Method and system for multipath reduction for wireless synchronization and/or locating

A tangible, non-transitory, machine-readable medium storing instructions that when executed by one or more computing devices effectuate operations comprising:

• receiving, with a computer system, a set of time-of-arrival (TOA) stamps,
• wherein the set of TOA stamps comprises:
• a first subset of TOA stamps indicative of a first time of reception of a first broadcast message broadcasted from a first location anchor and a second time of reception of a second broadcast message broadcasted from a second location anchor;
• and
• a second subset of TOA stamps based on a first self-reception time of the first broadcast message by the first location anchor and a second self-reception time of the second broadcast message by the second location anchor,
• wherein the second subset of TOA stamps have smaller multipath error than the first subset of TOA stamps, and
• wherein the TOA stamps are delivered in association with information indicative of the location anchor broadcasting each broadcast message having a TOA stamp among the set of TOA stamps;
• identifying the location anchor broadcasting each broadcast message having a TOA stamp among the set of TOA stamps based on the information;
• calculating, with the computer system, time-difference-of-arrival (TDOA) values based on the first subset of TOA stamps and the second subset of TOA stamps;
• determining, with the computer system, a first set of parameters that define a first clock model function using at least two of the TDOA values, wherein the first clock model function utilizes a time dependence factor of the TDOA values associated with the first broadcast message and the second broadcast message;
• and
• calculating, with the computer system, using the first clock model function, an phase difference from the first clock model function and from a time elapsed between a first reference point in time and a second reference point in time.

A system, comprising:

• a first location anchor configured to broadcast a first broadcast message, self-receive the first broadcast message, and determine a first self-reception time of the self-received first broadcast message;
• and
• a second location anchor configured to broadcast a second broadcast message, self-receive the second broadcast message, and determine a second self-reception time of the self-received second broadcast message,
• wherein the second location anchor receives the first broadcast message, the first location anchor receives the second broadcast message, and the first location anchor and the second location anchor generate a first set of time-of-arrival (TOA) stamps indicative of respective times of reception of the first broadcast message and the second broadcast message and a second set TOA stamps indicative of the first self-reception time and the second self-reception time;
• and
• a server configured to:
• receive the first set of TOA stamps and the second set of TOA stamps;
• identify, based on a first identifier of the first location anchor sent to the server with a first TOA stamp of the first set of TOA stamps, the first location anchor broadcasting a broadcast message corresponding to the first TOA stamp;
• calculate time-difference-of-arrival (TDOA) values based on the first set of TOA stamps and the second set of TOA stamps;
• and
• calculate a phase difference, according to a first clock model function, between time bases of the first location anchor and the second location anchor.

A method, comprising:

• receiving, by a computing device, a set of time-of-arrival (TOA) stamps,
• wherein the set of time stamps comprises:
• a first subset of TOA stamps indicative of a first time of reception of a first broadcast message broadcasted from a first location anchor and a second time of reception of a second broadcast message broadcasted from a second location anchor, and
• a second subset of TOA stamps based on a first self-reception time of the first broadcast message by the first location anchor and a second self-reception time of the second broadcast message by the second location anchor,
• wherein the second subset of TOA stamps have smaller multipath error than the first subset of TOA stamps, and
• wherein the TOA stamps are delivered in association with information indicative of the location anchor broadcasting each broadcast message having a TOA stamp among the set of TOA stamps;
• identifying, by the computing device, the location anchor broadcasting each broadcast message having a TOA stamp among the set of TOA stamps based on the information;
• calculating, by the computing device, time-difference-of-arrival (TDOA) values based on the first subset of TOA stamps and the second subset of TOA stamps;
• determining, by the computing device, a first set of parameters that define a first clock model function using at least two of the TDOA values, wherein the first clock model function-utilizes-a time dependence factor of the TDOA values associated with the first broadcast message and the second broadcast message;
• and
• calculating, by the computing device and using the first clock model function, an phase difference from the clock model function and from a time elapsed between a first reference point in time and a second reference point in time.