Communication system

• US 20080009243A1
• Filed: 06/15/2006
• Published: 01/10/2008
• Est. Priority Date: 06/17/2005
• Status: Abandoned Application

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Hart, Michael
• Application Number:
  US11/453,055
• Publication Number:
  US 20080009243A1
• Time in Patent Office: Days
• US Class Current: 455/067.13
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04B 17/336 Signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR]
• CPC Class Codes: H04B 7/2606 Arrangements for base station coverage control, e.g. by using relays in tunnels
• CPC Class Codes: H04W 52/46 in multi hop networks, e.g. wireless relay networks
• CPC Class Codes: H04W 88/04 adapted for relaying to or from another terminal or user

Abstract

The present application relates to a wireless communication system and related methods and apparatuses for transmitting a signal from a source apparatus to a destination apparatus, via at least one intermediate apparatus. In particular, the present invention relates to techniques which seek to improve the throughput of data in multi-hop communication systems.

Claims

1. A communication system comprising a source apparatus, a destination apparatus and at least one intermediate apparatus, wherein the source apparatus and the or each intermediate apparatus each comprise a transmitter, which transmits a communication signal or a signal derived therefrom, in a communication direction towards said destination apparatus, and wherein the destination apparatus and the, or each, intermediate apparatus each comprise a receiver, which receives said communication signal, or a signal derived therefrom, wherein said communication system comprises a determining unit which determines a measure of, or a change in a measure of, the resource allocated to one or more of said transmitters that will tend to substantially attain or maintain a balance between:

i) a measure of the quality of the communication signal received at the destination apparatus; and

ii) measure of the quality of the communication signal received at the, or each, intermediate apparatus.

2. A communication system as claimed in claim 1, further comprising an indicator derivation unit which derives one or more indicators of the quality of a communication signal received at the destination apparatus or at the, or one of the intermediate apparatus(es), the system further comprising:

i) an indicator deviation detection unit which detects a deviation in an indicator derived for the destination apparatus and/or in an indicator derived for the, or one of the, intermediate apparatus(es) from a desired value, wherein said determining unit which, following the detection of such a deviation, determines a measure of, or a change in a measure of, a resource allocated to one or more of the transmitters that will tend to bring the indicator derived for said destination apparatus and/or for the intermediate apparatus, to said desired value.

3. A communication system as claimed in claim 2, wherein the determining unit, following the detection of a change in one said indicator derived for the destination apparatus, to i) determine a measure of, or a change in a measure of, a resource allocated to the transmitter of the intermediate apparatus from which said destination apparatus is operable to receive the communication signal, or ii) determine a measure of, or a change in a measure of, a resource allocated to the transmitter of the, or each, intermediate apparatus and the source apparatus that will tend to bring said indicator to said desired value.

4. A communication system as claimed in claim 2, wherein said determining unit comprises a first calculation unit which, following detection of a deviation from said desired value, calculates a new resource allocation for the transmitter of the intermediate apparatus or for at least one of the intermediate apparatuses, that will tend to tend to bring the said indicator to said desired value.

5. A communication system as claimed in claim 2, further comprising i) imbalance detection unit which detects an imbalance between one said indicator derived for each of at least two of:

the destination apparatus and the, or each, intermediate apparatus;

wherein said determining unit, following the detection of such an imbalance, determines a measure of, or a change in a measure of, a resource allocated to the transmitter of the source apparatus and/or to the transmitter of the, or at least one of the, intermediate apparatus(es) that will tend to substantially reduce said imbalance.

6. A communication system as claimed in claim 5, wherein said determining unit comprises a second calculation unit which, following the detection of such an imbalance, calculates a new resource allocation for the source apparatus and/or a new resource allocation for at least one of the intermediate apparatuses that will tend to substantially reduce said imbalance.

7. A communication system as claimed in claim 1, further comprising indicator derivation unit which derives one or more indicators of the quality of a communication signal respectively received at the destination apparatus, or at the or each intermediate apparatus the system further comprising:

i) an imbalance detection unit which detects an imbalance between one said indicator derived for each of at least two of;

the destination apparatus and the, or each, intermediate apparatus, wherein said determining unit, following the detection of such an imbalance, determines a measure of, or a change in a measure of, a resource allocated to the transmitter of said source apparatus and/or to the transmitter of at least one of the intermediate apparatuses, that will tend to substantially reduce said imbalance.

