Multipath Mitigation Technique Based on Successive Variational Mode Decomposition Using NAVIC Receiver Data

Multipath interference poses a significant challenge in satellite-based navigation systems, including NAVIC (Navigation with Indian Constellation), degrading the accuracy of position estimates. This study proposes a comprehensive approach to address multipath errors in NavIC receivers, combining multipath error calculation using the code minus carrier method with multipath reduction through mode decomposition techniques EMD- empirical mode decomposition, VMD-variational mode decomposition, and SVMD-successive variational mode decomposition. Data was collected from a NavIC receiver located at KLEF University in Guntur, India with latitude 16.44 N, and longitude 80.62 E during the period from April 12th to 14th, 2017. Initially, multipath errors are calculated by subtracting NavIC carrier phase measurements from code phase measurements, providing insights into the magnitude of multipath interference. Subsequently, the received signal is decomposed using EMD, VMD, and SVMD to extract intrinsic modes or oscillatory components representing different signal characteristics. The direct signal is reconstructed by selectively filtering or removing multipath-related modes, reducing multipath interference. To evaluate the effectiveness of each decomposition method, the SDE (standard deviation error) of the reconstructed multipath signal is computed. The decomposition method yielding the lowest SDE is identified as the optimal approach for multipath reduction in NavIC receivers. By integrating the code minus carrier method with mode decomposition techniques, significant enhancements in navigation performance can be achieved, facilitating reliable and precise positioning for various applications.