Power-Aware Coexistence

• US 20130344821A1
• Filed: 06/20/2012
• Published: 12/26/2013
• Est. Priority Date: 06/20/2012
• Status: Active Grant

• Current Assignee: Qualcomm technologies international, ltd. (Qualcomm, Inc.)
• Original Assignee: Cambridge Silicon Radio Limited (Qualcomm, Inc.)
• Inventors: Armstrong, Dean, Grocutt, Thomas Christopher
• Granted Patent: US 9,723,620 B2
• Time in Patent Office: Days
• US Class Current: 455/79
• CPC Class Codes: H04W 72/1215 for collaboration of different radio technologies
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A communication device comprising: a receiver operable to receive radio transmissions according to a first communication protocol; a transmitter operable to transmit radio transmissions according to a second communication protocol; and an arbiter connected to the receiver and transmitter; wherein the arbiter is configured to: receive from the transmitter an indication of a first transmit operation intended for performance during a first time period and one or more intended transmit characteristics of the first transmit operation, including a representation of the intended transmit power; determine whether the receiver intends to perform a communication operation during the first time period; determine in dependence on the transmit characteristics and the receive quality, a set of one or more threshold transmit characteristics for the first transmit operation; and cause the transmitter to proceed with the first transmit operation only if its transmit characteristics are constrained in accordance with the threshold transmit characteristics.

Claims

1. A communication device comprising:

a receiver operable to receive radio transmissions according to a first communication protocol;

a transmitter operable to transmit radio transmissions according to a second communication protocol; and

an arbiter connected to the receiver and transmitter;

wherein radio transmissions from the transmitter are capable of interfering with the reception of radio transmissions by the receiver, and the arbiter is configured to;

receive from the transmitter an indication of a first transmit operation intended for performance during a first time period and one or more intended transmit characteristics of the first transmit operation, including a representation of the intended transmit power;

determine whether the receiver intends to perform a communication operation during the first time period;

if the receiver intends to perform a first receive operation having one or more intended receive characteristics during the first time period, accessing an indication of receive quality determined by the receiver;

determine in dependence on the transmit characteristics and the receive quality, a set of one or more threshold transmit characteristics for the first transmit operation, the threshold transmit characteristics including a representation of a maximum transmit power at which the transmitter is permitted to perform the first transmit operation; and

cause the transmitter to proceed with the first transmit operation only if its transmit characteristics are constrained in accordance with the threshold transmit characteristics.

2. A communication device as claimed in claim 1, wherein the intended transmit characteristics include an indication of one or more of the channel, frequency range, modulation scheme, and selection of one or more first antennas intended for the first transmit operation.

3. A communication device as claimed in claim 1, wherein the indication of receive quality is one or more of received signal strength, received power, a measure of noise level, a measure of error rate, and a number of packets dropped.

4. A communication device as claimed in claim 1, wherein the indication of receive quality represents a measure of the receive quality of one or more previous reception operations.

5. A communication device as claimed in claim 4, wherein the receive quality is an average of a predetermined number of previous reception operations.

6. A communication device as claimed in claim 4, wherein the one or more previous reception operations are reception operations performed over one or more of the same channel, frequency range, modulation scheme, and selection of one or more second antennas as intended for the first receive operation.

7. A communication device as claimed in claim 1, wherein the first time period includes a single data packet, a burst of data packets, or a predetermined length of time.

8. A communication device as claimed in claim 1, wherein the receiver is configured to notify the arbiter of the first receive operation by writing a receive indicator to a memory along with an indication of receive quality at the receiver, the arbiter being configured to access the memory in order to determine whether the receiver intends to perform a receive operation during the first time period and to receive from the receiver an indication of receive quality at the receiver.

9. A communication device as claimed in claim 1, wherein the receiver is configured to notify the arbiter of the first receive operation by sending a receive indicator to the arbiter, the receive indicator comprising an indication of receive quality at the receiver.

10. A communication device as claimed in claim 8 or 9, wherein the receive indicator includes the intended receive characteristics of the first receive operation.

11. A communication device as claimed in claim 1, wherein the intended transmit characteristics comprise an indication of the intended transmit channel and the intended receive characteristics comprise an indication of the intended receive channel, and the arbiter is configured to determine the threshold transmit characteristics in dependence on the intended transmit and/or receive channels.

12. A communication device as claimed in claim 11, wherein the arbiter is configured to determine the threshold transmit characteristics in dependence on a measure of the relative or absolute separation of the intended receive and transmit channel frequencies.

13. A communication device as claimed in claim 1, wherein the arbiter is configured to determine the threshold transmit characteristics in dependence on threshold data held at a data store.

14. A communication device as claimed in claim 13, wherein the arbiter is configured to dynamically update the threshold data in dependence on the receive quality of receive operations performed by the receiver.

15. A communication device as claimed in claim 13, wherein at least some of the threshold data is determined from empirical measurements or computational modeling of receive quality at the receiver for transmit operations performed by the transmitter having a range of transmit characteristics.

16. A communication device as claimed in claim 13, wherein the threshold data includes one or more threshold algorithms and the arbiter is configured to determine the threshold transmit characteristics by performing the threshold algorithms.

