Methods and systems for performing location determination based on sequence of pulses

Abstract

A surface-based transmitter system for assisting determination of vehicle location is presented. The system comprises a set of radio frequency (RF) transmitter nodes that, when deployed at different respective locations, are configured to output a sequence of respective RF pulses with a predefined inter-pulse delay between each pair of consecutive RF pulses in the sequence, wherein the pre-defined inter-pulse delay is longer than one microsecond. The set of RF transmitter nodes include at least a first RF transmitter node, a second RF transmitter node, a third RF transmitter node, and a fourth RF transmitter node, which are configured to output a first RF pulse, a second RF pulse, a third RF pulse, and a fourth RF pulse, respectively, of the sequence of RF pulses.

We claim: 
     
         1 . A surface-based transmitter system for assisting determination of vehicle location, the system comprising:
 a set of radio frequency (RF) transmitter nodes that, when deployed at different respective locations, are configured to output a sequence of respective RF pulses with a predefined inter-pulse delay between each pair of consecutive RF pulses in the sequence,   wherein the predefined inter-pulse delay is longer than 1 microsecond;   wherein the set of RF transmitter nodes includes at least a first RF transmitter node, a second RF transmitter node, a third RF transmitter node, and a fourth RF transmitter node, which are configured to output a first RF pulse, a second RF pulse, a third RF pulse, and a fourth RF pulse, respectively, of the sequence of RF pulses;   wherein the set of RF transmitter nodes is further configured to transmit the sequence of respective RF pulses in a series of respective non-overlapping time slots;   wherein each RF transmitter node of the set of RF transmitter nodes is configured to output a respective RF pulse at a beginning of a respective time slot, and to further output a respective data signal in the respective time slot after outputting the respective RF pulse;   wherein the respective data signal encodes at least one of the following:   a respective node identifier for the RF transmitter node, or a respective clock value that indicates when the respective RF pulse is outputted by the RF transmitter node; and   wherein each RF transmitter node of the set of RF transmitter nodes is further configured to output the respective data signal after a predefined range gate delay has elapsed since the outputting of the respective RF pulse, and   wherein each RF transmitter node of the set of RF transmitter nodes is further configured to output the respective data signal with a lower transmission power than a transmission power of the respective RF pulse.