GNSS Multipath Mitigation Algorithm with Antenna Arrays Based on Matrix Reconstruction

Multipath has become a bottleneck to improve the accuracy in GNSS high-precision positioning, because it cannot be mitigated with differencing techniques. Traditional multipath suppression algorithms are especially ineffective on the multipath whose delay with direct signal is less than 0.01 chips. Recently, more scientists have paid attention to the research on the multipath mitigation with antenna arrays using the spatial characteristics of signals. The existing anti multipath methods with antenna array processing algorithm in GNSS system need the assistance of inertial navigation in determining the attitude of the array platform, which causes heavy computing burden. Aiming at the drawbacks, we discuss a matrix reconstruction method of a satellite signal. It reconstructs the input of array algorithms by the results of the pseudocode correlation. It can solve the problem that the signal-to-noise ratio (SNR) of satellite navigation signal is too low to use array algorithm. Adaptive beamforming using the reconstructed satellite signals control array weighting forming the main beam and the null beam. The main beam aim at the satellite directed signal and the null beam aim at the multipath signal, which can achieve the purpose of enhancing the satellite signal and suppressing multipath. Simulation results show that the carrier to noise ratio (C/N0) of the received signal can be increased by about 6 dB. And the pseudorange deviation can be improved by 0.3 to 3m for the multipath signals with chip delay ranging from 0.01 to 0.1.