Dynamic Antenna Switching

• US 20150349870A1
• Filed: 05/30/2014
• Published: 12/03/2015
• Est. Priority Date: 05/30/2014
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Agboh, Peter M., Liu, Hsin-Yuo, Hernandez, Diego C., Jadhav, Digvijay A., Caballero, Ruben, Chen, Xiaojun, Sen, Indranil S., Reddy, Vusthia Sunil, Narang, Mohit
• Granted Patent: US 9,231,686 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04B 7/0817 with multiple receivers and antenna path selection
• CPC Class Codes: H04B 7/0822 according to predefined selection scheme

Abstract

Dynamic antenna switching based on weighted signal to noise ratio (SNR). A wireless device may include multiple antennas. SNR at each active antenna may be calculated. An antenna-specific weight may be applied to each antenna'"'"'s SNR. The antenna-specific weights may further be radio specific and/or transmit or receive specific in some cases. Antenna selection (possibly just for a specific radio and/or for transmit or receive operations, depending on the specificity of the antenna weights), including potentially switching which antenna is used, may be based on the resulting weighted SNR values for each antenna. If the antenna-specific weights are radio specific and/or transmit or receive operation specific, the method may be performed multiple times with different antenna-specific weights to select antenna(s) for different radios and/or for other operations.

Claims

1. A wireless user equipment (UE) device, comprising:

a plurality of antennas;

a plurality of radios; and

antenna switching logic coupled to the plurality of radios and the plurality of antennas;

wherein the antenna switching logic is configured to;

calculate signal-to-noise ratio (SNR) of receive frames on each active antenna of the plurality of antennas; and

for each respective radio of the plurality of radios;

calculate a receive-weighted SNR for each active antenna using a respective receive-specific set of antenna weights; and

select one or more antennas for use by the respective radio for reception based on the receive-weighted SNR for each active antenna.

2. The UE of claim 1, wherein the antenna switching logic is further configured to, for each respective radio of the plurality of radios:

calculate a transmit-weighted SNR for each active antenna using a respective transmit-specific set of antenna weights;

select one or more antennas for use by the respective radio for transmission based on the transmit-weighted SNR for each active antenna.

3. The UE of claim 2,

wherein at least one antenna weight differs between a respective transmit-specific set of antenna weights and a respective receive-specific set of antenna weights for at least one radio.

4. The UE of claim 1, wherein selecting the one or more antennas for use by a respective radio for reception is based at least in part on a delta between weighted SNR of an antenna having a highest receive-weighted SNR and weighted SNR of an antenna currently used for reception by the respective radio.

5. The UE of claim 1, wherein to select the one or more antennas for use by a respective radio for reception, the antenna switching logic is further configured to:

calculate a weighted SNR delta between an antenna having a highest receive-weighted SNR and an antenna currently used for reception by the respective radio; and

select the antenna having the highest receive-weighted SNR for use by the respective radio for reception if the weighted SNR delta is greater than a SNR threshold;

select the antenna currently used for reception by the respective radio for use by the respective radio for reception if the weighted SNR delta is less than the SNR threshold and a timer has not expired;

or

select an inactive antenna for use by the respective radio for reception if the weighted SNR delta is less than the SNR threshold and the timer has expired.

6. The UE of claim 1, wherein a respective receive-specific set of antenna weights of a respective radio is configured based on one or more of:

antenna characteristics;

radio characteristics;

characteristics of a wireless communication technology according to which the respective radio operates; and

co-existence considerations between wireless communication technologies currently active in the UE.

7. The UE of claim 1,

wherein calculating SNR of receive frames comprises updating a moving average SNR over a plurality of recently received frames.

8. A method for a wireless user equipment (UE) device, comprising:

calculating a weighted signal-to-noise ratio (SNR) of each antenna of a plurality of antennas of a wireless device, wherein calculating the weighted SNR of each antenna comprises applying an antenna-specific weight factor to SNR of frames received on the antenna;

selecting an antenna from the plurality of antennas based on the weighted SNR of each of the plurality of antennas,

performing wireless communication using the selected antenna.

9. The method of claim 8,

wherein said calculating, selecting, and performing are performed for each of a plurality of radios of the UE, wherein calculating the weighted SNR of each antenna uses different antenna-specific weight factors for each of the plurality of radios.

10. The method of claim 8,

wherein said calculating, selecting, and performing are performed for each of transmit and receive operations of the UE, wherein calculating the weighted SNR of each antenna uses different antenna-specific weight factors for transmit and receive operations.

12. The method of claim 8, wherein selecting the antenna comprises:

calculating a difference between a highest weighted SNR of the plurality of antennas and a weighted SNR of an antenna most recently used for wireless communication; and

selecting an antenna having the highest weighted SNR if the difference between the highest weighted SNR and the weighted SNR of the antenna most recently used for wireless communication is greater than a weighted SNR threshold.

13. The method of claim 12, wherein selecting the antenna further comprises:

selecting the antenna most recently used for wireless communication if the difference between the highest weighted SNR and the weighted SNR of the antenna most recently used for wireless communication is less than the weighted SNR threshold and if a timer has not expired.

14. The method of claim 13, wherein selecting the antenna further comprises:

selecting a currently inactive antenna if the difference between the highest weighted SNR and the weighted SNR of the antenna most recently used for wireless communication is less than the weighted SNR threshold and if the timer has expired.

15. The method of claim 8,

wherein the selected antenna has a highest weighted SNR of the plurality of antennas.

16. The method of claim 8, the method further comprising:

repeating said calculating, selecting, and performing a plurality of times in a periodic manner.

11. (canceled)

17. A non-transitory computer-accessible memory medium comprising program instructions which, when executed by a wireless user equipment (UE) device, cause the UE to:

initially receive wireless communication signals at a first radio of the UE via a first antenna of the UE;

calculate weighted signal-to-noise ratio (SNR) of each of the first antenna and a second antenna of the UE;

select the second antenna of the UE for subsequent wireless reception by the first radio based at least in part on calculating the weighted SNR of each of the first antenna and the second antenna of the UE; and

switch an antenna used to receive wireless communication signals at the first radio from the first antenna to the second antenna based on selecting the second antenna of the UE for subsequent wireless reception by the first radio.

18. The memory medium of claim 17,

wherein calculating the weighted SNR of each of the first antenna and the second antenna comprises applying a first antenna weight to a SNR of the first antenna and a second antenna weight to a SNR of the second antenna.

19. The memory medium of claim 18,

wherein the first antenna weight and the second antenna weight are different and are based on one or more of:

a type of wireless communication performed by the first radio;

antenna imbalance of each of the first antenna and the second antenna; and

types of wireless communication being performed by other components of the UE.

20. The memory medium of claim 17,

wherein the second antenna is selected based on having a weighted SNR greater than the weighted SNR of the first antenna by at least a weighted SNR threshold.