Mechanisms for LAA/LTE-U detection to mitigate impact on Wi-Fi performance

• US 10,531,307 B2
• Filed: 02/13/2017
• Issued: 01/07/2020
• Est. Priority Date: 02/29/2016
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Belghoul, Farouk, Smaini, Lydi, Tabet, Tarik, Mujtaba, Syed Aon
• Primary Examiner(s): Scheibel, Robert C
• Application Number:
  US15/430,664
• Publication Number:
  US 20170251372A1
• Time in Patent Office: 1,058 Days
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

A wireless communication device may conduct first wireless communications over a first frequency band according to a first radio access technology (RAT), and may detect second wireless communications conducted over the first frequency band according to a second RAT while the wireless communication device is conducting the first wireless communications. The wireless communication device may then adjust characteristics and/or parameters associated with the first wireless communications based on the detected second wireless communications. In a specific example, a wireless communication device conducting Wi-Fi communications in the 5 GHz band may detect cellular communications (e.g. LAA/LTE-U communications) also conducted in the 5 GHz band while the wireless communication device is conducting the Wi Fi communications. The wireless communication device may then adjust characteristics and/or parameters associated with its Wi-Fi communications based on the detected signals/frequencies of the cellular (LAA/LTE-U) communications.

Claims

1. An apparatus comprising:

a memory element storing information; and

a processing element configured to use at least a portion of the information to cause a user equipment device (UE) to;

conduct first wireless communications in a first frequency band according to a first radio access technology (RAT), wherein the first wireless communications comprise Wi-Fi communications;

receive information from one or more other UEs during the first communications, wherein the information is associated with respective wireless communications conducted according to a second RAT by the one or more other UEs;

receive a signal in the first frequency band as part of the first communications, determine that the signal lacks an expected preamble associated with the first RAT, and detect that the signal is a synchronization signal associated with the second RAT partially in response to determining that the signal lacks the expected preamble;

determine, based at least on the received information and the detected synchronization signal, that there is a presence of second wireless communications conducted in the first frequency band according to the second RAT while the UE is conducting the first wireless communications, wherein the second wireless communications comprise cellular radio communications; and

adjust the first wireless communications at least in response to and based on the detected second wireless communications.

2. The apparatus of claim 1, wherein the first frequency band is an unlicensed frequency band for the second wireless communications.

3. The apparatus of claim 1, wherein the UE is operating as one of:

a peer-to-peer device;

an access point;

or

a station.

4. The apparatus of claim 1, wherein the processing element is configured to further cause the UE to detect an interfering second-RAT signal, wherein to detect the interfering second-RAT signal, the processing element is configured to cause the UE to:

bandpass filter, according to a first bandwidth, a signal received during the first wireless communications to produce a first filtered signal;

bandpass filter, according to a second bandwidth, the received signal to produce a second filtered signal; and

determine a presence of the interfering second-RAT signal based on the first filtered signal and the second filtered signal.

5. The apparatus of claim 1, wherein the processing element is configured to further cause the UE to detect interfering second-RAT signals by performing one or more of the following:

scanning the entire first frequency band;

scanning, in the frequency domain, a particular channel of the first frequency band;

or

passively receiving signals when operating in a specific channel of the first frequency band.

6. The apparatus of claim 5, wherein when scanning the entire first frequency band, the processing element is configured to cause the UE to obtain a power spectral density (PSD) for the first frequency band.

7. The apparatus of claim 6, wherein the processing element is configured to further cause the UE to:

perform a correlation of the obtained PSD with a specific second-RAT signal; and

detect an interfering second-RAT signal of the interfering second-RAT signals based on the correlation.

8. The apparatus of claim 6, wherein the processing element is configured to further cause the UE to obtain the PSD by performing a Fourier transform of an autocorrelation of a signal received during the first wireless communications.

9. The apparatus of claim 1, wherein the processing element is configured to cause the UE to detect that the signal is a synchronization signal associated with the second RAT by using time domain x-correlation between the signal and one or more possible complex-valued mathematical sequences.

10. The apparatus of claim 1, wherein the UE is preconfigured with a list of known frequencies and/or known channels over which the second wireless communications are conducted.

