Communication Systems

• US 20080107073A1
• Filed: 09/17/2007
• Published: 05/08/2008
• Est. Priority Date: 11/06/2006
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Hart, Michael John Beems, Zhou, Yuefeng
• Granted Patent: US 8,634,343 B2
• Time in Patent Office: Days
• US Class Current: 370/330
• CPC Class Codes: H04L 25/20 Repeater circuits; Relay circuits
• CPC Class Codes: H04L 27/2602 Signal structure
• CPC Class Codes: H04L 5/14 Two-way operation using the same type of signal, i.e. duplex

Abstract

A transmission method for use in a multi-hop wireless communication system is provided. The system includes a source apparatus, a destination apparatus and one or more intermediate apparatuses. The system has access to a time-frequency format for use in assigning available transmission frequency bandwidth during a discrete transmission interval, said format defining a plurality of transmission windows within such an interval, each window occupying a part of that interval and having a frequency bandwidth profile within said available transmission frequency bandwidth over its part of that interval, each said window being assignable for such a transmission interval to one or more of said apparatuses for use in transmission. The transmission windows include an initial control window for control information transmission and a relay window for transmission by the source apparatus to at least one of said intermediate apparatuses. The relay window is defined as the last window in the discrete transmission interval assignable to the source apparatus for transmission. The method includes employing said format for such a transmission interval to assign the control window to the source apparatus and to the intermediate apparatus for control information transmission and to assign the relay window to the source apparatus for data transmission to a particular one of said intermediate apparatuses. In this way, at least one window between the preamble window and the relay window can be assigned to the particular intermediate apparatus for data transmission. The method also includes transmitting in the transmission interval.

Claims

1. A transmission method for use in a multi-hop wireless communication system, the system comprising a source apparatus, a destination apparatus and one or more intermediate apparatuses, said source apparatus being operable to transmit along a series of links forming a communication path extending from the source apparatus to the destination apparatus via the intermediate apparatus, and the intermediate apparatus being operable to receive from a previous apparatus along the path and to transmit to a subsequent apparatus along the path, the system having access to a time-frequency format for use in assigning available transmission frequency bandwidth during a discrete transmission interval, said format defining a plurality of transmission windows within such an interval, each window occupying a part of that interval and having a frequency bandwidth profile within said available transmission frequency bandwidth over its part of that interval, each said window being assignable for such a transmission interval to one or more of said apparatuses for use in transmission, the transmission windows including an initial control window for control information transmission, and a relay window for transmission by the source apparatus to the sole intermediate apparatus or to at least one of the intermediate apparatuses, the relay window being defined as the last window in the discrete transmission interval assignable to the source apparatus for transmission, the method comprising:

employing said format for such a transmission interval to assign the control window to the source apparatus and to the intermediate apparatus for control information transmission; and

to assign the relay window to the source apparatus for data transmission to the sole intermediate apparatus or to a particular one of said intermediate apparatuses;

so that at least one window between the control window and the relay window can be assigned to the sole intermediate apparatus or to the particular intermediate apparatus for data transmission; and

transmitting in the transmission interval.

2. The transmission method according to claim 1, wherein the format further defines an intermediate window between the control window and the relay window, and the method further comprises:

employing said format for the transmission interval to assign the intermediate window to the particular or sole intermediate apparatus for data transmission.

3. The transmission method according to claim 1, wherein the system comprises at least a further destination apparatus, the format additionally defining a source access window between the control window and the relay window for transmission to such a further destination apparatus,

further comprising assigning the source access window to said source apparatus to allow transmission of data directly to such a further destination apparatus along a corresponding single link forming a direct communication path.

4. The transmission method according to claim 2, wherein the source access window encompasses the intermediate window.

5. The transmission method according to claim 2, wherein the control window, source access window and relay window together occupy the whole or substantially the whole of a transmission interval.

6. The transmission method according to claim 2, wherein the system comprises a single intermediate apparatus and the intermediate window is for transmission to the destination apparatus.

