WIRELESS SYSTEM

• US 20100035620A1
• Filed: 08/07/2008
• Published: 02/11/2010
• Est. Priority Date: 08/07/2008
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Naden, James Mark, Zhu, Peiying
• Granted Patent: US 8,355,734 B2
• Time in Patent Office: Days
• US Class Current: 455/450
• 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: H04L 27/2627 Modulators
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0041 Frequency-non-contiguous
• CPC Class Codes: H04L 5/0044 allocation of payload
• CPC Class Codes: H04W 16/12 Fixed resource partitioning
• CPC Class Codes: H04W 72/04 Wireless resource allocation
• CPC Class Codes: H04W 72/044 based on the type of the allocated resource
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/27 between access points
• CPC Class Codes: H04W 72/52 based on load
• CPC Class Codes: H04W 84/047 using dedicated repeater stations

Abstract

The capacity of a cellular wireless system is increased by operation of base stations or base station sectors arranged to re-use radio resource elements that are used by neighbouring base stations or base station sectors, in conjunction with operation of relay stations, which are similarly arranged to re-use radio resource elements used by neighbouring relay stations, and where the radio resource elements re-used by the relay stations are different to those used by the base stations. The relay stations provide coverage, particularly in the areas at the boundaries between the areas of coverage of base stations that suffer from interference between signals transmitted from the respective base stations. In addition, the relay stations generally increase the average available carrier to interference ratio compared with a system in which base stations alone are deployed. The scheme for the allocation of radio resource elements ensures in particular that interference is avoided between signals transmitted from a base station and signals transmitted from a relay station in radio resource elements allocated to control data.

Claims

1. A method of allocating radio resource within a frame structure in a cellular wireless network, the network comprising a plurality of base stations and a plurality of relay stations, the frame structure comprising a plurality of first radio resource elements for the communication of control data, the method comprising:

allocating one or more elements of the plurality of first radio resource elements for communication of control data by the base stations; and

allocating one or more different elements of the plurality of first radio resource elements for communication of control data by the relay stations.

2. A method according to claim 1, wherein the frame structure comprises a plurality of second radio resource elements for the communication of payload data, the method comprising;

allocating one or more elements of the plurality of second radio resource elements for communication of payload data by the base stations; and

allocating one or more different elements of the plurality of second radio resource elements for communication of payload data by the relay stations.

3. A method according to claim 1, wherein the radio resource elements are distinguished in time and/or frequency.

4. A method according to claim 1, wherein the wireless cellular network uses orthogonal frequency division multiplexing.

5. A method according to claim 4, in which the allocated radio resource elements are formed from sub-sets of orthogonal frequency division multiplexing subcarriers.

6. A method according to claim 5, in which the sub-sets of orthogonal frequency division multiplexing subcarriers comprise sub-carriers that are not contiguous in frequency.

7. A method according to claim 1, comprising configuring the network such that regions of coverage in which signals transmitted from base stations interfere do not coincide with regions of coverage in which signals transmitted from relay stations interfere.

8. A cellular wireless network comprising a plurality of base stations and a plurality of relay stations, the network being arranged to allocate radio resources within the network in accordance with a frame structure comprising a plurality of first radio resource elements for the transmission of control data,

wherein the base stations are configured so as to transmit control data within one or more elements of the plurality of first radio resource elements and the relay stations are configured so as to transmit control data within one or more different elements of the plurality of first radio resource elements.

9. A cellular wireless network according to claim 8, wherein the frame structure comprises a plurality of second radio resource elements for the communication of payload data,

wherein the base stations are configured so as to transmit payload data within one or more elements of the plurality of second radio resource elements and the relay stations are configured so as to transmit payload data within one or more different elements of the plurality of second radio resource elements.

10. A cellular wireless network according to claim 8 wherein the radio resource elements are distinguished in time and/or frequency.

11. A cellular wireless network according to claim 8 wherein the cellular wireless network uses orthogonal frequency division multiplexing.

12. A cellular wireless network according to claim 11, wherein the allocated radio resource elements are formed from sub-sets of orthogonal frequency division multiplexing subcarriers.

13. A cellular wireless network according to claim 12, in which the sub-sets of orthogonal frequency division multiplexing subcarriers comprise sub-carriers that are not contiguous in frequency.

14. A cellular wireless network according to claim 8, wherein the network is configured such that regions of coverage in which signals transmitted from base stations interfere do not coincide with regions of coverage in which signals transmitted from relay stations interfere.

