Method for suppressing multipath errors in a satellite navigation receiver

An apparatus for suppressing multipath error in a satellite navigation receiver, comprising:

• an analog front end coupled to an antenna;
• a digital circuit in communication with the analog front end;
• and
• a processor in communication with the digital circuit, wherein the apparatus is configured to search for navigation satellites signals, receive and process complex signals from each satellite, track found signals with a following-up open loop and determining coordinates, receiver velocity and exact time based on measurements of direct and reflected signal delay and Doppler frequency, calculate, on the basis of navigation parameters including coordinates, receiver velocity and exact time, and also information on satellite movement obtained on the basis of measured time and received ephemerides, delay and Doppler frequency predictions for orientation of a two-dimensional accumulated power grid according to delay and Doppler frequency, which grid formed on the basis of received and processed complex signals;
• wherein, in the course of grid elements forming, a summation of complex signal is performed in a coherent accumulation interval synchronously with data bits of the given satellite, and the coherent accumulation time is matched with a bit length;
• and
• wherein the apparatus is configured to calculate, on the basis of processing the accumulated power grid including its centering, corrections for delay and Doppler frequency predictions, and calculate delay and Doppler frequency measurements as the sum of predictions and corresponding corrections, then extrapolate obtained measurements for the preset moment of time and calculate pseudorange and pseudovelocity measurements, and determine a receiver coordinates and velocity on the basis of the measurements obtained for all satellites;
• wherein in calculating delay and Doppler frequency corrections, the apparatus is configured to calculate single-path signal corrections using the centered accumulated power grid, determine whether a multipath is presented, and perform improvement of corrections using weights in case of positive result of this determination;
• wherein, performing improvement of corrections using weights is carried out by forming a likelihood function on the basis of a centered accumulated powers vector, and correction is performed according to the found likelihood function global maximum.