 2, wherein:

said controller circuitry is further configured to set the selected relay mode to be one of;

the first relay mode, when the position information of the relay node indicates that the relay node is in the center region and the position information of the mobile station indicates that said mobile station is in the boundary region;

the second relay mode, when the position information of the relay node and the position information the mobile station indicate that both the relay node and the mobile station are in the boundary region; and

the third relay mode, when the position information of the relay mode and the position information of the mobile station indicate that both the relay node and the mobile station are in the center region, wherein

said transmitter when using said first wireless resources to cover said center region transmits at a lower power than when using second wireless resources to cover said boundary region.

4. The mobile communication system of claim 1, wherein said first relay mode employs at least one of a set of frequency and time combinations, said combinations comprising:

employing one of the mutually exclusive frequency bands for the uplink during a first time segment, and another of the mutually exclusive frequency bands for the downlink during a second time segment, said first time segment not overlapping with said second time segment;

employing said one of the mutually exclusive frequency bands for the uplink during said first time segment, and another of the mutually exclusive frequency bands for the downlink during the second time segment, said first time segment not overlapping with said second time segment; and

employing a first sub-band of said one of the mutually exclusive frequency bands for a relay link portion of the uplink and employing a first sub-band of said another of the mutually exclusive frequency bands for an access link portion of the uplink, and employing a second sub-band of said one of the mutually exclusive frequency bands for a relay link portion of the downlink and employing a second sub-band of said another of the mutually exclusive frequency bands for an access link portion of the downlink.

5. The mobile communication system of claim 1, further comprising:

a position determination mechanism configured to determine the position information of said relay node, said position determination mechanism being included in one of said relay node and said base station.

6. A relay node in a mobile communication system that provides wireless coverage in a cell of a base station, said cell being divided into a center region and a boundary region, said center region being surrounded by said boundary region, said relay node comprising:

a transceiver configured to relay signals between said base station and a mobile station; and

controller circuitry configure to operate said relay node in a selected relay mode chosen from a plurality of relay modes based on position information of the mobile station and position information of the relay node relative to the boundary region and the center region, each of the plurality of relay modes specifying predetermined wireless resource assignments for communications between the base station and the relay node, and between the relay node and the mobile station,

a first relay mode of the plurality of relay modes specifying combined time division and frequency division multiple wireless resource access in which each of an uplink channel and a downlink channel employ mutually exclusive frequency bands, and

a second relay mode and a third relay mode of the plurality of relay modes employ mutually exclusive frequency bands.

7. The relay node of claim 6, wherein:

said plurality of relay modes respectively define wireless resources and times to be used when providing an access link from the mobile station to the relay node, and a relay link from the relay node to the base station.

8. The relay node of claim 6, wherein said first relay mode employs at least one of a set of frequency and time combinations, said combinations comprising:

employing one of the mutually exclusive frequency bands for the uplink during a first time segment, and another of the mutually exclusive frequency bands for the downlink during a second time segment, said first time segment not overlapping with said second time segment;

employing said one of the mutually exclusive frequency bands for the uplink during said first time segment, and another of the mutually exclusive frequency bands for the downlink during the second time segment, said first time segment not overlapping with said second time segment; and

employing a first sub-band of said one of the mutually exclusive frequency bands for a relay link portion of the uplink and employing a first sub-band of said another of the mutually exclusive frequency bands for an access link portion of the uplink, and employing a second sub-band of said one of the mutually exclusive frequency bands for a relay link portion of the downlink and employing a second sub-band of said another of the mutually exclusive frequency bands for an access link portion of the downlink.

9. A method for relaying wireless signals in a cell, said cell being divided into a center region and a boundary region, said center region being surrounded by said boundary region, an outer edge of said boundary region defining an outer edge of said cell, said method comprising:

transmitting, by processing circuitry, signals from a base station using wireless resources allocated to the center region and transmitting signals using wireless resources allocated to the boundary region,

relaying signals with a relay node between said base station and a mobile station, said relaying step including

selecting with a controller a relay mode from a plurality of relay modes based on position information of the mobile station and position information of the relay node, relative to the boundary region and the center region, each of the plurality of relay modes specifying predetermined wireless resource assignments for communications between the base station and the relay node, and between the relay node and the mobile station, wherein

a first relay mode of the plurality of relay modes specifying combined time division and frequency division multiple wireless resource access in which each of an uplink channel and a downlink channel employ mutually exclusive frequency bands, and

a second relay mode and a third relay mode of the plurality of relay modes employ mutually exclusive frequency bands.

