Navigation and positioning system and method using uncoordinated becon signals

In a positioning system that makes use of a multiplicity of transmitters, at known fixed locations, each of which transmits a beacon signal having a phase that is un-synchronized with the phases of the beacon signals of the other transmitters;

• each of said beacon signals having a frequency that is approximately equal to a predetermined target frequency;
• the combination comprising:
• a first receiver, at a known location relative to the locations of said multiplicity of transmitters, which (A) receives said beacon signals, (B) determines the relative phases of said beacon signals, and (C) generates a set of phase data representing said relative phases;
• a second receiver, at an unknown location, which receives at least three of said beacon signals, said second receiver including phase detection circuitry for detecting the phases of said beacon signals at the location of said second receiver;
• computation means, coupled to said second receiver for receiving from said second receiver values corresponding to said detected beacon signal phases, coupled to said first receiver for receiving said generated phase data, and including means for computing the location of said second receiver based on said generated phase values and said detected beacon signal phases;
• and
• initialization means for providing a common timing signal to said first and second receivers in order to establish a common time basis therebetween, said initialization means including means for determining an initial estimate of said unknown location using said common time basis;
• said initialization means including a reference transmitter for transmitting said common timing signal;
• said first receiver including first means for receiving said common timing signal;
• said second receiver including second means for receiving said common timing signal.

In a positioning system that makes use of a multiplicity of transmitters, at known fixed locations, each of which transmits a beacon signal having a phase that is un-synchronized with the phases of the beacon signals of the other transmitters;

• each of said beacon signals having a frequency that is approximately equal to a predetermined target frequency;
• the combination comprising:
• a first receiver, at a known location relative to the locations of said multiplicity of transmitters, which (A) receives said beacon signals, (B) determines the frequency and relative phases of said beacon signals, and (C) which transmits values corresponding to said frequencies and relative phases;
• a second receiver, at an unknown location, which receives said transmitted values from said first receiver and at least four of said beacon signals, said second receiver including phase detection circuitry for detecting the phases of said beacon signals at the location of said second receiver, and computation means for computing the location of said second receiver based on said transmitted values and said detected phases;
• and
• initialization means for providing a common timing signal to said first and second receivers in order to establish a common time basis therebetween, said initialization means including means for determining an initial estimate of said unknown location using said common time basis.

A method of determining a mobile unit's position with respect to the positions of a multiplicity of transmitters that are positioned at known fixed locations, wherein each transmitter transmits a beacon signal having a phase that is un-synchronized with the phases of the beacon signals of the other transmitters;

• each of said beacon signals having a frequency which is approximately equal to a predetermined target frequency;
• the steps of the method comprising:
• at a known location relative to the locations of said multiplicity of transmitters, receiving said beacon signals, determining the relative phases of said beacon signals, and transmitting phase data representing said relative phases;
• at a mobile unit's location, receiving said transmitted phase data and at least three of said beacon signals, detecting the phases of said beacon signals at the location of said mobile unit, and computing the location of said mobile unit based on said transmitted phase data and said detected phases;
• and
• providing a common timing signal to said first and second receivers, said common timing signal being used in said location computing step to provide an initial time value estimate for a time parameter used by said location computing step.

A method of determining a mobile unit's position with respect to the positions of a multiplicity of transmitters that are positioned at known fixed locations, wherein each transmitter transmits a beacon signal having a phase that is un-synchronized with the phases of the beacon signals of the other transmitters;

• each of said beacon signals having a frequency which is approximately equal to a predetermined target frequency;
• the steps of the method comprising:
• at a known location relative to the locations of said multiplicity of transmitters, receiving said beacon signals, determining the relative phases of said beacon signals, and generating phase data representing said relative phases;
• at a mobile unit's location, receiving said at least three of said beacon signals and detecting the phases of said beacon signals at the location of said mobile unit;
• receiving said generated phase data, and computing the location of said mobile unit based on said phase data and said detected phases;
• and
• providing a common timing signal to said first and second receivers, said common timing signal being used in said location computing step to provide an initial time value estimate for a time parameter used by said location computing step.

A positioning system for use with a multiplicity of transmitters that are positioned at known fixed locations, wherein each transmitter transmits a beacon signal having a phase that is un-synchronized with the phases of the beacon signals of the other transmitters;

• each of said beacon signals having a frequency which is approximately equal to a predetermined target frequency;
• said positioning system comprising:
• a first receiver, at a known location relative to the locations of said multiplicity of transmitters, which (A) receives said beacon signals, (B) determines the phases and frequencies of said beacon signals at times determined with reference to a first time reference signal, and (C) transmits phase and frequency data representing said beacon signal phases and frequencies;
• said transmitted phase and frequency data including time data representing when, relative to said first time reference signal, said beacon signals attained said beacon signal phases;
• and
• a second receiver, at an unknown location, which receives said transmitted phase and frequency data from said first receiver and at least three of said beacon signals, said second receiver including
• a local clock generator, un-synchronized with said first time reference signal, that generates a second time reference signal,
• phase detection circuitry for detecting, at times determined with reference to said second time reference signal, the phases and frequencies of said beacon signals at the location of said second receiver, and
• computation means for computing, based on said transmitted phase and frequency data and said detected phases and frequencies, coordinate values defining Said second receiver's position and a time adjustment value for bringing said second time reference signal into alignment with said first time reference signal, Said time adjustment value further relating said detected phases to said transmitted phase data in accordance with a predefined set of simultaneous equations.

A positioning system for use with a multiplicity of transmitters, at known fixed locations, each of which transmits a beacon signal having a phase that is un-synchronized with the phases of the beacon signals of the other transmitters;

• each of said beacon signals having a frequency which is approximately equal to a predetermined target frequency;
• said positioning system comprising:
• a first receiver, at a known location relative to the locations of said multiplicity of transmitters, which (A) receives said beacon signals, (B) determines the phases and frequencies of said beacon signals at times determined with reference to a first time reference signal, and (C) transmits phase and frequency data representing said beacon signal phases and frequencies;
• said transmitted phase and frequency data including time data representing when, relative to said first time reference signal, said beacon signals attained said beacon signal phases;
• a second receiver, at an unknown location, which receives at least three of said beacon signals, said second receiver including:
• a local clock generator, un-synchronized with said first time reference signal, that generates a second time reference signal;
• and
• phase detection circuitry for detecting, at times determined with reference to said second time reference signal, the phases and frequencies of said received beacon signals at the location of said second receiver;
• and
• position computation means which receives said transmitted phase and frequency data from said first receiver and said phases and frequencies detected by said second receiver, said position computing means including means for computing, based on said transmitted phase and frequency data and said detected phases and frequencies, coordinate values defining said second receiver's position and a time adjustment value for bringing said second time reference signal into alignment with said first time reference signal, said time adjustment value further relating said detected phases to said transmitted phase data in accordance with a predefined set of simultaneous equations.