Patent ID: 7668046

Claim:
An apparatus for determining the spatial position of a transmitter, the apparatus comprising: a transmitter having a spatial position in 3-dimensional space, said transmitter operative to transmit a wireless signal having a predetermined waveform at a predetermined frequency, said transmitter being able to be moved in said 3-dimensional space; a transducer array including a plurality of transducers, each of said plurality of transducers having a spatial location set in a 3-dimensional space and wherein one of said plurality of transducers being a reference transducer, each of said plurality of transducers being wirelessly coupled to said transmitter, each of said plurality of transducers operative to receive said wireless signal and to convert said received wireless signal into an electrical signal having a signal envelope; a plurality of receivers each coupled to a corresponding one of said plurality of transducers and operative to receive said electrical signal therefrom, each of said receivers being operative to convert said electrical signal into a baseband signal and wherein said plurality of receivers provides a plurality of baseband signals as an output; a digital signal processor coupled to said plurality of receivers and operative to receive said plurality of baseband signals therefrom, said digital signal processor operative to: convert each of said plurality of baseband signal from an analog waveform representative of said corresponding baseband signal into a digital representation representative of said corresponding baseband signal; use each of said plurality of digital representations to determine a plurality of time of arrival data each corresponding to the time of arrival of said wireless signal at each of said plurality of transducers; determine a plurality of time difference of arrival data by subtracting each of said plurality of time of arrival data from said time of arrival data corresponding to said reference transducer; determine a set of 3-dimensional spatial coordinates of said transmitter as a function of said plurality of time difference of arrival data and said spatial location of each of said plurality of transducers.