10. The method of claim 9, wherein:

said plurality of relay modes respectively define wireless resources and times to be used when providing an access link from the mobile station to the relay node, and a relay link from the relay node to the base station.

11. The method of claim 10, wherein the controller operates the relay node in the selected relay mode, which is one of:

the first relay mode, when the position information of the relay node indicates that the relay node is in the center region and the position information of the mobile station indicates that said mobile station is in the boundary region;

the second relay mode, when the position information of the relay node and the position information the mobile station indicate that both the relay node and the mobile station are in the boundary region; and

the third relay mode, when the position information of the relay mode and the position information of the mobile station indicate that both the relay node and the mobile station are in the center region, wherein

said transmitter when using said first wireless resources to cover said center region transmits at a lower power than when using second wireless resources to cover said boundary region.

12. The method of claim 9, wherein said first relay mode employs at least one of a set of frequency and time combinations, said combinations comprising:

employing one of the mutually exclusive frequency bands for the uplink during a first time segment, and another of the mutually exclusive frequency bands for the downlink during a second time segment, said first time segment not overlapping with said second time segment;

employing said one of the mutually exclusive frequency bands for the uplink during said first time segment, and another of the mutually exclusive frequency bands for the downlink during the second time segment, said first time segment not overlapping with said second time segment; and

employing a first sub-band of said one of the mutually exclusive frequency bands for a relay link portion of the uplink and employing a first sub-band of said another of the mutually exclusive frequency bands for an access link portion of the uplink, and employing a second sub-band of said one of the mutually exclusive frequency bands for a relay link portion of the downlink and employing a second sub-band of said another of the mutually exclusive frequency bands for an access link portion of the downlink.

13. The method of claim 9, further comprising:

determining the position information of said relay node, said position determination mechanism being included in one of said relay node and said base station.

14. A mobile terminal for use in a mobile communication system that provides wireless coverage in a cell from a base station, said cell being divided into a center region and a boundary region, said center region being surrounded by said boundary region, said mobile terminal comprising:

a transceiver configured to exchange wireless signals with a base station via a relay node;

a non-transitory computer readable medium that holds scheduling information corresponding to a selected relay mode for said relay node; and

a controller configured to change which wireless resources are used in communications with said relay node based on the selected relay mode, said selected relay mode chosen from a plurality of relay modes based on position information of the mobile terminal and position information of the relay node, each of the plurality of relay modes specifying predetermined wireless resource assignments for communications between the base station and the relay node, and between the relay node and mobile terminal,

a first relay mode of the plurality of relay modes specifying combined time division and frequency division multiple wireless resource access in which each of an uplink channel and a downlink channel employ mutually exclusive frequency bands, and

a second relay mode and a third relay mode of the plurality of relay modes use mutually exclusive frequency bands.

15. The mobile terminal of claim 14, wherein said controller is configured to selectably operate in one of said first relay mode, said second relay mode, and said third relay mode,

said first relay mode being selected when the position information of the relay node indicates that the relay node is in the center region and the position information of the mobile station indicates that said mobile station is in the boundary region,

said second relay mode being selected when the position information of the relay node and the position information the mobile station indicate that both the relay node and the mobile station are in the boundary region, and

said third relay mode being selected when the position information of the relay mode and the position information of the mobile station indicate that both the relay node and the mobile station are in the center region.

16. A base station in a mobile communication system that provides wireless coverage in a cell, said cell being divided into a center region and a boundary region, said center region being surrounded by said boundary region, said base station comprising:

a transceiver configured to exchange signals with a mobile station via a relay node; and

a controller that selects a relay mode from a plurality of relay modes based on position information of the mobile station and position information of the relay node relative to the boundary region and the center region, each of the plurality of relay modes specifying predetermined wireless resource assignments for communications between the base station and the relay node, and between the relay node and the mobile station,

a first relay mode of the plurality of relay modes specifying combined time division and frequency division multiple wireless resource access in which each of an uplink channel and a downlink channel employ mutually exclusive frequency bands, and

a second relay mode and a third relay mode of the plurality of relay modes use mutually exclusive frequency bands.

17. The base station of claim 16, wherein:

said plurality of relay modes respectively define wireless resources and times to be used when providing an access link from the mobile station to the relay node, and a relay link from the relay node to the base station.