METHOD AND APPARATUS FOR CONTROLLING A RELAY STATION IN A MULTI-HOP RELAY NETWORK

• US 20090075588A1
• Filed: 08/14/2008
• Published: 03/19/2009
• Est. Priority Date: 09/19/2007
• Status: Active Grant

• Current Assignee: Socionext Inc.
• Original Assignee: Fujitsu Limited
• Inventors: Nakamura, Michiharu, Viorel, Dorin, ZHU, Chenxi
• Granted Patent: US 8,867,983 B2
• Time in Patent Office: Days
• US Class Current: 455/18
• CPC Class Codes: H04B 7/155 Ground-based stations H04B7/204 takes precedence
• CPC Class Codes: H04B 7/2606 Arrangements for base station coverage control, e.g. by using relays in tunnels
• CPC Class Codes: H04L 27/2655 Synchronisation arrangements
• CPC Class Codes: H04W 72/535 based on resource usage policies
• CPC Class Codes: H04W 84/047 using dedicated repeater stations

Abstract

A method of controlling a relay station in a cell of a multi-hop relay network in accordance with a one-way propagation delay between a base station in the cell and the relay station. A relay station in a cell of a multi-hop relay network including means for controlling the signal flow between the relay station and the various other stations in the cell in accordance with a one-way propagation delay between a base station in the cell and the relay station.

Claims

1. A method, comprising:

during a downlink sub-frame, controlling a relay station in a cell of a multi-hop relay network to end a transmit zone, in which the relay station transmits signals to one or more slave stations in the cell, in accordance with a one-way propagation delay between a base station in the cell and the relay station.

2. The method according to claim 1, further comprising:

during the downlink sub-frame, controlling the relay station to end the transmit zone at least a first predetermined period of time before the relay station begins a receive zone, in which the relay station receives signals from a master station in the cell.

3. The method according to claim 2, wherein, when a time required for a physical layer of the relay station to transition from a transmit state, in which the relay station is capable of transmitting signals, to a receive state, in which the relay station is capable of receiving signals, is greater than the one-way propagation delay between the base station and the relay station, the first predetermined period of time is equal to the time required for the physical layer of the relay station to transition from the transmit state to the receive state minus the one-way propagation delay between the base station and the relay station.

4. The method according to claim 3, further comprising:

during the downlink sub-frame, controlling the relay station to start the transmit zone in accordance with the one-way propagation delay between the base station in the cell and the relay station.

5. The method according to claim 4, further comprising:

during the downlink sub-frame, preventing the relay station from starting the transmit zone until at least a second predetermined period of time has passed since the relay station was in the receive zone.

6. The method according to claim 5, wherein, when the time required for the physical layer of the relay station to transition from the transmit state to the receive state is greater than the one-way propagation delay between the base station and the relay station, the second predetermined period of time is equal to a time required for the physical layer of the relay station to transition from the receive state to the transmit state plus the one-way propagation delay between the base station and the relay station.

7. The method according to claim 6, wherein the first predetermined period of time is measured as a number of time symbols and the relay station ends the transmit zone at a time symbol immediately after the first predetermined period of time has passed.

8. The method according to claim 7, wherein the second predetermined period of time is measured as a number of time symbols and the relay station is prevented from starting the transmit zone until a time symbol immediately after the second predetermined period of time has passed.

9. The method according to claim 2, wherein, when a time required for a physical layer of the relay station to transition from a transmit state, in which the relay station is capable of transmitting signals, to a receive state, in which the relay station is capable of receiving signals, is less than the one-way propagation delay between the base station and the relay station, the first predetermined period of time is equal to zero.

10. The method according to claim 9, further comprising:

during the downlink sub-frame, controlling the relay station to start the transmit zone in accordance with the one-way propagation delay between the base station in the cell and the relay station.

11. The method according to claim 10, further comprising:

during the downlink sub-frame, preventing the relay station from starting the transmit zone until at least a second predetermined period of time has passed since the relay station was in the receive zone.

12. The method according to claim 11, wherein, when the time required for the physical layer of the relay station to transition from the transmit state to the receive state is less than the maximal one-way propagation delay between the base station and the station within the cell that is the farthest away from the base station, the second predetermined period of time is equal to a time required for the physical layer of the relay station to transition from the receive state to the transmit state plus the one-way propagation delay between the base station and the relay station.

13. The method according to claim 12, wherein the first predetermined period of time is measured as a number of time symbols and the relay station is prevented from starting the transmit zone until a time symbol immediately after the second predetermined period of time has passed.

15. The method according to claim 13, wherein the time R_TTG is measured as a number of time symbols and the relay station ends the transmit zone at a time symbol immediately after the time R_TTG has passed.