7. The transmission method according to claim 2, wherein the system comprises at least two said intermediate apparatuses and the format defines two constituent intermediate windows forming the intermediate window:

an intermediate link window for transmission from the particular intermediate apparatus to the subsequent intermediate apparatus along the communication path and an intermediate access window for transmission from the subsequent intermediate apparatus to the destination apparatus, the method further comprising;

employing said format for the transmission interval to assign the intermediate access and intermediate link windows to the particular and subsequent intermediate apparatuses for data transmission.

9. The transmission method according to claim 7, wherein the system comprises at least three said intermediate apparatuses, the particular and subsequent intermediate apparatuses being the first and second intermediate apparatuses along the communication path, the intermediate access window encompassing a further constituent intermediate access window and a further constituent intermediate link window both for transmission by the third intermediate apparatus in the communications path;

the method comprising;

employing said format to assign the constituent intermediate windows to the intermediate apparatuses for data transmission.

10. The transmission method according to claim 7, wherein the system comprises at least three said intermediate apparatuses, the particular and subsequent intermediate apparatuses being the first and second intermediate apparatuses along the communication path and the format further defines an extra window after the intermediate window for the second intermediate apparatus to transmit to the third intermediate apparatus along the communication path;

the method further comprising;

employing said format to assign the extra transmission window to the second intermediate apparatus.

11. The transmission method according to claim 10, wherein the system comprises at least four said intermediate apparatuses, the method further comprising employing said format to assign the intermediate link window to the first and third intermediate apparatuses and assign the extra window to the second and fourth intermediate apparatuses.

12. The transmission method according to claim 10, wherein the relay window encompasses the extra window.

13. The transmission method according to claim 2, wherein each window assigned to an intermediate apparatus comprises at least two component transmission windows, one of those component transmission windows being for transmission of intermediate apparatus control information, and one of those component transmission windows being for transmission of data.

14. The transmission method according to claim 13, wherein each window assigned to an intermediate apparatus comprises three component transmission windows, one of those component transmission windows being for transmission of a transmission introduction sequence for that intermediate apparatus.

15. The transmission method according to claim 13, wherein the component transmission window for transmission of intermediate apparatus control information indicates format information relating to the time position of the intermediate apparatus control information or the time position of the transmission introduction sequence respectively in a subsequent transmission interval.

16. The transmission method according to claim 13, wherein the component transmission window for transmission of intermediate apparatus control information indicates format information relating to encoding and/or modulation of the intermediate apparatus control information and/or transmission introduction sequence in a subsequent transmission interval.

17. The transmission method according to claim 1, wherein the control window comprises at least two component windows, one of those component windows being for transmission of a preamble and another of those component windows being for transmission of other control information including format information.

18. The transmission method according to claim 17, wherein each window assigned to an intermediate apparatus comprises at least two component transmission windows, one of those component transmission windows being for transmission of intermediate apparatus control information, and one of those component transmission windows being for transmission of data and wherein the format information relates to the time position of the intermediate apparatus control information or the time position of transmission introduction sequence respectively in the transmission interval.

19. The transmission method according to claim 17, wherein each window assigned to an intermediate apparatus comprises at least two component transmission windows, one of those component transmission windows being for transmission of intermediate apparatus control information, and one of those component transmission windows being for transmission of data and wherein the format information relates to encoding and/or modulation of the intermediate apparatus control information and/or transmission introduction sequence in the transmission interval.

20. The transmission method according to claim 3, wherein transmission time available in the format is shared between the source access window and the relay window, further comprising, prior to assigning windows for transmission, monitoring the quality of service provided by the source access and relay windows and adjusting the time position of a division between the source access and relay window interval parts accordingly.

21. The transmission method according to claim 20, further comprising, after adjusting the division position, checking whether the adjustment has improved quality of service in the window having the enlarged interval part and blocking further adjustment in that direction if there has been no such improvement.

22. The transmission method according to claim 21, further comprising unblocking the further adjustment if the division is subsequently moved in the other direction.

23. The transmission method according to claim 1, wherein the frequency bandwidth profiles of at least two of said transmission windows encompass a common part of the available transmission frequency bandwidth.

24. The transmission method according to claim 1, wherein the frequency bandwidth profiles of at least two said transmission windows extend over substantially the entire transmission frequency bandwidth for the respective interval parts.

25. The transmission method according to claim 1, comprising employing a space division multiple access technique in one or more of said transmission windows of said transmission interval(s), as the case may be.