15. A base station for use in a cellular wireless network, the network comprising a plurality of base stations and a plurality of relay stations, the network being arranged to allocate radio resources within the network to the base stations and the relay stations in accordance with a frame structure, the frame structure comprising a plurality of first radio resource elements for the transmission of control data,

wherein the base station is configured so as to transmit control data within one or more elements of the plurality of first radio resource elements, the one or more elements being different elements from elements allocated to the relay stations.

16. A base station according to claim 15, wherein the frame structure comprises a plurality of second radio resource elements for the communication of payload data,

wherein the base station is configured so as to transmit payload data within one or more elements of the plurality of second radio resource elements, the one or more elements being different elements from elements allocated to the relay stations.

17. A base station according to claim 15 wherein the radio resource elements are distinguished in time and/or frequency.

18. A base station according to claim 15 wherein the cellular wireless network uses orthogonal frequency division multiplexing.

19. A base station according to claim 18, wherein the allocated radio resource elements are formed from sub-sets of orthogonal frequency division multiplexing subcarriers.

20. A base station according to claim 19, in which the sub-sets of orthogonal frequency division multiplexing subcarriers comprise sub-carriers that are not contiguous in frequency.

27. A computer readable medium encoded with computer executable instructions for causing a processor to configure a base station in accordance with claim 15.

21. A relay station for use in a cellular wireless network, the network comprising a plurality of base stations and a plurality of relay stations, the network being arranged to allocate radio resources within the network to the base stations and the relay stations in accordance with a frame structure, the frame structure comprising a plurality of first radio resource elements for the transmission of control data,

wherein the relay station is configured so as to transmit control data within one or more elements of the plurality of first radio resource elements, the one or more elements being different elements from elements allocated to the base stations.

22. A relay station according to claim 21, wherein the frame structure comprises a plurality of second radio resource elements for the communication of payload data,

wherein the relay station is configured so as to transmit payload data within one or more elements of the plurality of second radio resource elements, the one or more elements being different elements from elements allocated to the base stations.

23. A relay station according to claim 21 wherein the radio resource elements are distinguished in time and/or frequency.

24. A relay station according to claim 21 wherein the cellular wireless network uses orthogonal frequency division multiplexing.

25. A relay station according to claim 24, wherein the allocated radio resource elements are formed from sub-sets of orthogonal frequency division multiplexing subcarriers.

26. A relay station according to claim 25, in which the sub-sets of orthogonal frequency division multiplexing subcarriers comprise sub-carriers that are not contiguous in frequency.

28. A computer readable medium encoded with computer executable instructions for causing a processor to configure a relay station in accordance with claim 21.

29. A method of allocating radio resource within a frame structure in a cellular wireless network operating within a frequency band, the network comprising a user equipment terminal, a plurality of nodes of a first type and a plurality of nodes of a second type, different from the first type, the frame structure comprising a plurality of first timeslots for the transmission of control data and a plurality of second timeslots for the transmission of payload data, the method comprising:

configuring the nodes of the first type so as to transmit control data within a said first timeslot at first selected frequencies; and

configuring the nodes of the second type so as to transmit control data within said first timeslot at second selected frequencies,

wherein said first selected frequencies are different to said second selected frequencies, thereby enabling reception of control data from a node of the first type and from a node of the second type at the user equipment terminal within said first timeslot.

30. A method according to claim 29 comprising:

configuring the nodes of the first type so as to transmit payload data within a said second timeslot at third selected frequencies; and

configuring the nodes of the second type so as to transmit payload data within said second timeslot at fourth selected frequencies,

wherein said third selected frequencies are different to said fourth selected frequencies, thereby enabling reception of payload data from nodes of the first and second types within said second timeslot at the user equipment terminal.

31. The method of claim 30, comprising configuring the nodes of the first type and the nodes of the second type such that the first selected frequencies are different to the third selected frequencies and the second selected frequencies are different from the fourth selected frequencies.

32. The method of claim 29, comprising operating the wireless cellular network using orthogonal frequency division multiplexing.

33. The method of claim 32, in which the selected frequencies each comprise sub-sets of orthogonal frequency division multiplexing subcarriers.

34. The method of claim 33, in which the sub-sets of orthogonal frequency division multiplexing subcarriers comprise sub-carriers that are not contiguous in frequency.

35. The method of claim 29, comprising operating a node of the first type at a first power level and operating a node of the second type at a second power, wherein the first power level is higher than the second power level.

36. The method of claim 35, comprising configuring a node of the first type as a base station and a node of the second type as a relay station.

37. The method of claim 29, comprising transmitting back haul data from a node of the second type to a node of the first type by use of whichever frequencies are operated by a cellular wireless network corresponding to said node of the first type.

38. A method according to claim 29, comprising configuring the network such that regions of coverage in which signals from nodes of a first type interfere do not coincide with regions of coverage in which signals from nodes of a second type interfere.