Wi-Fi adaptive transmit antenna selection

• US 10,014,900 B2
• Filed: 09/18/2017
• Issued: 07/03/2018
• Est. Priority Date: 11/03/2014
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Wang, Xiaowen, Mujtaba, Syed Aon, Majjigi, Vinay R., Kim, Joonsuk
• Primary Examiner(s): Hanidu, Ganiyu A
• Application Number:
  US15/707,246
• Publication Number:
  US 20180006677A1
• Time in Patent Office: 288 Days
• Field of Search: 455 6711, 455138, 455 83, 375260, 375347
• CPC Class Codes: H04B 1/40 Circuits
• CPC Class Codes: H04B 7/061 using feedback from receiving side
• CPC Class Codes: H04B 7/0817 with multiple receivers and antenna path selection
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 88/08 Access point devices
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Wireless communication devices (UEs) may include multiple receive (RX) chains and associated antennas, and at least one transmit (TX) chain co-located with one of the RX chains. The UE may track instant fading of the antenna gain(s) during reception of packets from an associated access point (AP) device to which the UE intends to transmit packets. The UE may also track long term antenna gain(s), using any packets received at the multiple RX chains within the UE. At a switching occasion, a decision is made by the UE whether to switch antennas. If the instant fading detection is based on packets received no later than a specified time period prior to the switching occasion, then the UE may make the switching decision based on the results of the instant fading tracking. Otherwise, the UE may make the switching decision based on the results of the long term antenna gain tracking.

Claims

1. A wireless communication device comprising:

a first antenna and a second antenna, configured to transmit and receive signals;

a first receive chain and a second receive chain, communicatively coupled to the first antenna and the second antenna for receiving packets;

a transmit chain communicatively coupled to the first antenna and the second antenna for transmitting packets; and

a processing element configured to;

track a respective performance measure of the first antenna and the second antenna during operation of the first receive chain and the second receive chain; and

select, at a switching occasion, one of the first antenna or the second antenna for transmitting packets via the transmit chain, based at least in part on the tracked respective performance measure of the first antenna and the second antenna.

2. The wireless communication device of claim 1, wherein the processing element tracking the respective performance measure of the first antenna and the second antenna comprises:

tracking an instant change in respective gain performance of the first antenna and the second antenna; and

tracking respective long-term gains of the first antenna and the second antenna.

3. The wireless communication device of claim 1, wherein, the processing element selecting, at the switching occasion, one of the first antenna or the second antenna for transmitting packets via the transmit chain is further based on when a most recent packet used for tracking a specified performance characteristic corresponding to the respective performance measure is received prior to the switching occasion.

4. The wireless communication device of claim 1, wherein the processing element selecting, at the switching occasion, one of the first antenna or the second antenna for transmitting packets via the transmit chain is based on one of:

a first performance characteristic corresponding to the respective performance measure, when a most recent packet used for tracking the first performance characteristic is received no later than a specified point in time prior to the switching occasion;

or

a second performance characteristic corresponding to the respective performance measure, when the most recent packet is received later than the specified point in time prior to the switching occasion.

5. The wireless communication device of claim 1, wherein the respective performance measure corresponds to tracked instant changes in respective gain performance of the first antenna and the second antenna, and comprises:

a threshold obtained from a sum of a prediction error margin; and

a gain difference between the first antenna and the second antenna.

6. The wireless communication device of claim 1, wherein the respective performance measure corresponds to tracked respective long-term gains of the first antenna and the second antenna, and comprises a threshold obtained from a sum of:

a difference in average gain between the first antenna and the second antenna; and

a threshold difference adapted to a sample interval between reception of subsequent receive packets.

7. The wireless communication device of claim 1, wherein the processing element tracking the respective performance measure of the first antenna and the second antenna comprises:

tracking an instant change in respective gain performance of the first antenna and the second antenna for one or more packets received from an access point communicating with the wireless communication device.

8. An apparatus comprising:

a processing element configured to;

track, in a wireless communication device, a respective performance measure of a first antenna and a second antenna during operation of a first receive chain and a second receive chain each comprised in the wireless communication device, the first receive chain and the second receive chain communicatively coupled to the first antenna and the second antenna for receiving packets, wherein a transmit chain comprised in the wireless communication device is communicatively coupled to the first antenna and the second antenna for transmitting packets; and

select, at a switching occasion, one of the first antenna or the second antenna for transmitting packets via the transmit chain, based at least in part on the tracked respective performance measure of the first antenna and the second antenna.