17. A communication device as claimed in claim 16, wherein the threshold algorithms include one or more mathematical equations describing the variation of receive quality with transmit power and optionally frequency.

18. A communication device as claimed in claim 1, wherein the transmitter is configured to send the indication of a first transmit operation to the arbiter as a transmit request comprising the intended transmit characteristics.

19. A communication device as claimed in claim 18, wherein the arbiter is configured to infer the first time period from the timing of the transmit request.

20. A communication device as claimed in claim 18, wherein the transmit request comprises information identifying the first time period.

21. A communication device as claimed in claim 18, wherein the arbiter is configured to cause the transmitter to proceed with the first transmit operation by sending to the transmitter a transmit response comprising the threshold transmit characteristics.

22. A communication device as claimed in claim 1, wherein the transmitter is further configured to receive an indication of the link margin at a remote receiver to which the transmitter has established a communication link over which the first transmit operation is to be transmitted.

23. A communication device as claimed in claim 22, wherein the link margin is representative of the reception quality of previous transmit operations by the transmitter over the communication link.

24. A communication device as claimed in claim 22, wherein the transmitter is configured to determine whether to perform the first transmit operation in dependence on the threshold transmit characteristics and the link margin.

25. A communication device as claimed in claim 22, wherein the transmitter is configured to not perform the first transmit operation if the link margin is below a predetermined level and the maximum transmit power at which the transmitter is permitted to perform the first transmit operation is lower than the intended transmit power.

26. A communication device as claimed in claim 22, wherein the transmitter is configured to include the indication of the link margin in the intended transmit characteristics and the arbiter is configured to determine whether to perform the first transmit operation by:

estimating the link margin at the remote receiver if the first transmit operation were performed in accordance with the threshold transmit characteristics; and

causing the transmitter to not perform the first transmit operation if the estimated link margin is below a predetermined level.

27. A communication device as claimed in claim 1, wherein the transmitter is operable to transmit by means of two or more antennas and the threshold transmit characteristics include an indication of one or more of:

the maximum transmit power permitted from each of the antennas;

an indication of which of the antennas are permitted to be used;

an indication of a beam direction; and

a modulation scheme in accordance with which the first transmit operation is to be performed.

28. A communication device as claimed in claim 1, wherein the receiver is a transceiver and if, on determining whether the receiver intends to perform any communication operations during the first time period, the arbiter determines that the transceiver intends to transmit during the first time period, the arbiter is configured to cause the transmitter to not perform the first transmit operation.

29. A communication device as claimed in claim 1, wherein the communication device comprises first and second radio transceivers either of which are operable as the recited transmitter.

30. A communication device as claimed in claim 1, wherein the transmitter and receiver are provided at a common integrated circuit die.

31. A communication device as claimed in claim 30, wherein the arbiter is provided at the common integrated circuit die.

32. A communication device as claimed in claim 1, wherein the arbiter operates at the physical layer.

33. A communication device as claimed in claim 1, wherein the arbiter comprises software executing at a processor of the communication device and operates at the data link layer.

34. A communication device as claimed in claim 1, wherein the first and/or second communication protocols are Bluetooth or an IEEE 802.11 protocol.

35. A method for managing radio transmissions from a transmitter capable of causing interference at a collocated radio receiver, the transmitter and receiver being connected to an arbiter and the method comprising:

the transmitter indicating to the arbiter a first transmit operation intended for performance during a first time period and making available to the arbiter one or more intended transmit characteristics of the first transmit operation, including a representation of the intended transmit power;

the arbiter;

determining whether the receiver intends to perform a communication operation during the first time period;

if the receiver intends to perform a first receive operation having one or more intended receive characteristics during the first time period, accessing an indication of receive quality determined by the receiver;

determining in dependence on the transmit characteristics and the receive quality, a set of one or more threshold transmit characteristics for the first transmit operation, the threshold transmit characteristics including a representation of a maximum transmit power at which the transmitter is permitted to perform the first transmit operation; and

causing the transmitter to proceed with the first transmit operation only if its transmit characteristics are constrained in accordance with the threshold transmit characteristics.

36. An integrated circuit comprising:

a receiver for receiving according to a first radio communication protocol;

a transmitter for transmitting according to a second radio communication protocol; and

an arbiter connected to the receiver and transmitter;

wherein radio communications according to the first radio communication protocol are capable of interfering with communications according to the second radio communication protocol, and the arbiter is configured to;

receive from the transmitter an indication of a first transmit operation intended for performance during a first time period and one or more intended transmit characteristics of the first transmit operation, including a representation of the intended transmit power;

determine whether the receiver intends to perform a communication operation during the first time period;

if the receiver intends to perform a first receive operation having one or more intended receive characteristics during the first time period, accessing an indication of receive quality determined by the receiver;

determine in dependence on the transmit characteristics and the receive quality, a set of one or more threshold transmit characteristics for the first transmit operation, the threshold transmit characteristics including a representation of a maximum transmit power at which the transmitter is permitted to perform the first transmit operation; and

cause the transmitter to proceed with the first transmit operation only if its transmit characteristics are constrained in accordance with the threshold transmit characteristics.