Methods and apparatus for identifying asset location in communication networks

A method for identifying a location of an asset in a communication network, said network having at least a first receiver device and a second receiver device, each receiver device having a known position, said method comprising:

• receiving a data signal at each receiver;
• demodulating said received signal;
• decoding said signal to form a decoded signal;
• optionally selecting a correlation function for said decoded signal if said data signal is not encoded for time-stamping;
• estimating a first time-of-arrival using said correlation function, said first time-of-arrival corresponding to arrival at said first receiver device of a communication sequence transmitted by said asset;
• estimating a second time-of-arrival using said correlation function, said second time-of-arrival corresponding to arrival at said second receiver device of said communication sequence;
• and
• calculating a first time-difference-of-arrivals using said first and second times-of-arrival.

A method for identifying a location of an asset in a communication network, said network having at least three receivers, said method comprising:

• decoding a data signal from said asset to form a decoded signal;
• determining if said decoded signal is encoded for time-stamping;
• selecting a correlation function for estimating a time-of-arrival of a communication sequence at said receivers if said decoded signal is not encoded for time stamping;
• collecting at least one time-of-arrival estimate for each of said receivers using said correlation function, said estimate corresponding to a time-of-arrival of said communication sequence at a respective one of said receivers;
• calculating a difference for each of at least two pairs of said estimates;
• and estimating said location using said differences.