Method and apparatus for physical layer radar pulse detection and estimation
View Patent ↗Radar Pulse detection and radar signal length detection are used to detect and provide information for identifying radar signals. Pulse detection estimates a radar pulse size when it is too short for meaningful measurement. Pulse detection identifies a radar by identification of an in-band pulse without a communication or data packet encoded therein, or a communication error is detected with the in-band pulse. Signal length detection counts the length of a received signal after the received signal exceeds a radar threshold. The count identifies the received signal length upon drop of the power. The signal is identified as a radar when the power drops before a PHY error occurs, or when the power drop occurs after a PHY error and a delay time equivalent to the shortest radar signal. A radar signal is also identified upon a timeout wait for a power drop after a PHY error.
1. A method of channel selection for wireless communications, comprising the steps of:
evaluating at least one channel for radar signals; and
performing the wireless communications on a selected channel that does not interfere with any detected radar signals;
wherein:
said step of evaluating comprises,
detecting a size increase of a received signal on the at least one channel,
determining if the received signal is a radar pulse, and
asserting a radar error if the received signal is a radar pulse; and
said step of determining if the received signal is a pulse comprises the steps of,
identifying the received signal as in-band pulse,
comparing a max pulse height of the received signal to a radar pulse height threshold, and
comparing a current signal strength to a threshold; and
the received signal is determined to be a radar pulse if it is in-band, has a pulse height greater than the radar pulse height threshold, and the current signal strength is significantly less than a signal strength threshold.
2. The method according to claim 1 , wherein said wireless communications are wireless LAN communications.
3. The method according to claim 1 , wherein said wireless communications are IEEE 802.11 a based communications.
4. The method according to claim 1 , wherein said radar signals are a predetermined set of radar signals.
5. The method according to claim 1 , wherein said radar signals are a predetermined set of radar signals identified by at least one of radar pulse width, height, and repetition frequency.
6. The method according to claim 1 , wherein said radar signals are a predetermined set of radar signals identified by the European Telecommunications Standards Institute (ETSI).
7. The method according to claim 1 , wherein said step of evaluating comprises evaluating the selected channel and at least one neighboring channel.
8. The method according to claim 1 , further comprising the steps of:
monitoring the selected channel for new radar signals listening on at least the selected channel.
9. The method according to claim 1 , wherein:
said method is embodied in a set of computer instructions stored on a computer readable media;
said computer instructions, when loaded into a computer, cause the computer to perform the steps of said method.
10. The method according to claim 9 , wherein said computer instruction are compiled computer instructions stored as an executable program on said computer readable media.
11. The method according to claim 1 , wherein said method is embodied in a set of computer readable instructions stored in an electronic signal.
12. A method of channel selection for wireless communications, comprising the steps of:
evaluating at least one channel for radar signals; and
performing the wireless communications on a selected channel that does not interfere with any detected radar signals;
wherein:
said step of evaluating comprises,
detecting a size increase of a received signal on the at least one channel,
determining if the received signal is a radar pulse, and
asserting a radar error if the received signal is a radar pulse; and
said step of determining if the received signal is a pulse comprises the steps of,
identifying the received signal as in-band pulse,
comparing a max pulse height of the received signal to a radar pulse height threshold, and
comparing a current signal strength to a threshold; and
the received signal is determined to be a radar pulse if it is in-band, has a pulse height greater than the radar pulse height threshold, and the current signal strength is significantly less than a signal strength threshold, and
said radar signals are evaluated as belonging to a predetermined set of radar signals.
13. The method according to claim 12 , wherein the predetermined set of radar signals are identified by a government regulatory agency as signals to be avoided in order for a device to be approved for use by the regulatory agency.
14. The method according to claim 13 , wherein the government regulatory agency is the European Telecommunicalions Standards Institute (ETSI).
15. The method according to claim 12 , wherein the predetermined set of radar signals comprises at least one of the radar signals identified in Table 1.
16. The method according to claim 12 , wherein the predetermined set of radar signals comprises all of the radar signals identified in Table 1.
17. A method of channel selection for wireless communications, comprising the steps of:
evaluating at least one channel for radar signals by determining if a signal received on the at least one channel is an in-band radar signal belonging to a predetermined set of radars; and
performing the wireless communications on a selected channel that does not interfere with any detected radar signals;
wherein:
said step of evaluating comprises,
detecting a size increase of a received signal on the at least one channel,
determining if the received signal is a radar pulse, and
asserting a radar error if the received signal is a radar pulse; and
said step of determining if the received signal is a pulse comprises the steps of,
identifying the received signal as in-band pulse,
comparing a max pulse height of the received signal to a radar pulse height threshold, and
comparing a current signal strength to a threshold; and
the received signal is determined to be a radar pulse if it is in-band, has a pulse height greater than the radar pulse height threshold, and the current signal strength is significantly less than a signal strength threshold.
18. The method according to claim 17 , wherein the predetermined set of radars comprises a set of radar signals identified by a governmental regulatory agency.
19. The method according to claim 17 , wherein the predetermined set of radars comprises a set of radar signals identified by the European Telecommunications Standards Institute (ETSI).
20. A method of channel selection for wireless communications, comprising the steps of:
evaluating at least one channel for radar signals, comprising,
detecting a size increase of a received signal on the at least one channel,
determining if the received signal is a radar pulse, and
asserting a radar error if the received signal is a radar pulse; and
performing the wireless communications on a selected channel that does not interfere with any detected radar signals;
wherein:
said step of determining if the received signal is a pulse comprises the steps of,
identifying the received signal as in-band pulse,
comparing a max pulse height of the received signal to a radar pulse height threshold, and
comparing a current signal strength to a threshold; and
the received signal is determined to be a radar pulse if it is in-band, has a pulse height greater than the radar pulse height threshold, and the current signal strength is significantly less than a signal strength threshold.
21. The method according to claim 20 , wherein the communication signals are IEEE 802.11 based signals.
22. The method according to claim 20 , wherein the determined radar pulses comprise radar signals identified by the European Telecommunications Standards Institute (ETSI).