MULTI-HOP COMMUNICATIONS IN A WIRELESS NETWORK

• US 20090201907A1
• Filed: 03/10/2009
• Published: 08/13/2009
• Est. Priority Date: 02/09/2004
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Krishnan, Ranganathan, Nanda, Sanjiv
• Granted Patent: US 8,019,351 B2
• Time in Patent Office: Days
• US Class Current: 370/345
• CPC Class Codes: H04W 52/367 Power values between minimum and maximum limits, e.g. dynamic range
• CPC Class Codes: H04W 52/46 in multi hop networks, e.g. wireless relay networks
• CPC Class Codes: H04W 72/1221 based on age of data to be sent
• CPC Class Codes: H04W 72/54 based on quality criteria
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

Systems and techniques are disclosed relating to wireless communications. The systems and techniques involve wireless communications wherein a module or communications device is configured to select first and second terminal pairs, the first terminal pair having a first transmitting terminal and a first receiving terminal, and the second terminal pair having a second transmitting terminal and a second receiving terminal, schedule a first signal transmission from the first transmitting terminal to an intermediate terminal, the first signal transmission being destined for the first receiving terminal, schedule, simultaneously with the first signal transmission, a second signal transmission from the second transmitting terminal to the second receiving terminal, and schedule a power level for each of the first and second signal transmissions that satisfies a target quality parameter for each of the intermediate terminal and the second receiving terminal.

Claims

1. A method of scheduling communications, comprising:

selecting first and second terminal pairs, the first terminal pair having a first transmitting terminal and a first receiving terminal, and the second terminal pair having a second transmitting terminal and a second receiving terminal;

determining an amount of data remaining to be transmitted between the first terminal pair and the second terminal pair and selecting a first data rate for the first terminal pair and a second data rate for the second terminal pairs; and

determining whether a first direct signal transmission from the first transmitting terminal to the first receiving terminal at the first data rate simultaneously with a second direct signal transmission from the second transmitting terminal to the second receiving terminal at the second data rate satisfies a target quality parameter for the first receiving terminal and a target quality parameter for the second receiving terminal, if the target quality parameters for both the first receiving terminal and the second receiving terminal are not satisfied then scheduling a first signal transmission from the first transmitting terminal to an intermediate terminal, the first signal transmission being destined for the first receiving terminal.

2. The method of claim 1, further comprising scheduling, simultaneously with the first signal transmission, a second signal transmission from the second transmitting terminal to the second receiving terminal.

3. The method of claim 1, further comprising scheduling a power level for each of the first and second signal transmissions that satisfies a target quality parameter for the intermediate terminal and the target quality parameter of the second receiving terminal.

4. The method of claim 1, wherein determining whether the first direct signal transmission simultaneously with the second direct signal transmission satisfies the target quality parameters for each of the first and second receiving terminals comprises computing a power level for each of the direct signal transmission.

5. The method of claim 1, wherein determining whether the first direct signal transmission simultaneously with the second direct signal transmission satisfies the target quality parameters for each of the first and second receiving terminals is a function of the distance between the first transmitting terminal and the first receiving terminal and the distance between the first transmitting terminal and the second receiving terminal.

6. The method of claim 1, wherein determining whether the first direct signal transmission simultaneously with the second direct signal transmission satisfies the target quality parameters for each of the first and second receiving terminals is a function of path loss information between the first transmitting terminal and the first receiving terminal and path loss information between the first transmitting terminal and the second receiving terminal.

7. The method of claim 1, wherein the first and second terminal pairs are selected from a piconet of terminals.

8. The method of claim 7, further comprising constructing a piconet topology map, and wherein at least a portion of path loss information is derived from the piconet topology map.

9. The method of claim 1, further comprising selecting a third terminal pair having a third transmitting terminal and a third receiving terminal, and scheduling a third signal transmission therebetween simultaneously with a retransmission of the first signal transmission from the intermediate terminal to the first receiving terminal.

10. The method of claim 9, further comprising scheduling a power level for each of the retransmission of the first signal transmission and the third signal transmission that satisfies a target quality parameter for each of the first and third receiving terminals.

11. The method of claim 1, further comprising scheduling a different spreading code for each of the first and second signal transmissions.

12. The method of claim 1, wherein the parameter comprises a carrier-to-interference ratio.

13. A communications terminal comprising:

a scheduler configured to select a first and a second terminal pair, the first terminal pair having a first transmitting terminal and a first receiving terminal, and the second terminal pair having a second transmitting terminal and a second receiving terminal, to determine an amount of data remaining to be transmitted between the first terminal pair and the second terminal pair and select a first data rate for the first terminal pair and a second data rate for the second terminal pairs, the scheduler further configured to determine whether a first direct signal transmission from the first transmitting terminal to the first receiving terminal at the first data rate simultaneously with a second direct signal transmission from the second transmitting terminal to the second receiving terminal at the second data rate satisfies both a target quality parameter for the first receiving terminal and a target quality parameter for the second receiving terminal, if the target quality parameters for both the first receiving terminal and the second receiving terminal are not satisfied then schedule a first signal transmission from the first transmitting terminal to an intermediate terminal, the first signal transmission being destined for the first receiving terminal.

