Method and apparatus for controlling transmissions of a communications system

• US 6,744,743 B2
• Filed: 10/23/2002
• Issued: 06/01/2004
• Est. Priority Date: 03/30/2000
• Status: Expired due to Term

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Wallace, Mark, Walton, Jay R., Holtzman, Jack, Antonio, Franklin P.
• Primary Examiner(s): Sam, Phirin
• Application Number:
  US10/279,483
• Publication Number:
  US 20030123425A1
• Time in Patent Office: 587 Days
• Field of Search: 370/317, 370/318, 370/321, 370/326, 370/329, 370/336, 370/347, 370/437, 370/442, 370/458, 370/322, 370/341, 370/345, 370/348, 370/431, 370/443, 370/465, 455/13.4, 455/509, 455/447, 455/450
• US Class Current: 370/318
• CPC Class Codes: H04B 17/336 Signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR]
• CPC Class Codes: H04B 17/382 for resource allocation, admission control or handover
• CPC Class Codes: H04W 52/24 using SIR [Signal to Interference Ratio] or other wireless path parameters
• CPC Class Codes: H04W 52/241 taking into account channel quality metrics, e.g. SIR, SNR, CIR, Eb/lo
• CPC Class Codes: H04W 52/244 Interferences in heterogeneous networks, e.g. among macro and femto or pico cells or other sector / system interference [OSI]
• CPC Class Codes: H04W 52/267 taking into account the information rate
• CPC Class Codes: H04W 52/286 during data packet transmission, e.g. high speed packet access [HSPA]
• CPC Class Codes: H04W 52/343 taking into account loading or congestion level
• CPC Class Codes: H04W 52/346 distributing total power among users or channels
• CPC Class Codes: H04W 72/52 based on load
• CPC Class Codes: H04W 72/542 using measured or perceived quality
• CPC Class Codes: H04W 72/569 of the traffic information

Abstract

In some aspects, each cell in the communications system can be designed to operate in accordance with a set of back-off factors that identify the reductions in peak transmit power levels for the channels associated with the back-off factors. The back-off factors are defined to provide the required power to a large percentage of the users while reducing the amount of interference. In some other aspects, the cells operate using an adaptive reuse scheme that allows the cells to efficiently allocate and reallocate the system resources to reflect changes in the system. A reuse scheme is initially defined and resources are allocated to the cells. During operation, changes in the operating conditions of the system are detected and the reuse scheme is redefined as necessary based on the detected changes. In yet other aspects, techniques are provided to efficiency schedule data transmissions and to assign channels to users.

Claims

1. A method for processing a signal to be transmitted from a transmitting entity to a receiving entity, the method comprising:

selecting a transmit channel from at least two transmit channels associated with the transmitting entity, wherein each of the at least two transmit channels has an associated back-off factor and transmit power, and wherein the transmit power for each of the at least two transmit channels is based on the back-off factor for the transmit channel, and wherein the selecting is based on the back-off factor of the selected transmit channel and on at least one attribute associated with the receiving entity; and

assigning the selected transmit channel to the receiving entity.

2. The method of claim 1 wherein each of the at least two transmit channels correspond to a different frequency than the remainder of the at least two transmit channels.

3. The method of claim 1 wherein each of the at least two transmit channels are transmitted at a different time slot than the remainder of the at least two transmit channels.

4. The method of claim 1 further comprising transmitting on each of the at least two transmit channels at a different frequency than the remainder of the at least two transmit channels.

5. The method of claim 1 further comprising transmitting each of the at least two transmit channels at a different time slot than the remainder of the at least two transmit channels.

6. The method of claim 1 wherein the at least one attribute comprises a minimum required link margin, and wherein the selecting is based on which of the at least two transmit channels has a lowest link margin that equals or exceeds the minimum required link margin.

7. The method of claim 6 wherein the selected transmit channel has a lowest link margin that equals or exceeds a required link margin associated with the receiving entity.

8. The method of claim 6 wherein the selecting comprises upgrading the receiving entity to a transmit channel having link margin that is higher than lowest link margin that equals or exceeds a required link margin associated with the receiving entity.

9. The method of claim 1 wherein the at least one attribute comprises a minimum required data rate.

10. The method of claim 1 wherein the at least one attribute comprises a priority level.

11. The method of claim 1 wherein the at least one attribute comprises an outage probability.

12. The method of claim 1 wherein the at least one attribute comprises a carrier-to-noise-plus-interference level.

13. The method of claim 1 wherein the selecting is further based on a probability that a second transmitting entity will transmit on a particular transmit channel at the same time as the transmitting entity.