8. A communication system as claimed in claim 7, wherein said determining unit comprises a calculation unit which, following the detection of such an imbalance, calculates a new resource allocation for the source apparatus and/or for at least one of the intermediate apparatuses that will tend to substantially reduce said imbalance.

9. A communication system as claimed in claim 2, wherein said indicator derivation unit derives an indicator of a measure of the strength of a communication signal received by one or more of said receivers.

10. A communication system as claimed in claim 2, wherein said indicator derivation unit derives an indicator of a measure of the signal-to-interference plus noise ratio (SINR) of a communication signal received by one or more of said receivers.

11. A communication system as claimed in claim 2, wherein said indicator derivation unit derives an indicator of a measure of the variation of the quality of a communication signal received by one or more of said receivers from a target received signal quality.

12. A communication system as claimed in claim 2, wherein said indicator derivation unit derives an indicator of a measure of the quality of service (QoS) experienced by one or more of said receivers.

13. A communication system as claimed in claim 1, wherein the determining unit determines the transmit power allocated to one or more of the transmitters or the change in the transmit power allocated to one or more of the transmitters.

14. A communication system as claimed in claim 1, wherein the determining unit determines the bandwidth allocated to one or more of the transmitters or a change in the bandwidth allocated to one or more of the transmitters.

15. A communication system as claimed in claim 1, further comprising an indicator derivation unit which derives an indicator of the quality of service (QoS) experienced by one or more of said receivers, and wherein said determining unit determines a measure of, or a change in a measure of, the bandwidth allocated to one or more of said transmitters that will tend to substantially attain or maintain a balance between a measure of the QoS experienced at the destination apparatus and a measure of the QoS experienced at the, at least one of the, intermediate apparatus(es).

16. A communication system as claimed in claim 2, wherein the indicator derivation unit comprises a first indicator derivation unit which derives an indicator of the quality of a communication signal received at the destination apparatus and/or a second indicator derivation unit which derives an indicator of the quality of a communication signal received at the, or at least one of the, intermediate apparatuses.

17. A communication system as claimed in claim 16, wherein the first indicator derivation unit is provided in one of said destination apparatus, said intermediate apparatus(es) or said source apparatus.

18. A communication system as claimed in claim 16, wherein the second indicator derivation unit is provided in one of said destination apparatus, said intermediate apparatus(es) or said source apparatus.

19. A communication system as claimed in claim 1, wherein the source apparatus is part of a base station, the base station transmitting a communication signal, via the or each intermediate apparatus, to the destination apparatus.

20. A communication system as claimed in claim 1, wherein the destination apparatus is part of a base station, the source apparatus transmitting a communication signal, via the or each intermediate apparatus, to the base station.

21. A communication system as claimed in claim 1, further comprising a control unit which, following the determination of a measure of or a change in the measure of the resource allocated to one or more of the transmitters, issues a command to said source apparatus and/or to said intermediate apparatus(es), as the case may be, commanding a change in the resource allocated to the transmitter thereof.

22. A communication system as claimed in claim 21, wherein said control unit is provided in the base station.

23. A communication system as claimed in claim 21, wherein said control unit is provided in the, or at least one of the, intermediate apparatus(es).

50. A computer program which, when loaded into a computer, causes the computer to become the base station of the communication system as claimed in claim 1.

51. A computer program which, when loaded onto a computer, causes the computer to become the intermediate apparatus of the communication system as claimed in claim 1.

52. A computer program which, when loaded into a computer, causes the computer to become a destination apparatus of the communication system as claimed in claim 1.

53. A computer program as clamed in claim 50, carried by a carrier medium.

54. A computer program as claimed in claim 53, wherein said carrier medium is a recording medium.

55. A computer program as claimed in claim 53, wherein said carrier medium is a transmission medium.

24. A method of transmitting a communication signal from a source apparatus to a destination apparatus, via one or more intermediate apparatus, wherein the source apparatus and the or each intermediate apparatus each comprise a transmitter, which operable to transmit a communication signal in a communication direction towards said destination apparatus, and wherein the destination apparatus and the, or each, intermediate apparatus each comprise a receiver, which receives said communication signal, or a signal derived therefrom, the method comprising determining a measure of, or a change in the measure of, the resource allocated to one or more of said transmitters that will tend to substantially attain or maintain a balance between i) a measure of the quality of the communication signal received at the destination apparatus and a ii) measure of the quality of the communication signal received at the, or each, intermediate apparatus.