9. The apparatus of claim 8, wherein the processing element tracking the respective performance measure of the first antenna and the second antenna comprises:

tracking an instant change in respective gain performance of the first antenna and the second antenna; and

tracking respective long term gains of the first antenna and the second antenna.

10. The apparatus of claim 8, wherein the processing element selecting, at the switching occasion, one of the first antenna or the second antenna for transmitting packets via the transmit chain is further based on when a most recent packet used for tracking a specified performance characteristic corresponding to the respective performance measure is received prior to the switching occasion.

11. The apparatus of claim 8, wherein the processing element selecting, at the switching occasion, one of the first antenna or the second antenna for transmitting packets via the transmit chain is based on one of:

a first performance characteristic corresponding to the respective performance measure, when a most recent packet used for tracking the first performance characteristic is received no later than a specified point in time prior to the switching occasion;

or

a second performance characteristic corresponding to the respective performance measure, when the most recent packet is received later than the specified point in time prior to the switching occasion.

12. The apparatus of claim 8, wherein the respective performance measure corresponds to tracked instant changes in respective gain performance of the first antenna and the second antenna, and comprises:

a threshold obtained from a sum of a prediction error margin; and

a gain difference between the first antenna and the second antenna.

13. The apparatus of claim 8, wherein the respective performance measure corresponds to tracked respective long-term gains of the first antenna and the second antenna, and comprises a threshold obtained from a sum of:

a difference in average gain between the first antenna and the second antenna; and

a threshold difference adapted to a sample interval between reception of subsequent receive packets.

14. The apparatus of claim 8, wherein the processing element tracking the respective performance measure of the first antenna and the second antenna comprises:

tracking an instant change in respective gain performance of the first antenna and the second antenna for one or more packets received from an access point device communicating with the wireless communication device.

15. A non-volatile memory device storing instructions executable by a processing element to cause processor electronics to:

track a respective performance measure of a first antenna and a second antenna of a wireless communication device during operation of a first receive chain and a second receive chain of the wireless communication device, the first receive chain and the second receive chain communicatively coupled to the first antenna and the second antenna for receiving packets, wherein a transmit chain is communicatively coupled to the first antenna and the second antenna for transmitting packets; and

select, at a switching occasion, one of the first antenna or the second antenna for transmitting packets via the transmit chain, based at least in part on the tracked the respective performance measure of the first antenna and the second antenna.

16. The non-volatile memory device of claim 15, wherein the processor electronics tracking the respective performance measure of the first antenna and the second antenna comprises:

tracking an instant change in respective gain performance of the first antenna and the second antenna; and

tracking respective long term gains of the first antenna and the second antenna.

17. The non-volatile memory device of claim 15, wherein the instructions are executable by the processing element to further cause the processor electronics to select, at the switching occasion, one of the first antenna or the second antenna for transmitting packets via the transmit chain, based on:

when a most recent packet used for tracking a specified performance characteristic corresponding to the respective performance measure is received prior to the switching occasion.

18. The non-volatile memory device of claim 15, wherein the instructions are executable by the processing element to further cause the processor electronics to select, at the switching occasion, one of the first antenna or the second antenna for transmitting packets via the transmit chain, based on one of:

a first performance characteristic corresponding to the respective performance measure, when a most recent packet used for tracking the first performance characteristic is received no later than a specified point in time prior to the switching occasion;

or

a second performance characteristic corresponding to the respective performance measure, when the most recent packet is received later than the specified point in time prior to the switching occasion.

19. The non-volatile memory device of claim 18;

wherein the first performance characteristic is indicative of instant changes in respective gain performance of the first antenna and the second antenna, and comprises;

a threshold obtained from a sum of a prediction error margin; and

a gain difference between the first antenna and the second antenna; and

wherein the second performance characteristic is indicative of respective long-term gains of the first antenna and the second antenna, and comprises a threshold obtained from a sum of;

a difference in average gain between the first antenna and the second antenna; and

a threshold difference adapted to a sample interval between reception of subsequent receive packets.

20. The non-volatile memory device of claim 15, wherein the processor electronics tracking the respective performance measure of the first antenna and the second antenna comprises:

the processor electronics tracking an instant change in respective gain performance of the first antenna and the second antenna for one or more packets received from an access point.