11. A user equipment device (UE) comprising:

first radio circuitry configured to facilitate wireless communications of the UE according to a first radio access technology (RAT);

second radio circuitry configured to facilitate wireless communications of the UE according to a second RAT; and

a processing element configured to interoperate with the first radio circuitry and the second radio circuitry to cause the UE to;

conduct first wireless communications in a first frequency band according to the first RAT;

receive information from one or more other UEs during the first communications, wherein the information is associated with respective wireless communications conducted according to a second RAT by the one or more other UEs;

receive a signal in the first frequency band as part of the first communications, determine that the signal lacks an expected preamble associated with the first RAT, and detect that the signal is a synchronization signal associated with the second RAT partially in response to determining that the signal lacks the expected preamble;

determine, based at least on the received information and the detected synchronization signal, that there is a presence of second wireless communications conducted in the first frequency band according to the second RAT while the UE is conducting the first wireless communications; and

adjust the first wireless communications at least in response to and based on the determined presence of the second wireless communications.

12. The UE of claim 11, wherein the processing element is configured to interoperate with the first radio circuitry and the second radio circuitry to further cause the UE to detect an interfering second-RAT signal, wherein to detect the interfering second-RAT signal, the processing element is configured to interoperate with the first radio circuitry and the second radio circuitry to cause the UE to:

bandpass filter, according to a first bandwidth, a signal received during the first wireless communications to produce a first filtered signal;

bandpass filter, according to a second bandwidth, the received signal to produce a second filtered signal; and

determine a presence of the interfering second-RAT signal based on the first filtered signal and the second filtered signal.

13. The UE of claim 11, wherein the processing element is configured to interoperate with the first radio circuitry and the second radio circuitry to further cause the wireless communication device to detect interfering second-RAT signals by performing one or more of the following:

scanning the entire first frequency band;

scanning, in the frequency domain, a particular channel of the first frequency band;

or

passively receiving signals when operating in a specific channel of the first frequency band.

14. The UE of claim 13, wherein the processing element is configured to interoperate with the first radio circuitry and the second radio circuitry to further cause the wireless communication device to:

when scanning the entire first frequency band, obtain a power spectral density (PSD) for the first frequency band;

perform a correlation of the obtained PSD with a specific second-RAT signal; and

detect an interfering second-RAT signal of the interfering second-RAT signals based on the correlation.

15. The UE of claim 11, wherein the processing element is configured to interoperate with the first radio circuitry and the second radio circuitry to further cause the UE to detect that the signal is a synchronization signal associated with the second RAT by using time domain x-correlation between the signal and one or more possible complex-valued mathematical sequences.

16. A non-transitory memory element storing instructions executable by a processing element to cause a user equipment device (UE) to:

conduct first wireless communications in a first frequency band according to a first radio access technology (RAT);

receive information from one or more other UEs during the first communications, wherein the information is associated with respective wireless communications conducted according to a second RAT by the one or more other UEs;

receive a signal in the first frequency band as part of the first communications, determine that the signal lacks an expected preamble associated with the first RAT, and detect that the signal is a synchronization signal associated with the second RAT partially in response to determining that the signal lacks the expected preamble;

determine, based at least on the received information and the detected synchronization signal, that there is a presence of second wireless communications conducted in the first frequency band according to the second RAT while the UE is conducting the first wireless communications; and

adjust the first wireless communications at least in response to and based on the determined presence of the second wireless communications.

17. The non-transitory memory element of claim 16, wherein the instructions are executable by the processing element to further cause the UE to detect an interfering second-RAT signal, wherein to detect the interfering second-RAT signal, the instructions are executable by the processing element to cause the UE to:

produce a first filtered signal by bandpass filtering, according to a first bandwidth, a received signal during the first wireless communications;

produce a second filtered signal by bandpass filtering, according to a second bandwidth, the received signal; and

determine a presence of the interfering second-RAT signal based on the first filtered signal and the second filtered signal.

18. The non-transitory memory element of claim 16, wherein the instructions are executable by the processing element to further cause the UE to:

to detect interfering second-RAT signals by performing one or more of the following;

scanning the entire first frequency band;

scanning, in the frequency domain, a particular channel of the first frequency band;

or

passively receiving signals when operating in a specific channel of the first frequency band.

19. The non-transitory memory element of claim 18, wherein the instructions are executable by the processing element to further cause the UE to:

when scanning the entire first frequency band, obtain a power spectral density (PSD) for the first frequency band;

perform a correlation of the obtained PSD with a specific second-RAT signal; and

detect an interfering second-RAT signal of the interfering second-RAT signals based on the correlation.

20. The non-transitory memory element of claim 16, wherein the instructions are executable by the processing element to cause the UE to detect that the signal is a synchronization signal associated with the second RAT by using time domain x-correlation between the signal and one or more possible complex-valued mathematical sequences.