25. A method as claimed in claim 24, the method further comprising the steps of:

i) deriving one or more indicators of the quality of a communication signal received by one or more of said receivers;

ii) detecting a deviation in the, or one of the, said indicators from a desired value;

iii) determining, following the detection of such a deviation, a measure of, or the change in the measure of, a resource allocated to the source apparatus and/or to the, or at least one of the, intermediate apparatuses, that will tend to bring the said indicator to said desired value.

26. A method as claimed in claim 24, the method further comprising the steps of:

i) deriving one or more indicators of the quality of a communication signal received by one or more of said receivers;

ii) detecting an imbalance between one said indicator derived for each of at least two of;

the destination apparatus and the, or each, intermediate apparatus; and

iii) determining, following the detection of such an imbalance a measure of, or a change in a measure of, a resource allocated to the source apparatus and/or to determine a measure of, or a change in a measure of, a resource allocated to the transmitter of at least one of the intermediate apparatuses, that will tend to substantially reduce said imbalance.

27. A method as claimed in claim 25, wherein said method comprises deriving an indicator of the quality of service (QoS) experienced by said destination apparatus.

28. A method as claimed in claim 27, wherein said step of deriving an indicator of the quality of service experienced by said destination apparatus is carried out in parts associated with the, or one of the, intermediate apparatus(es) or in parts associated with the base station.

29. A method as claimed in claim 25, wherein said method comprises deriving an indicator of the quality of service (QoS) experienced by the, or one of the, intermediate apparatus(es).

30. A method as claimed in claim 29, wherein said step of deriving an indicator of the quality of service experienced by the, or one of the, intermediate apparatus(es) is carried out in parts associated with the base station or in parts associated with the intermediate apparatus.

31. A method as claimed in claim 24, wherein the method comprises determining the bandwidth allocated to one or more of the transmitters or the change in the bandwidth allocated to one or more of the transmitters.

32. A base station comprising a transmitter which transmits a communication signal to a destination apparatus, via at least one intermediate apparatus, the base station comprising a determining unit which determines a measure of, or a change in a measure of, the resource allocated to said base station or to the, or one of the, intermediate apparatuses, that will tend to substantially attain or maintain a balance between:

i) a measure of the quality of the communication signal received at the destination apparatus; and

ii) a measure of the quality of the communication signal received at the, or at least one of the, intermediate apparatus(es).

33. A base station as claimed in claim 32, further comprising an indicator receiving unit which receives indicators of the quality of the communication signal received at said destination apparatus and/or the, or at least one of the, intermediate apparatus(es), and an indicator deviation detection unit which detects a deviation in one said indicator from a desired value, wherein said determining unit, following detection of a deviation in one said indicator from said desired value, determines a measure of, or a change in a measure of, the resource allocated to said base station or to the, or one of the, intermediate apparatuses that will tend to bring said indicator to said desired value.

34. A base station as claimed in claim 32, further comprising a request receiving unit which receives a request for a new resource allocation for the, or one of the, intermediate apparatus(es).

37. A base station as claimed in claim 33, further comprising an imbalance detection unit which detects an imbalance between an indicator derived for each of at least two of:

the destination apparatus and the, or each, intermediate apparatus;

wherein said determining unit, following the detection of such an imbalance, determines a measure of, or a change in a measure of, a resource allocated to the transmitters of the base station and/or at least one of the intermediate apparatuses that will tend to substantially reduce said imbalance.

38. A base station as claimed in claim 33, wherein said determining unit comprises a first calculation unit which, following detection of a deviation in one said indicator from a desired value, calculates the resource to be allocated to said base station or to the, or one of the, intermediate apparatuses that will tend to bring said indicator to said desired value.

39. A base station as claimed in claim 37, wherein said determining unit comprises a second calculation unit which, following detection of an imbalance by said imbalance detection unit, calculates a measure of, or a change in a measure of, a resource allocated to the transmitters of:

the base station and/or at least one of the intermediate apparatuses, that will tend to substantially reduce said imbalance.

