Wireless devices and systems including examples of cross correlating wireless transmissions

A method, comprising:

• receiving, from a first antenna and a second antenna of a plurality of antennas, respective radio frequency (RF) energies;
• cross-correlating symbols indicative of RF energy associated with the first antenna, the symbols indicative of the RF energy comprising a first signal, with a pilot signal that is different from the first signal to calculate a first cross-correlation statistic;
• cross-correlating symbols indicative of RF energy associated with the first antenna with symbols indicative of RF energy associated with the second antenna to calculate a second cross-correlation statistic, wherein cross-correlating symbols indicative of RF energy associated with the first antenna with symbols indicative of RF energy associated with the second antenna comprises:
• combining the RF energies received at each of the first and second antennas of the plurality of antennas;
• calculating a symbol duration based on a time period in which a symbol of the symbols indicative of RF energy associated with the first antenna is received;
• and
• calculating the cross-correlation statistic based on the combined RF energies and the symbol duration;
• comparing, at a pilot statistic calculator, the first statistic to a first threshold that at least partially indicates whether a wireless communications signal including encoded data is present;
• comparing, at a statistic calculator, the second statistic to a second threshold that indicates whether a wireless communications signal including encoded data is present;
• and
• based on the wireless communications signal being present, providing a signal indicative of the wireless communications signal including the encoded data to a decoder.

An apparatus comprising:

• a plurality of antennas;
• a first transceiver configured to receive a first radio frequency (RF) signal from a first antenna of the plurality of antennas;
• a second transceiver configured to receive a second radio frequency (RF) signal from a second antenna of the plurality of antennas;
• a first communication detector coupled to the first transceiver and the second transceiver, the first communication detector comprising:
• a pilot signal statistic calculator configured to calculate a first cross-correlation statistic of symbols indicative of the first RF signal comprising a first signal, or the symbols indicative of the second RF signal comprising a second signal, with a pilot signal different from the first signal and the second signal;
• a statistic calculator configured to calculate a symbol duration based on a time period in which a symbol of the symbols indicative of the first RF signal is received from the first antenna of the plurality of antennas, and wherein the statistic calculator is further configured to cross-correlate symbols indicative of the first RF signal and symbols indicative of the second RF signal using the symbol duration to calculate a second cross-correlation statistic;
• a first comparator coupled to the pilot statistic calculator configured to provide a third signal that at least partially indicates whether a wireless communications signal including encoded data is present in the first RF signal or the second RF signal based, at least in part, on a comparison of the first cross-correlation statistic with a first threshold;
• and
• a second comparator coupled to the statistic calculator and configured to provide a fourth signal that indicates whether a wireless communications signal including encoded data is present in the first RF signal or the second RF signal based, at least in part, on a comparison of the second cross-correlation statistic with a second threshold.