Method for calibrating and AOA location system for frequency hopping air interfaces

A method of calibrating an antenna array and signal processing system for receiving a frequency hopping communication signal comprising the steps of:

• obtaining a frequency hopping sequence of the communication signal
• injecting a calibration signal at one frequency of the frequency hopping sequence of the communication signal in response to receipt of said communication signal;
• determining a calibration coefficient C1 for said one frequency;
• storing said calibration coefficient C1,
• receiving the communication signal;
• and,
• applying the calibration coefficient C1 to the communication signal for each frequency of the communication signal.

In a network overlay geolocation system, a method for locating a mobile appliance including determining the AOA of an uplink signal from the mobile appliance at a base station from measurements, by a wireless location sensor, of an attribute of the uplink signal and a frequency specific calibration of a path between a multi element antenna array and the wireless location sensor, the improvement comprising the steps of:

• (a) collecting segments of a frequency hopping signal associated with a specific hop;
• (b) calibrating the path, at approximately the specific hop's frequency, proximate in time to the collecting of the segment, over a plurality of hopping sequence cycles;
• and,
• (c) estimating the AOA of a frequency hopping signal from the collected segments associated with the specific hop and the path calibrations at approximately the specific hop's frequency.