35. A base station as claimed in 32, further comprising an indicator derivation unit which derives an indicator of the quality of the communication signal received at said destination apparatus and/or at the, or at least one of one of the, intermediate apparatus(es).

36. A base station as claimed in claim 35, further comprising an indicator deviation detection unit which detects a deviation in one said indicator derived by said indicator derivation unit, from a desired value, wherein said determining unit, following detection of a deviation in one said indicator from a desired value, determines a measure of, or a change in a measure of, the resource allocated to said base station or to the, or one of the, intermediate apparatuses that will tend to bring said indicator to said desired value.

40. A base station which receives, via at least one intermediate apparatus, a communication signal transmitted by a source apparatus, the base station comprising a determining unit which determines a measure of, or a change in a measure of, the resource allocated to said source apparatus or to the, or one of the, intermediate apparatus(es), that will tend to substantially attain or maintain a balance between:

i) a measure of the quality of the communication signal received at the base station; and

ii) a measure of the quality of the communication signal received at the, or at least one of the, intermediate apparatus(es).

41. A base station as claimed in claim 40, further comprising an indicator receiving unit which receives indicators of the quality of the communication signal received at the, or at least one of the, intermediate apparatus(es).

42. A base station as claimed in claim 40, further comprising an indicator derivation unit which derives an indicator of the quality of the communication signal received at said base station and/or at the, or at least one of one of the, intermediate apparatus(es).

43. A base station a claimed in claim 41, further comprising an indicator deviation detection unit which detects a deviation in one said indicator derived by said indicator derivation unit, from a desired value, wherein said determining unit, following detection of a deviation in one said indicator from a desired value, determines a measure of, or a change in a measure of, the resource allocated to said source apparatus or to the, or one of the, intermediate apparatuses that will tend to bring said indicator to said desired value.

44. A base station as claimed in claim 40, further comprising an imbalance detection unit which detects an imbalance between an indicator derived for each of at least two of:

the base station and the, or each, intermediate apparatus;

wherein said determining unit, following the detection of such an imbalance, determines a measure of, or a change in a measure of, a resource allocated to the transmitters of the source apparatus and/or at least one of the intermediate apparatuses that will tend to substantially reduce said imbalance.

45. A base station as claimed in claim 43, wherein said determining unit comprises a first calculation unit which, following detection of a deviation in one said indicator from a desired value, calculates the resource to be allocated to said source apparatus or to the, or one of the, intermediate apparatuses that will tend to bring said indicator to said desired value.

46. A base station as claimed in claim 44, wherein said determining unit comprises a second calculation unit which, following detection of an imbalance by said imbalance detection unit, calculates a measure of, or a change in a measure of, a resource allocated to the transmitters of:

the source apparatus and/or at least one of the intermediate apparatuses, that will tend to substantially reduce said imbalance.

47. A destination apparatus for receiving a signal from a source apparatus, via an intermediate apparatus, in a multi-hop communication system, the destination apparatus, comprising:

i) an indicator derivation unit which derives one or more indicators of a quality of a communication signal received at the destination apparatus; and

ii) an indicator deviation detection unit which detects a deviation in one said indicator from a desired value.

48. An intermediate apparatus for use in a multi-hop communication system, said intermediate apparatus comprising a transmitter and a receiver, said intermediate apparatus receiving a communication signal from a source apparatus or from a previous intermediate apparatus in a communication direction, and transmitting said communication signal or a signal derived therefrom, to a destination apparatus or a subsequent intermediate apparatus in a communication direction, said intermediate apparatus further comprising:

a determining unit which determines a measure of, or a change in a measure of, the resource allocated to;

said transmitter of the intermediate apparatus; and

/or a transmitter of said source apparatus; and

/or a transmitter of said previous intermediate apparatus, and/or a transmitter of a subsequent intermediate apparatus, that will tend to substantially attain or maintain a balance between a measure of the quality of the communication signal received at, at least two of;

a receiver of the destination apparatus;

the receiver of the intermediate apparatus;

a receiver of a previous intermediate apparatus; and

a receiver of a subsequent intermediate apparatus.

49. An intermediate apparatus as claimed in claim 48, further comprising an indicator derivation unit which derives an indicator of the quality of the communication signal received at any one of said receivers.