14. The method of claim 1 further comprising transmitting the at least two transmit channels by the transmitting entity, and wherein the selecting is further based on a probability that the transmitting would corrupt transmissions from another different transmitting entity.

15. The method of claim 1 further comprising updating the at least one attribute.

16. The method of claim 15 wherein the updating comprises measuring the at least one attribute.

17. The method of claim 1 wherein the receiving entity is a first receiving entity of at least two active receiving entities, each having the associated at least one attribute, the method further comprising prioritizing the at least two active receiving entities based on the at least one attribute.

18. The method of claim 17 wherein each of the at least two active receiving entities is sequentially assigned to a different one of the at least two transmit channels in an order determined by the prioritizing.

19. The method of claim 17 wherein each of the at least two active receiving entities is sequentially assigned to a different one of the at least two transmit channels in an order determined by the prioritizing, and wherein the at least two transmit channels are assigned in order of increasing back-off factor.

20. The method of claim 1 further comprising adjusting the back-off factor of at least one transmit channel of the at least two transmit channels.

21. The method of claim 20 wherein the adjusting is based on an estimated required transmit power level for the at least one transmit channel.

22. The method of claim 20 wherein the adjusting is based on a carrier-to-noise-plus-interference level for the at least one transmit channel.

23. The method of claim 20 wherein the adjusting is based on frame error rate for the at least one transmit channel.

24. The method of claim 20 wherein the adjusting is based on an outage probability for the at least one transmit channel.

25. The method of claim 20 wherein the adjusting comprises adjusting at least one back-off factor to zero.

26. An apparatus comprising a resource allocation processor configured to process a signal to be transmitted from a transmitting entity to a receiving entity by selecting a transmit channel from at least two transmit channels associated with the transmitting entity, wherein each of the at least two transmit channels has an associated back-off factor and transmit power, and wherein the transmit power for each of the at least two transmit channels is based on the back-off factor, and wherein the selecting is based on the back-off factor of the selected transmit channel and on at least one attribute associated with the receiving entity and assigning the selected transmit channel to the receiving entity.

27. An apparatus comprising:

means for selecting a transmit channel from at least two transmit channels associated with the transmitting entity, wherein each of the at least two transmit channels has an associated back-off factor and transmit power, and wherein the transmit power for each of the at least two transmit channels is based on the back-off factor for the transmit channel, and wherein the selecting is based on the back-off factor of the selected transmit channel and on at least one attribute associated with the receiving entity; and

means for assigning the selected transmit channel to the receiving entity.

28. A computer usable medium having computer readable program code embodying a method for processing a signal to be transmitted from a transmitting entity to a receiving entity, the method comprising:

selecting a transmit channel from at least two transmit channels associated with the transmitting entity, wherein each of the at least two transmit channels has an associated back-off factor and transmit power, and wherein the transmit power for each of the at least two transmit channels is based on the back-off factor for the transmit channel, and wherein the selecting is based on the back-off factor of the selected transmit channel and on at least one attribute associated with the receiving entity; and

assigning the selected transmit channel to the receiving entity.

29. A method for transmitting a downlink signal, the method comprising:

transmitting a first signal from a transmitting entity to a first receiving entity on a first time division multiplexed channel at a first transmit power level based on a first back-off factor; and

transmitting a second signal from the transmitting entity to a second receiving entity on a second time division multiplexed channel at a second transmit power level based on a second back-off factor, wherein the first transmit power level is different from the second transmit power level.

30. The method of claim 29 further comprising adjusting the first back-off factor.

31. The method of claim 30 wherein the adjusting is based on an estimated required transmit power level for the first signal.

32. The method of claim 30 wherein the adjusting is based on a carrier-to-noise-plus-interference level at which the first receiving entity receives the first signal on the first time domain multiplexed channel.

33. The method of claim 30 wherein the adjusting is based on frame error rate of the first signal as received through the first time domain multiplexed channel at the first receiving entity.

34. The method of claim 30 wherein the adjusting is based on an outage probability for the first time domain multiplexed channel.

35. The method of claim 30 wherein the adjusting comprises adjusting the first transmit power level to zero.

36. An apparatus comprising:

a resource allocation processor configured to provide a first back-off factor to a first transmitter and a second back-off factor to a second transmitter, wherein the first back-off factor is different from the second back-off factor; and

a transmitter configured to transmit a first signal on a first time division multiplexed channel at a first transmit power level based on the first back-off factor and to transmit a second signal on a second time division multiplexed channel at a second transmit power level based on the second back-off factor, wherein the first transmit power level is different from the second transmit power level.