14. The communications terminal of claim 13, wherein the scheduler is further configured to determine whether the first direct signal transmission simultaneously with the second direct signal transmission satisfies the target quality parameters for each of the first and second receiving terminals comprises computing a power level for each of the direct signal transmission.

15. The communications terminal of claim 13, wherein the scheduler is further configured to determine whether the first direct signal transmission simultaneously with the second direct signal transmission, satisfies the target quality parameters for each of the first and second receiving terminals as a function of the distance between the first transmitting terminal and the first receiving terminal and the distance between the first transmitting terminal and the second receiving terminal.

16. The communications terminal of claim 13, wherein the scheduler is further configured to determine whether the first direct signal transmission simultaneously with the second direct signal transmission satisfies the target quality parameters for each of the first and second receiving terminals as a function of path loss information between the first transmitting terminal and the first receiving terminal and path loss information between the first transmitting terminal and the second receiving terminal.

17. The communications terminal of claim 16, wherein the scheduler is further configured to select the first and second terminal pairs from a piconet of terminals.

18. The communications terminal of claim 17, wherein the scheduler is further configured to construct a piconet topology map, and derive at least a portion of path loss information from the piconet topology map.

19. The communication termination of claim 13, wherein the scheduler is further configured to select a third terminal pair having a third transmitting terminal and a third receiving terminal, and schedule a third signal transmission therebetween simultaneously with a retransmission of the first signal transmission from the intermediate terminal to the first receiving terminal

20. The communications terminal of claim 19, wherein the scheduler is further configured to schedule a power level for each of the retransmission of the first signal transmission and the third signal transmission that satisfies a target quality parameter for each of the first and third receiving terminals.

21. The communications terminal of claim 13, wherein the scheduler is further configured to schedule a different spreading code for each of the first and second signal transmissions.

22. The communications terminal of claim 13, wherein the parameter comprises a carrier-to-interference ratio.

23. The communications terminal of claim 13, further comprising a receiver configured to receive communications from a plurality of terminals and a transmitter configured to transmit communications to the plurality of terminals, the scheduler being communicatively coupled to the receiver and transmitter.

24. The communications terminal of claim 23, further comprising a receiving signal processor configured to despread communications between the receiver and the scheduler, and a transmitting signal processor configured to spread communications between the scheduler and the transmitter.

25. The communications terminal of claim 23, further comprising a plurality of user interfaces communicatively coupled to the receiver and transmitter.

26. The communications terminal of claim 25, further comprising a receiving signal processor configured to despread communications between the receiver and a first one of the user interfaces, and a transmitting signal processor configured to spread communications between a second one of the user interfaces and the transmitter.

27. A communications terminal, comprising:

means for selecting first and second terminal pairs, the first terminal pair having a first transmitting terminal and a first receiving terminal, and the second terminal pair having a second transmitting terminal and a second receiving terminal;

means for determining an amount of data remaining to be transmitted between the first terminal pair and the second terminal pair and selecting a first data rate for the first terminal pair and a second data rate for the second terminal pairs; and

means for determining whether a first direct signal transmission from the first transmitting terminal to the first receiving terminal at the first data rate simultaneously with a second direct signal transmission from the second transmitting terminal to the second receiving terminal at the second data rate satisfies a target quality parameter for the first receiving terminal and a target quality parameter for the second receiving terminal, if the target quality parameters for both the first receiving terminal and the second receiving terminal are not satisfied then scheduling a first signal transmission from the first transmitting terminal to an intermediate terminal, the first signal transmission being destined for the first receiving terminal.

28. Computer readable media embodying a program of instructions executable by a computer processor to perform a method of scheduling communications, the method comprising:

selecting first and second terminal pairs, the first terminal pair having a first transmitting terminal and a first receiving terminal, and the second terminal pair having a second transmitting terminal and a second receiving terminal;

determining an amount of data remaining to be transmitted between the first terminal pair and the second terminal pair and selecting a first data rate for the first terminal pair and a second data rate for the second terminal pairs; and

determining whether a first direct signal transmission from the first transmitting terminal to the first receiving terminal at the first data rate simultaneously with a second direct signal transmission from the second transmitting terminal to the second receiving terminal at the second data rate satisfies a target quality parameter for the first receiving terminal and a target quality parameter for the second receiving terminal, if the target quality parameters for both the first receiving terminal and the second receiving terminal are not satisfied then scheduling a first signal transmission from the first transmitting terminal to an intermediate terminal, the first signal transmission being destined for the first receiving terminal.