16. The method according to claim 15, wherein the time R_RTG is measured as a number of time symbols and the relay station is prevented from starting the transmit zone until a time symbol immediately after the time R_RTG has passed.

14. A method, comprising:

during a downlink sub-frame, controlling a relay station in a cell of a multi-hop relay network to switch between a transmit zone, in which the relay station transmits signals to one or more slave stations in the cell, and a receive zone, in which the relay station receives signals from a master station in the cell, according to R_TTG=RS_HW_TTG−

D and R_RTG=RS_HW_RTG+D, when RS_HW_TTG>

D, wherein

R_TTG is a time required to pass after the relay station ends the transmit zone before the relay station can start the receive zone,

RS_HW_TTG is a time required for a physical layer of the relay station to transition from a transmit state, in which the relay station is capable of transmitting signals, to a receive state, in which the relay station is capable of receiving signals,

D is a one-way propagation delay time between a base station in the cell and the relay station,

R_RTG is a time required to pass after the relay station ends the receive zone before the relay station can start the transmit zone, and

RS_HW_RTG is a time required for a physical layer of the relay station to transition from the receive state to the transmit state.

17. A method, comprising:

during a downlink sub-frame, controlling a relay station in a cell of a multi-hop relay network to switch between a transmit zone, in which the relay station transmits signals to one or more slave stations in the cell, and a receive zone, in which the relay station receives signals from a master station in the cell, according to R_TTG=0 and R_RTG=RS_HW_RTG+D, when RS_HW_TTG<

D, wherein

R_TTG is a time required to pass after the relay station ends the transmit zone before the relay station can start the receive zone,

D is a one-way propagation delay time between a base station in the cell and the relay station,

R_RTG is a time required to pass after the relay station ends the receive zone before the relay station can start the transmit zone,

RS_HW_RTG is a time required for a physical layer of the relay station to transition from a receive state, in which the relay station is capable of receiving signals, to a transmit state, in which the relay station is capable of transmitting signals, and

RS_HW_TTG is a time required for a physical layer of the relay station to transition from the transmit state to the receive state.

18. The method according to claim 17, wherein the time R_RTG is measured as a number of time symbols and the relay station is prevented from starting the transmit zone until a time symbol immediately after the time R_RTG has passed.

19. A method, comprising:

during an uplink sub-frame, controlling a relay station in a cell of a multi-hop relay network to end a receive zone, in which the relay station receives signals from one or more slave stations in the cell, in accordance with a one-way propagation delay between a base station in the cell and the relay station.

20. The method according to claim 19, further comprising:

during the uplink sub-frame, controlling the relay station to end the receive zone at least a first predetermined period of time before the relay station begins a transmit zone, in which the relay station transmits signals to a master station in the cell.

21. The method according to claim 20, wherein, when a time required for a physical layer of the relay station to transition from a transmit state, in which the relay station is capable of transmitting signals, to a receive state, in which the relay station is capable of receiving signals, is greater than the one-way propagation delay between the base station and the relay station, the first predetermined period of time is equal to a time required for the physical layer of the relay station to transition from the receive state to the transmit state plus the one-way propagation delay between the base station and the relay station.

22. The method according to claim 21, further comprising:

during the uplink sub-frame, controlling the relay station to start the receive zone in accordance with the one-way propagation delay between the base station in the cell and the relay station.

23. The method according to claim 22, further comprising:

during the uplink sub-frame, preventing the relay station from starting the receive zone until at least a second predetermined period of time has passed since the relay station was in the transmit zone.

24. The method according to claim 23, wherein, when the time required for the physical layer of the relay station to transition from the transmit state to the receive state is greater than the one-way propagation delay between the base station and the relay station, the second predetermined period of time is equal to a time required for the physical layer of the relay station to transition from the transmit state to the receive state minus the one-way propagation delay between the base station and the relay station.

25. The method according to claim 24, wherein the first predetermined period of time is measured as a number of time symbols and the relay station ends the receive zone at a time symbol immediately after the first predetermined period of time has passed.

26. The method according to claim 25, wherein the second predetermined period of time is measured as a number of time symbols and the relay station is prevented from starting the receive zone until a time symbol immediately after the second predetermined period of time has passed.

27. The method according to claim 20, wherein, when a time required for a physical layer of the relay station to transition from a transmit state, in which the relay station is capable of transmitting signals, to a receive state, in which the relay station is capable of receiving signals, is less than the one-way propagation delay between the base station and the relay station, the first predetermined period of time is equal to a time required for the physical layer of the relay station to transition from the receive state to the transmit state plus the one-way propagation delay between the base station and the relay station.

28. The method according to claim 27, further comprising:

during the uplink sub-frame, controlling the relay station to start the transmit zone in accordance with the one-way propagation delay between the base station in the cell and the relay station.

