Estimating and using characteristic differences between wireless signals

A method of identifying that a first wireless signal and a second wireless signal were transmitted from the same location, the method comprising:

• receiving, at a first location, a first wireless signal and a second wireless signal, thereby producing first received signals;
• receiving, at a second location, the first wireless signal and the second wireless signal, thereby producing second received signals;
• processing the first received signals to estimate one or more first characteristic differences between them;
• processing the second received signals to estimate one or more second characteristic differences between them;
• comparing the one or more first characteristic differences with the one or more second characteristic differences to determine whether they match;
• and
• in response to a determination that the one or more first characteristic differences match with the one or more second characteristic differences, determining that the first and second wireless signals were transmitted from the same location,
• wherein the first wireless signal is transmitted in a first frequency range and the second wireless signal is transmitted in a second frequency range, spaced from the first frequency range, and
• wherein at least one of the one or more first characteristic differences or the one or more second characteristic differences comprise at least one or any combination of two or more of:
• a time offset;
• a carrier phase relationship;
• and
• an amplitude relationship,
• wherein at least one of processing the first received signals or processing the second received signals further comprises:
• estimating a combined time of arrival for the first wireless signal and the second wireless signal, wherein estimating the combined time of arrival is based on the first wireless signal, the second wireless signal, the one or more first characteristic differences, or the one or more second characteristic differences, and wherein estimating the combined time of arrival comprises:
• aligning a first channel impulse response and a second channel impulse response, based on the one or more first characteristic differences or the one or more second characteristic differences, to generate aligned channel impulse responses;
• combining the aligned channel impulse responses to generate a combined channel impulse response;
• and
• estimating the combined time of arrival from the combined channel impulse response.

A method of maintaining a database of characteristic difference information associated with groups of signals, each group of signals being transmitted from a respective location, at least one group of signals including a first wireless signal transmitted in a first frequency range and a second wireless signal transmitted in a second frequency range spaced from the first frequency range, the method comprising:

• obtaining one or more characteristic differences between signals in each group, wherein the one or more characteristic differences comprise at least one or any combination of two or more of:
• a time offset,
• a carrier phase relationship, and
• an amplitude relationship,
• obtaining identity information identifying each group of signals;
• and
• storing the one or more characteristic differences in the database, associated with the identity information,
• the method further comprising:
• receiving a request for characteristic difference information associated with a target group of signals, the request including target identity information identifying the target group of signals;
• searching the database using the target identity information;
• and
• retrieving from the database the one or more characteristic differences for the target group of signals,
• wherein obtaining the one or more characteristic differences between the signals in each group comprises:
• estimating a combined time of arrival for the signals, wherein estimating the combined time of arrival is based on the signals and the one or more characteristic differences, and wherein estimating the combined time of arrival comprises:
• aligning each of channel impulse responses associated with the signals, based on the one or more characteristic differences, to generate aligned channel impulse responses;
• combining the aligned channel impulse responses to generate a combined channel impulse response;
• and
• estimating the combined time of arrival from the combined channel impulse response.

A non-transitory computer-readable medium having stored therein instructions that, when executed by at least one physical computing device, perform a method for estimating one or more characteristic differences between two wireless signals, the method comprising:

• receiving a first wireless signal transmitted in a first frequency range;
• receiving a second wireless signal transmitted in a second frequency range, wherein the second frequency range is spaced from the first frequency range, and wherein the second wireless signal is transmitted from the same location as the first wireless signal;
• processing the first wireless signal and the second wireless signal to estimate the one or more characteristic differences between them, the one or more characteristic differences comprising at least one or any combination of two or more of:
• a relative offset in their time of transmission,
• a relative carrier phase relationship between them, and
• a relative amplitude relationship between them, and
• estimating a combined time of arrival for the first wireless signal and the second wireless signal, wherein estimating the combined time of arrival is based on the first wireless signal, the second wireless signal, and the one or more characteristic differences, and wherein estimating the combined time of arrival comprises:
• aligning a first channel impulse response and a second channel impulse response, based on the one or more characteristic differences, to generate aligned channel impulse responses;
• combining the aligned channel impulse responses to generate a combined channel impulse response;
• and
• estimating the combined time of arrival from the combined channel impulse response.

An electronic communications device for estimating one or more characteristic differences between two wireless signals, comprising:

• a first receiver, configured to receive a first wireless signal transmitted in a first frequency range;
• a second receiver, configured to receive a second wireless signal transmitted in a second frequency range, wherein the second frequency range is spaced from the first frequency range, and wherein the second wireless signal is transmitted from the same location as the first wireless signal;
• and
• a processor, configured to process the first wireless signal and the second wireless signal to estimate the one or more characteristic differences between them, the one or more characteristic differences comprising at least one or any combination of two or more of:
• a relative offset in their time of transmission;
• a relative carrier phase relationship between them;
• and
• a relative amplitude relationship between them,
• wherein estimating the one or more characteristic differences comprises:
• estimating a combined time of arrival for the first wireless signal and the second wireless signal, wherein estimating the combined time of arrival is based on the first wireless signal, the second wireless signal, and the one or more characteristic differences, and wherein estimating the combined time of arrival comprises:
• aligning a first channel impulse response and a second channel impulse response, based on the one or more characteristic differences, to generate aligned channel impulse responses;
• combining the aligned channel impulse responses to generate a combined channel impulse response;
• and
• estimating the combined time of arrival from the combined channel impulse response.

An electronic communications device comprising:

• a first receiver, configured to receive a first wireless signal transmitted in a first frequency range;
• a second receiver, configured to receive a second wireless signal transmitted in a second frequency range, wherein the second frequency range is spaced from the first frequency range, and wherein the second wireless signal is transmitted from the same location as the first wireless signal;
• and
• a processor, configured to:
• obtain one or more characteristic differences between the first wireless signal and the second wireless signal, and
• estimate a combined time of arrival for the first wireless signal and the second wireless signal, based on:
• the first wireless signal, the second wireless signal, and the one or more characteristic differences,
• wherein estimating the combined time of arrival further comprises:
• aligning a first channel impulse response and a second channel impulse response, based on the one or more characteristic differences, to generate aligned channel impulse responses;
• combining the aligned channel impulse responses, to generate a combined channel impulse response;
• and
• estimating the combined time of arrival from the combined channel impulse response.