26. The transmission method according to claim 1, wherein the time-frequency format is a format for a downlink or uplink sub-frame in a time-division-duplex communication system.

27. The transmission method according to claim 1, wherein said system is an OFDM or OFDMA system, and wherein the time-frequency format is a format for an OFDM or OFDMA downlink or uplink sub-frame of an OFDM or OFDMA time-division-duplex frame.

28. The transmission method according to claim 1, wherein each said discrete transmission interval is a sub-frame period.

29. The transmission method according to claim 1, wherein each said transmission window comprises a region in an OFDM or OFDMA frame structure.

30. The transmission method according to claim 1, wherein each said transmission window comprises a zone in an OFDM or OFDMA frame structure.

31. The transmission method according to claim 1, wherein said source apparatus is a base station.

32. The transmission method according to claim 1, wherein said source apparatus is a user terminal.

33. The transmission method according to claim 1, wherein the destination apparatus is a base station.

34. The transmission method according to claim 1, wherein the destination apparatus is a user terminal.

35. The transmission method according to claim 1, wherein the intermediate apparatus is a relay station.

8. The transmission method according to claim 8, wherein the system comprises at least a further destination apparatus and the intermediate access window is also for transmission from the particular intermediate apparatus to a further destination apparatus.

36. A multi-hop wireless communication system, the system comprising:

a source apparatus, a destination apparatus and one or more intermediate apparatuses, said source apparatus being operable to transmit along a series of links forming a communication path extending from the source apparatus to the destination apparatus via the intermediate apparatus, and the intermediate apparatus being operable to receive from a previous apparatus along the path and to transmit to a subsequent apparatus along the path;

a format-accessor operable to access a time-frequency format for use in assigning available transmission frequency bandwidth during a discrete transmission interval, said format defining a plurality of transmission windows within such an interval, each window occupying a part of that interval and having a frequency bandwidth profile within said available transmission frequency bandwidth over its part of that interval, each said window being assignable for such a transmission interval to at least one of said apparatuses for use in transmission, the transmission windows including an initial control window for control information transmission, and a relay window for transmission by the source apparatus to the sole intermediate apparatus or to at least one of said intermediate apparatuses, the relay window being defined as the last window in the discrete transmission interval assignable to the source apparatus for transmission;

an assignor operable to employ said format for such a transmission interval to assign the control window to the source apparatus and to the intermediate apparatus for control information transmission; and

to assign the relay window to the source apparatus for data transmission to the sole intermediate apparatus or to a particular one of said intermediate apparatuses;

so that at least one window between the control window and the relay window can be assigned to the sole intermediate apparatus or to the particular intermediate apparatus for data transmission; and

a transmitter operable to transmit in the transmission interval.

37. Software embodied on a computer-readable medium and operable, when executed on one or more computing devices of a multi-hop wireless communication system, to cause the system to carry out a transmission method, the system comprising a source apparatus, a destination apparatus and one or more intermediate apparatuses, said source apparatus being operable to transmit along a series of links forming a communication path extending from the source apparatus to the destination apparatus via the intermediate apparatus, and the intermediate apparatus being operable to receive from a previous apparatus along the path and to transmit to a subsequent apparatus along the path, the system having access to a time-frequency format for use in assigning available transmission frequency bandwidth during a discrete transmission interval, said format defining a plurality of transmission windows within such an interval, each window occupying a part of that interval and having a frequency bandwidth profile within said available transmission frequency bandwidth over its part of that interval, each said window being assignable for such a transmission interval to at least one of said apparatuses for use in transmission, the transmission windows including an initial control window for control information transmission, and a relay window for transmission by the source apparatus to the sole intermediate apparatus or to at least one of said intermediate apparatuses, the relay window being defined as the last window in the discrete transmission interval assignable to the source apparatus for transmission, the method comprising:

employing said format for such a transmission interval to assign the control window to the source apparatus and to the intermediate apparatus for control information transmission; and

to assign the relay window to the source apparatus for data transmission to the sole intermediate apparatus or to a particular one of said intermediate apparatuses;

so that at least one window between the control window and the relay window can be assigned to the sole intermediate apparatus or to the particular intermediate apparatus for data transmission; and

transmitting in the transmission interval.