29. The method according to claim 28, further comprising:

during the uplink sub-frame, preventing the relay station from starting the transmit zone until at least a second predetermined period of time has passed since the relay station was in the receive zone.

30. The method according to claim 29, wherein, when the time required for the physical layer of the relay station to transition from the transmit state to the receive state is less than the one-way propagation delay between the base station and the relay station, the second predetermined period of time is equal to zero.

31. The method according to claim 30, wherein the first predetermined period of time is measured as a number of time symbols and the relay station ends the receive zone at a time symbol immediately after the first predetermined period of time has passed.

32. A method, comprising:

during an uplink sub-frame, controlling a relay station in a cell of a multi-hop relay network to switch between a transmit zone, in which the relay station transmits signals to a master station in the cell, and a receive zone, in which the relay station receives signals from one or more slave stations in the cell, according to UL_R_RTG=D+RS_HW_RTG and UL_R_TTG=RS_HW_TTG−

D, when RS_HW_TTG>

D, wherein

UL_R_RTG is a time required to pass after the relay station ends the receive zone before the relay station can start the transmit zone,

D is a one-way propagation delay time between a base station in the cell and the relay station,

RS_HW_RTG is a time required for a physical layer of the relay station to transition from a receive state, in which the relay station is capable of receiving signals transmit state, to a transmit state, in which the relay station is capable of transmitting signals,

UL_R_TTG is a time required to pass after the relay station ends the transmit zone before the relay station can start the receive zone, and

RS_HW_TTG is a time required for a physical layer of the relay station to transition from the transmit state to the receive state.

33. The method according to claim 32, wherein the relay station starts the transmit zone at a time symbol immediately after the time UL_R_RTG has passed.

34. The method according to claim 33, wherein the time UL_R_TTG is measured as a number of time symbols and the relay station is prevented from starting the receive zone until a time symbol immediately after the time UL_R_TTG has passed.

35. A method, comprising:

during an uplink sub-frame, controlling a relay station in a cell of a multi-hop relay network to switch between a transmit zone, in which the relay station transmits signals to a master station in the cell, and a receive zone, in which the relay station receives signals from one or more slave stations in the cell, according to UL_R_RTG=D+RS_HW_RTG and UL_R_TTG=0, when RS_HW_TTG<

D, wherein

UL_R_RTG is a time required to pass after the relay station ends the receive zone before the relay station can start the transmit zone,

D is a one-way propagation delay time between a base station in the cell and the relay station,

RS_HW_RTG is a time required for a physical layer of the relay station to transition from a receive state, in which the relay station is capable of receiving signals transmit state, to a transmit state, in which the relay station is capable of transmitting signals,

UL_R_TTG is a time required to pass after the relay station ends the transmit zone before the relay station can start the receive zone, and

RS_HW_TTG is a time required for a physical layer of the relay station to transition from the transmit state to the receive state.

36. The method according to claim 35, wherein the time UL_R_RTG is measured as a number of time symbols and the relay station starts the transmit zone at a time symbol immediately after the time UL_R_RTG has passed.

37. A relay station operating in a cell of a multi-hop relay network, comprising:

during the downlink sub-frame, first control means for controlling the relay station to end a transmit zone, in which the relay station transmits signals to one or more slave stations in the cell, at least a first predetermined period of time before the relay station begins a receive zone, in which the relay station receives signals from a master station in the cell;

during the downlink sub-frame, second control means for preventing the relay station from starting the transmit zone until at least a second predetermined period of time has passed since the relay station was in the receive zone, wherein

at least one of the first predetermined period of time and the second predetermined period of time depend on a one-way propagation delay between a base station in the cell and the relay station.

38. The relay station according to claim 37, further comprising:

a transceiver configured to switch between a transmit state, in which the transceiver is capable of transmitting signals, and a receive state, in which the transceiver is capable of receiving signals; and

memory means for storing information related to the first predetermined period of time and the second predetermined period of time.

39. A relay station operating in a cell of a multi-hop relay network, comprising:

during an uplink sub-frame, first control means for controlling the relay station to end a receive zone, in which the relay station receives signals from one or more slave stations in the cell, at least a first predetermined period of time before the relay station begins a transmit zone, in which the relay station transmits signals to a master station in the cell; and

during the uplink sub-frame, second control means preventing the relay station from starting the receive zone until at least a second predetermined period of time has passed since the relay station was in the transmit zone, wherein

at least one of the first predetermined period of time and the second predetermined period of time depend on a one-way propagation delay between a base station in the cell and the relay station.

40. The relay station according to claim 39, further comprising:

a transceiver configured to switch between a transmit state, in which the transceiver is capable of transmitting signals, and a receive state, in which the transceiver is capable of receiving signals; and

memory means for storing information related to the first predetermined period of time and the second predetermined period of time.