Detection and estimation of direct and reflected navigation satellite signal parameters in a multipath environment

A method, comprising:

• identifying, using a computing system of a user device, two or more signal peaks that fall within a tracking aperture spanning a first set of code delay values along a first dimension and a first set of frequency offset values along a second dimension based on analysis of a plurality of signals received from a first satellite, each of the plurality of signals travelling along a different path between the first satellite and the user device within a multipath (“MP”) environment, the identified two or more signal peaks corresponding to two or more signals, among the plurality of signals, whose relative code delay and relative frequency offset fall within the first set of code delay values and the first set of frequency offset values of the tracking aperture;
• determining, using the computing system, one or more peak parameter estimates for each of at least one signal peak based on measurement of signal parameters from the at least one signal peak among the identified two or more signal peaks;
• providing, using the computing system, the determined one or more peak parameter estimates for each of the at least one signal peak to a position engine (“PE”) of the user device that is configured to calculate a navigation solution for the user device based at least in part on the determined one or more peak parameter estimates;
• storing or storing and accumulating a current scalar grid energy value for each of plurality of frequency bins for each of the plurality of code taps, stored by code tap along a first dimension of the 2D array and by frequency bin along a second dimension of the 2D array, in an energy grid buffer (“EGB”) of the satellite navigation device;
• and
• based on a determination that two or more energy peaks occur, that one of the two or more energy peaks is determined to be a direct line-of-sight (“LOS”) signal, and that the other energy peaks among the two or more energy peaks are determined to be one or more reflected non-line-of-sight (“NLOS”) signals, and in response to a determination that the direct LOS signal has been lost, determining a predicted code tap and a predicted frequency bin corresponding to the lost direct LOS signal, based on an extrapolation of the identified at least one location within the EGB corresponding to the direct LOS signal prior to being lost, and generate a pseudo-LOS signal based on the determined predicted code tap and the determined predicted frequency bin.

A satellite navigation device, comprising:

• a computing system, comprising:
• at least one first processor;
• and
• a first non-transitory computer readable medium communicatively coupled to the at least one first processor, the first non-transitory computer readable medium having stored thereon computer software comprising a first set of instructions that, when executed by the at least one first processor, causes the computing system to:
• identify two or more signal peaks that fall within a tracking aperture spanning a first set of code delay values along a first dimension and a first set of frequency offset values along a second dimension based on analysis of a plurality of signals received from a first satellite, each of the plurality of signals travelling along a different path between the first satellite and the satellite navigation device within a multipath (“MP”) environment, the identified two or more signal peaks corresponding to two or more signals, among the plurality of signals, whose relative code delay and relative frequency offset fall within the first set of code delay values and the first set of frequency offset values of the tracking aperture;
• determine one or more peak parameter estimates for each of at least one signal peak based on measurement of signal parameters from the at least one signal peak among the identified two or more signal peaks;
• provide the determined one or more peak parameter estimates for each of the at least one signal peak to a position engine (“PE”) of the satellite navigation device that is configured to calculate a navigation solution for the satellite navigation device based at least in part on the determined one or more peak parameter estimates;
• store or store and accumulate a current scalar grid energy value for each of plurality of frequency bins for each of the plurality of code taps, stored by code tap along a first dimension of the 2D array and by frequency bin along a second dimension of the 2D array, in an energy grid buffer (“EGB”) of the satellite navigation device;
• and
• based on a determination that two or more energy peaks occur, that one of the two or more energy peaks is determined to be a direct line-of-sight (“LOS”) signal, and that the other energy peaks among the two or more energy peaks are determined to be one or more reflected non-line-of-sight (“NLOS”) signals, and in response to a determination that the direct LOS signal has been lost, determine a predicted code tap and a predicted frequency bin corresponding to the lost direct LOS signal, based on an extrapolation of the identified at least one location within the EGB corresponding to the direct LOS signal prior to being lost, and generate a pseudo-LOS signal based on the determined predicted code tap and the determined predicted frequency bin.